Note: This Walleye Pollock Acoustic Trawl Survey is a way to estimate the amount of fish that are present in a targeted area of the Bering Sea. NOAA Scientists have been conducting these surveys since the 1970’s. It is important work necessary to manage the pollock population. (Pollock is a billion dollar food industry, thus a very important ocean resource.) These population estimates are part of the information used to determine how much fish can be caught in the Bering Sea (fishing quotas, MSY-Maximum Sustainable Yield) that still allows the population to reproduce and survive in adequate numbers.
What does it take to prepare for an Acoustic Trawl Survey?
The fisheries scientists plan their sampling area based upon past surveys so that each part of the Bering Sea is covered over a period of time, in this case June through August;decisions must be made about who will be going on which leg of each trip. They also determine what research projects will be conducted, what specimens should be collected, and what information they need to obtain from this work. Other scientists also make requests, such as specimen collections or oceanography equipment deployments in target areas to obtain information for their own research projects. A document called Project Instructions is developed to include these cruise objectives and a list of all the supplies and equipment needed to conduct the research projects. Once the Project Instructions document is complete, it must be sent for review to NOAA administration, then to MOC-P (Marine Operations Center-Pacific)- which is a home location for NOAA to monitor its’ fleet of NOAA vessels. Now on to the NOAA Corps officers who are also preparing the ship for this cruise. In cases of requesting to sample the western Bering Sea (near, but outside of Russian waters), the State Department must approve it. Once this plan has been approved, many preparation activities begin.
A detailed spreadsheet is developed that lists all supplies needed for the fishing and research work. This includes vials for sampling, chemicals for preserving, tools needed to conduct research, and fishing gear. Some supplies are loaded on the ship when in port in Dutch Harbor or Kodiak, but other supplies are shipped in shipping containers or flatbed trailers. A large ship carries these on the ocean from Seattle to Dutch Harbor, and then tractor trailers bring the nets to the ship.
Then scientists work with the ship’s crew to make final decisions regarding haul locations. While the general area to fish is determined prior to setting sail, specific haul locations (along survey tracklines or transects) are determined as the scientists monitor the location and distribution of fish using sonar readings during sailing.
I am enjoying life at sea and settling into the maritime routines that ensure the ship runs smoothly. NOAA ship Oscar Dyson is a small city with each person having very specific responsibilities for safety and operations. There are approximately 30 people on board. My work shift is from 4pm – 4 am each day. (There are no days off.) The ship has 5 labs (Wet lab, Dry lab, Acoustics Lab, Chemical Lab, Fish Lab) I spend my work shift after each haul, in the fish lab. There we identify the species that are caught, collect specimens for research and record weights and measurements of targeted species. This allows calculation of the amount of each species caught, which are used to calculate population estimates. (This is called processing the catch.) I also spend time writing blog posts, planning lessons about the work here, and interviewing staff on board to learn about their career paths. I will also use this information to teach students about the science related to this work and the career opportunities in this field. Well, a net is being pulled up now, so off to the fish lab I go.
Did You Know?
Sonar readings can be used to “see” what is in the water column. This is due to sound waves that bounce off what is in the water (“echoes”). Strong echoes come from pollock because sound waves bounce off the gas in their swim bladders. These echoes can be shown on a computer screen as the ship sails along, making a plot called an “echogram”.
NOAA Teacher at Sea Andrea Schmuttermair Aboard NOAA Ship Oscar Dyson July 6 – 25, 2015
Mission: Walleye Pollock Survey Geographical area of cruise: Gulf of Alaska Date: July 12, 2015
Weather Data from the Bridge: Latitude: 55 25.5N
Longitude: 155 44.2W
Sea wave height: 2ft
Wind Speed: 17 knots
Wind Direction: 244 degrees
Air Temperature: 11.4 C
Barometric Pressure: 1002.4 mbar
Science and Technology Log
I’m sure you’re all wondering what the day-to-day life of a scientist is on this ship. As I said before, there are several projects going on, with the focus being on assessing the walleye pollock population. In my last post I talked about the transducers we have on the ship that help us detect fish and other ocean life beneath the surface of the ocean. So what happens with all these fish we are detecting?
The transducers are running constantly as the ship runs, and the information is received through the software on the computers we see in the acoustics lab. The officers running the ship, who are positioned on the bridge, also have access to this information. The scientists and officers are in constant communication, as the officers are responsible for driving the ship to specific locations along a pre-determined track. The echograms (type of graph) that are displayed on the computers show scientists where the bottom of the ocean floor is, and also show them where there are various concentrations of fish.
When there is a significant concentration of pollock, or when the data show something unique, scientists might decide to “go fishing”. Here they collect a sample in order to see if what they are seeing on the echogram matches what comes up in the catch. Typically we use the Aleutian wing trawl (AWT) to conduct a mid-water trawl. The AWT is 140 m long and can descend anywhere from 30-1,000 meters into the ocean. A net sounder is mounted at the top of the net opening. It transmits acoustic images of fish inside and outside of the net in real time and is displayed on a bridge computer to aide the fishing operation. At the entrance to the codend (at the end of the net) a CamTrawl takes images of what is entering the net.
Once the AWT is deployed to the pre-determined depth, the scientists carefully monitor acoustic images to catch an appropriate sample. Deploying the net is quite a process, and requires careful communication between the bridge officers and the deck crew. It takes about an hour for the net to go from its home on deck to its desired depth, and sometimes longer if it is heading into deeper waters. They aim to collect roughly 500 fish in order to take a subsample of about 300 fish. Sometimes the trawl net will be down for less than 5 minutes, and other times it will be down longer. Scientists are very meticulous about monitoring the amount of fish that goes into the net because they do not want to take a larger sample than needed. Once they have determined they have the appropriate amount, the net is hauled back onto the back deck and lowered to a table that leads into the wet lab for processing.
We begin by sorting through the catch and pulling out anything that is not pollock. We don’t typically have too much variety in our catches, as pollock is the main fish that we are after. We have, however, pulled in a few squid, isopods, cod, and several jellies. All of the pollock in the catch gets weighed, and then a sub-sample of the catch is processed further. A subsample of 30 pollock is taken to measure, weigh, collect otoliths from, and occasionally we will also take ovaries from the females. There are some scientists back in the lab in Seattle that are working on special projects related to pollock, and we also help these scientists in the lab collect their data.
The rest of the sub-sample (roughly 300 pollock) is sexed and divided into a male (blokes) and female (sheilas) section of the table. From there, the males and females are measured for their length. The icthystick, the tool we use to measure the length of each fish, is pretty neat because it uses a magnet to send the length of the fish directly to the computer system we use to collect the data, CLAMS. CLAMS stands for Catch Logger for Acoustic Midwater Survey. In the CLAMS system, a histogram is made, and we post the graphs in the acoustics lab for review. The majority of our pollock so far have been year 3. Scientists know this based on the length of pollock in our catch. Once all of the fish have been processed, we have to make sure to clean up the lab too. This is a time I am definitely thankful we have foul weather gear, which consists of rubber boots, pants, jackets and gloves. Fish scales and guts can get everywhere!
I am finally adjusting to my nighttime shift schedule, which took a few days to get used to. Luckily, we do have a few hours of darkness (from about midnight until 6am), which makes it easier to fall asleep. My shift runs from 4pm-4am, and I usually head to bed not long after my shift is over, and get up around noontime to begin my day. It’s a little strange to be waking up so late in the day, and while it is clearly afternoon time when I emerge from my room, I still greet everyone with a good morning. The eating schedule has taken some getting used to- I find that I still want to have breakfast when I get up. Dinner is served at 5pm, but since I eat breakfast around 1 or 2pm, I typically make myself a plate and set it aside for later in the evening when I’m hungry again. I’ll admit it’s a little strange to be eating dinner at midnight. There is no shortage of food on board, and our stewards make sure there are plenty of snacks available around the clock. Salad and fruit are always options, as well as some less healthy but equally tasty snacks. It’s hard to resist some of the goodies we have!
Luckily, we are equipped with some exercise equipment on board to battle those snacks, which is helpful as you can only walk so far around the ship. I’m a fan of the rowing machine, and you feel like you’re on the water when the boat is rocking heavily. We have some free weights, an exercise bike and even a punching bag. I typically work out during some of my free time, which keeps me from going too crazy when we’re sitting for long periods of time in the lab.
During the rest of my free time, you might find me hanging out in the lounge watching a movie (occasionally), but most of the time you’ll find me up on the bridge watching for whales or other sea life. The bridge is probably one of my favorite places on the ship, as it is equipped with windows all around, and binoculars for checking out the wildlife. When the weather is nice, it is a great place to sit outside and soak in a little vitamin D. I love the fact that even the crew members that have been on this ship for several years love seeing the wildlife, and never tire of looking out for whales. So far, we’ve seen orcas, humpbacks, fin whales, and Dall’s porpoises.
Did you know? Otoliths, which are made of calcium carbonate, are unique to each species of fish.
Where on the ship is Wilson?
Wilson the ring tail camo shark is at it again! He has been exploring the ship even more and made his way here. Can you guess where he is now?
Before we get into detail about data and where all of it ends up, let’s talk acronyms. This trip has been a lot like working in the Special Education world with what we like to call “Alphabet Soup.” We use acronyms a lot and so does the NOAA Science world. Here are a few important acronyms…
AFSC – Alaska Fisheries Science Center (located in Seattle, WA)
MACE – Midwater Assessment and Conservation Engineering Program (also in Seattle)
CLAMS – Catch Logger for Acoustic Midwater Surveys
We recorded data in a program called CLAMS as we processed each haul. The CLAMS (see above: Catch Logger for Acoustic Midwater Surveys) software was written by two NOAA Scientists. Data can be entered for length, weight, sex and development stage. It also assigns a specimen number to each otolith vial so the otoliths can be traced back to a specific fish. This is the CLAMS screen from my very first haul on the Oscar Dyson.
From the Species List in the top left corner you can see I was measuring the length of Walleye Pollock- Adult. In that particular haul we also had Age 2 Pollock, a Chum Salmon and Chrysaora melanaster (a jellyfish or two). There is the graph in the lower left corner that plots the sizes in a bar graph and the summary tells me how many fish I measured – 462! When we finish in the Wet Lab we all exit out of CLAMS and Robert, a zooplankton ecologist working on our cruise, ducks into the Chem Lab to export our data. There were a total of 142 hauls processed during the 2014 Summer Walleye Pollock Survey (June 12 – August 13) so this process has happened 142 times in the last two months!
Next, it is time to export the data we collected onto a server known as MACEBASE. MACEBASE is the server that stores all the data collected on a Pollock survey. Not only will the data I helped collect live in infamy on MACEBASE, all the data collected over the last several years lives there, too. CLAMS data isn’t the only piece of data stored on MACEBASE. Information from the echosounding system, and SBE (Sea-bird Electronics temperature depth recorder) are uploaded as well.
We’ve reached the end of the summer survey. Now what? 142 hauls, two months of echosounder recordings, four Drop TS deployments and 57 CTD’s. There have also been 2660 sets of otoliths collected. Scientists who work for the MACE program will analyze all of this information and a biomass will be determined. What is a biomass? Some may think of it as biological material derived from living or recently living organisms. In this case, biomass refers to the total population of Walleye Pollock in the Bering Sea. In a few weeks our Chief Scientist Taina Honkalehto will present the findings of the survey to the Bering Sea Plan Team.
That team reviews the 2014 NOAA Fisheries survey results and Pollock fishing industry information and makes science-based recommendations to the North Pacific Fishery Management Council, who ultimately decide on Walleye Pollock quotas for 2015. Think about Ohio’s deer hunting season for a minute. Each hunter is given a limit on how many deer they can tag each year. In Pickaway & Ross counties we are limited to three deer – two either sex permits and one antlerless permit. If every deer hunter in Ohio was allowed to kill as many deer as they pleased the deer population could be depleted beyond recovery. The same goes for Pollock in the Bering Sea. Commercial fisheries are given quotas and that is the maximum amount of Pollock they are allowed to catch during a given year. The scientific research we are conducting helps ensure the Pollock population remains strong and healthy for years to come.
Earlier today I took a trip down to the Engine Room. I can’t believe I waited until we were almost back to Dutch Harbor to check out this part of the ship. The Oscar Dyson is pretty much a floating city! Put on some ear protection…it’s about to get loud!
Why must we wear ear protection? That large machine behind me! It is a 3512 Caterpillar diesel engine. The diesel engine powers an electric generator. The electric generator gives power to an electric motor which turns the shaft. There are four engine/generator set ups and one shaft on the Dyson. The shaft turns resulting in the propeller turning, thus making us move! When we are cruising along slowly we can get by with using one engine/generator to turn the shaft. Most of the time we are speeding along at 12 knots, which requires us to use multiple engines/generators to get the shaft going. Here is a shot of the shaft.
The EOS, or Engineering Operation Station, is the fifth location where the ship can be controlled. The other four locations are on the Bridge.
This screen provides Engineers with important info about the generators (four on board) and how hard they’re working. At the time of my tour the ship was running on two generators (#1 and #2) as shown on the right side of the screen. #3 and #4 were secured, or taking a break. The Officer of the Deck, who is on the Bridge, can also see this screen. You can see an Ordered Shaft RPM (revolutions per minute) and an Actual Shaft RPM boxes. The Ordered Shaft RPM is changed by the Officer on Deck depending on the situation. During normal underway conditions the shaft is running at 100-110 RPMs. During fishing operations the shaft is between 30 and 65 RPMs.
When I talked about the trawling process I mentioned that the Chief Boatswain is able to extend the opening of the net really far behind the stern (back) of the ship. This is the port side winch that is reeled out during trawling operations. There are around 4300 meters of cable on that reel! How many feet is that?
When Lt. Ostapenko and ENS Gilman were teaching me how to steer this ship they emphasized how sensitive the steering wheel is. Only a little fingertip push to the left can really make a huge difference in the ship’s course. This is the hydraulic system that controls the rudder, which steers the ship left or right. The actual rudder is hidden down below, under water. I’m told it is a large metal plate that stands twice as tall as me. This tour really opened my eyes to a whole city that operates below the deck I’ve been working on for the last 18 days. Without all of these pieces of equipment long missions would not be possible. Because the Oscar Dyson is well-equipped it is able to sail up to forty days at a time. What keeps it from sailing longer voyages? Food supply!
And just like that I remembered all good things must come to an end. This is the end of the road for the Summer Walleye Pollock Survey and my time with the Oscar Dyson. We have cleaned and packed the science areas of the ship. Next we’ll be packing our bags and cleaning our staterooms. In a matter of hours we’ll be docking and saying our goodbyes. There have been many times over the last 19 days where I’ve stood, staring out the windows of the Bridge and thinking about how lucky I am. I will never be able to express how thankful I am for this opportunity and how it will impact my life for many, many years. A huge THANK YOU goes to the staff of NOAA Teacher at Sea. My fellow shipmates have been beyond welcoming and patient with me. Thank you, thank you, THANK YOU to everyone on board the Dyson!! I wish you safe travels and happy fishing!
To Team Bluefin Tuna (night shift Science Crew), thank you for your guidance, ice cream eating habits, card game instruction, movie watching enthusiasm, many laughs and the phrase “It is time.” Thanks for the memories! I owe y’all big time!
Did you know? The ship also has a sewage treatment facility and water evaporation system onboard. The MSD is a septic tank/water treatment machine and the water evaporation system distills seawater into fresh potable (drinking and cooking) water.
“Whatever,” you shrug.
“Just a fish,” you scorn.
“He’s slimy and has fish for brains,” you mock.
Well, what if I told you that guy there was worth almost one billion dollars in exports alone?
What if I told you that thousands of fishermen rely on this guy to provide for their families?
What if I told you that they were the heart of the Sub-Arctic food web, and that dozens of species would be threatened if they were to disappear?
What if I told you they were all secretly trained ninja fish? Ninja fish that carry ninja swords strapped to their dorsal fins?
Then I’d only be wrong about one thing.
Taina Honkalehto is the Chief Scientist onboard the Oscar Dyson. She has been studying Pollock for the last 22 years. I asked her what was so important about the fish.
“They’re the largest single species fishery in North America,” Taina says. That makes them top dog…err… fish… in the U.S. fishing industry.
“In the U.S. they are fish sticks and fish-wiches (like Filet-o-Fish from McDonalds). They’ve become, foodwise, what Cod used to be… inexpensive, whitefish protein,” Taina continues. They’re also the center of the sub-arctic food web. Seals, walruses, orca, sea lions, and lots of larger fish species rely on Pollock as an energy source.”
But they aren’t just important for America. Pollock plays an important role in the lives of people from all over the Pacific Rim. (Remember that the Pacific Rim is made up of all the countries that surround the Pacific Ocean… from the U.S. and Canada to Japan to Australia to Chile!)
“Pollock provide a lot of important fish products to many countries, including the U.S., Japan, China, Korea, and Russia,” Honkalehto says.
Making sure we protect Pollock is REALLY important. To know what can go wrong, we only have to look at the Atlantic Cod, the fish that Cape Cod was named after. In the last twenty years, the number of Atlantic Cod has shrunk dramatically. It’s cost a lot of fishermen their jobs and created stress in a number of families throughout New England as well as tensions between the U.S. and Canada. The U.S. and Canada share fish populations.
The primary job of the Oscar Dyson is to sample the Pollock population. Government officials use the results to tell fishermen what their quota should be. A quota is a limit on the number of fish you can catch. The way we gather that data, though, can be a little gross.
The Aleutian Wing Trawl (or AWT)
The fishermen guide the massive Aleutian Wing Trawl (or AWT) onto the deck of the ship. The AWT is a 150 meters long net (over one and a half football fields in length) that is shaped like an ice cream cone. The net gets more and more narrow until you get all the way down to the pointy tip. This is known as the “cod end,” and it’s where most of the fish end up. Here’s a diagram that XO (Executive Officer) Kris Mackie was kind enough to find for me.
The AWT is then hooked onto a crane which empties it on a giant mechanical table. The table has a hydraulic lift that lets us dump fish into the wet lab.
Kids, whenever you hear the term “wet lab,” I don’t want you to think of a water park. Wet lab is going to mean guts. Guts and fish parts.
In the wet lab, the contents of the net spills onto a conveyer belt… sort of like what you see at Shaw’s or Market Basket. First we sift through the Pollock and pull any odd things… jellyfish, skates, etc… and set them aside for measurement. Then it’s time to find out what sex the Pollock are.
Genitals on the Inside!
Pollock go through external fertilization (EF). That means that the female lays eggs, and the males come along and fertilize them with their sperm. Because of that, there’s no need for the outside part of the sex organs to look any different. In science, we often say that form follows function. In EF, there’s very little function needed other than a hole for the sperm or egg cells to leave the body.
Because of that, the only way to tell if a Pollock is male or female is to cut them open and look for ovaries and testes. This is a four step process.
Step 1: Slice open the belly of the fish.
Step 2: Push the pink, flippy floppy liver aside.
Step 3: Look for a pair of lobes (a bag like organ) that is either purple, pink, or orange-ish. These are the ovaries! If you find this, you’ve got a female.
Step 4: If you strike out on step 3, look for a thin black line that runs behind the stomach. These are the testes… As Tom Hanks and Meg Ryan might say, you’ve got male.
Then the gender and length of the fish is then recorded using CLAMS… a software program that NOAA computer scientists developed for just this purpose. With NOAA, like any good science program, it’s all about attention to detail. These folks take their data very seriously, because they know that so many people depend on them to keep the fish population safe.
On the first day aboard the Oscar Dyson, we were trained on all matters of safety. Safety on a ship is often driven by sirens sounded by the bridge. Here’s a list of calls, what they mean, and what you should do when you hear them:
What you hear…
What it means…
What you should do…
Three long blasts of the alarm:
Man Over Board
Report to safety station, be counted, and report in to the bridge (unless you’re the one that saw the person go overboard… then you throw them life rings (floaties) and keep pointing at them).
One long blast of general alarm or ship’s whistle:
Fire or Emergency onboard
Report to safety station, be counted, and report in to the bridge. Bring Immersion Suit just in case.
Six or more short blasts then one long blast of the alarm:
Grab your immersion suit, head to the aft (back) deck of the ship, be counted, and prepare to board a life raft.
The immersion suit (the thing that makes me look like lobster gumby, above) is made of thick red neoprene. It has two flashing lights also known as beacons… one of them automatically turns on when it hits water! This helps rescuers find you in case you’re lost in the dark. It also has an inflatable pillow behind your head to help keep your head above water. Mostly just wanted to wear it to Starbucks some day.
Another thing I can tell you about life aboard the Oscar Dyson is that there is plenty to eat!
kind of awesome. For one thing, there is a never ending supply of food in the galley (the ship’s cafeteria). Eva is the Chief Steward on the Oscar Dyson (though I call her the Head Chef!).
You’ll never go hungry on her ship. Dinner last night? barbeque ribs and mac and cheese. Yesterday’s lunch? Steak and chicken fajitas. And this morning? Breakfast burritos with ham and fruit. I know. You were worried that if I lost any weight at sea that I might just disappear. I can confirm for you that this is absolutely not going to happen.
Tune in next time when I take you on a tech tour of the Oscar Dyson!
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 8/8/13
Weather Data from the Bridge (as of 17:00 Alaska Time): Wind Speed: 15.72 knots
Temperature: 13.4 C
Barometric Pressure: 1012.1 mb
Science and Technology Log:
We came. We fished. We measured, counted and weighed. Now What? We completed one last trawl on Tuesday night (August 6th). When we finished we had caught over 65,000 walleye pollock and a whole lot of POP (Pacific ocean perch) on this leg of the survey.
The scientists now process and analyze the data.
Darin and Patrick will present at a public meeting when we are back in Kodiak on Friday. They will discuss what was seen and preliminary findings of the walleye pollock survey. Back in Seattle the MACE team will further evaluate the data along with data from the bottom trawl survey and determine the walleye pollock biomass for the Gulf of Alaska. This will then be taken under advisement by the North Pacific Fishery Management Council.
There is also the lab to clean. Even though we cleaned the lab after each trawl, it needed a good scrub down. There were scales and slime hidden everywhere. Just when you thought you were done, more scales were discovered.
Did You Know?
The note on the white board stated that there will be beam seas tonight. What does that really mean? It means the waves are moving in a direction roughly 90° from our heading. So the water will be hitting us at a right angle to our keel. It will be a rocking boat tonight.
Darin took a sample of the salmon shark’s fin when we caught it. It will be sent to a scientist in Juneau who works at Auke Bay Laboratories (where Jodi works). The sample will be used to examine the population genetics of the salmon shark and other species such as the Pacific sleeper shark.
In my first blog, I wrote about a childhood dream of becoming an oceanographer. After my third year of teaching in the Peace Corps, I decided education was my new direction. I was excited to taste that bygone dream aboard the Oscar Dyson. How do I feel now? I jokingly sent an email to my assistant principal telling her to look for a new science teacher because I love life at sea. I love collecting data in the field. Although I was not responsible for analyzing the data and I do miss my boys, I had an awesome cruise. So where does that leave me?
It leaves me back in the classroom with an amazing sea voyage experience to share with my students. I will always long for that oceanographic career that could have been. But perhaps after my experience, I will inspire future oceanographers and fisheries scientists. And I would do Teacher at Sea again in a heartbeat. I will follow up with the outcomes and biomass estimates from MACE (Mid-Water Assessment & Conservation Engineering) and I will most definitely follow Jodi’s research on the use of multibeam sonar for seafloor mapping.
I want to say thank you to everyone who made my experience one of the best of my life and definitely the best professional development of my career. Thank you to Jennifer Hammond, Elizabeth McMahon, Jennifer Annetta, Emily Susko and Robert Ostheimer for the opportunity to participate in the NOAA Teacher at Sea Program. Thank you to NOAA for developing a practical and realistic opportunity to connect my students to ocean science. Thank you to the science team (Chief Scientist Patrick Ressler, Darin Jones, Paul Walline, Jodi Pirtle, Kirsten Simonsen, and Abigale McCarthy) aboard the Oscar Dyson for their willingness to train me, answer all of my questions, preview my blogs, and to allow me have a glimpse of their lives as scientists. Thank you to Patrick Ressler and XO Chris Skapin for promptly providing feedback on my blogs. And a special thanks to the night shift crew (Jodi, Paul and Darin). I was very nervous about adjusting to my work hours (4 pm to 4 am) especially after falling asleep that first night, but I am very grateful for colleagues who were fascinating and night-time enjoyable. Chats with everyone aboard the Oscar Dyson from fishermen to NOAA Corps to engineers to stewards to scientists were educational and pleasant. I met lots of people from all over the U.S. and some just from Newport (2 hours from Eugene).
WOW. How fortunate was I to be chosen? I am nearly speechless about what I saw and what I did. What a mind blowing three weeks. Thank You! Thank You! Thank You!
Now I begin the transition of living during daylight hours.
I hope everyone was able to sample a little of my adventure. I appreciate everyone who followed my blog especially Camas Country Mill folks.
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 8/7/13
Weather Data from the Bridge (as of 21:00 Alaska Time): Wind Speed: 10.42 knots
Temperature: 13.6 C
Barometric Pressure: 1012.4 mb
Current Weather: A high pressure system is building in the east and the swells will increase to 8 ft tonight.
Science and Technology Log:
Before I begin, I must thank Paul for educating me on the calibration process. Because calibration occurred during the day shift, I was not awake for some of it.
The EK60 is a critical instrument for the pollock survey. The calculations from the acoustic backscatter are what determines when and where the scientists will fish. Also these measurements of backscatter are what are used, along with the estimates of size and species composition from the trawling, to estimate fish biomass in this survey. If the instruments are not calibrated then the data collected would possibly be unreliable.
Calibration of the transducers is done twice during the summer survey. It was done before leg one in June, which began out of Dutch Harbor, and again now near Yakutat as we end leg three and wrap up the 2013 survey.
As we entered Monti Bay last night, Paul observed lots of fish in the echosounder. This could pose a problem during calibrations. The backscatter from the fish would interfere with the returns from the spheres. Fortunately fish tend to migrate lower in the water column during the day when calibrations were scheduled.
This morning the Oscar Dyson moved from Monti Bay, where we stopped last night, into Sea Otter Bay and anchored up. The boat needs to be as still as possible for the calibrations to be successful.
Calibration involves using small metal spheres made either of copper or tungsten carbide.
The spheres are placed in the water under transducers. The sphere is attached to the boat in three places so that the sphere can be adjusted for depth and location. The sphere is moved throughout the beam area and pings are reflected. This backscatter (return) is recorded. The scientists know what the strength of the echo should be for this known metal. If there is a significant difference, then data will need to be processed for this difference.
The 38 khz transducer is the important one for identifying pollock. A tungsten carbide sphere was used for its calibration. Below shows the backscatter during calibration, an excellent backscatter plot.
The return for this sphere was expected to be -42.2 decibels at the temperature, salinity and depth of the calibration The actual return was -42.6 decibels. This was good news for the scientists. This difference was deemed to be insignificant.
Calibration took all of the day and we finally departed at 4:30 pm. The views were breathtaking. My camera doesn’t do it justice. Paul and Darin got some truly magnificent shots.
As we left Yakutat Bay, I finally saw a handful of sea otters. They were never close enough for a good shot. They would also dive when we would get close. As we were leaving, we were able to approach Hubbard Glacier, another breathtaking sight. Despite the chill in the air, we stayed on top getting picture after picture. I think hundreds of photos were snapped this evening.
Did You Know?
According to the National Park Service, Hubbard Glacier is the largest tidewater glacier in North America. At the terminal face it is 600 feet tall. This terminal face that we saw was about 450 years old. Amazing!
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 8/1/13
Weather Data from the Bridge (as of 00:00 Alaska Time): Wind Speed: 12 knots
Temperature: 13 C
Humidity: 97 %
Barometric Pressure: 1021 mb
Science and Technology Log:
The main goal of Leg 3 of this mission is to use acoustics and trawling to survey the mid-water portion of the pollock population along the Gulf of Alaska starting near Kodiak to Yakutat Bay.
Pollock live in the an area between the middle of the water column and the seafloor. Sometimes we sample the mid-water and sometimes we will sample the bottom.
The Oscar Dyson carries three different types of trawling nets for capturing fish as part of the mid-water survey: the Aleutian Wing Trawl (AWT), a mid-water trawl net, the Poly Nor’Eastern (PNE), for bottom trawls and the Methot, which is for gathering samples of very small ocean creatures such as krill. I will focus on the AWT, although some of the video footage is from a bottom trawl.
When the net is deployed from the ship, the first part of the net to hit the water is called the codend. This is where most of the fish end up after the trawl. The mesh size of the net is smallest at the codend (about 1 cm) and gets larger as it approaches the doors (about 1 m).
A Cam Trawl goes in the water next. This is a pair of cameras that help scientists identify and measure the fish that are caught in the net. This technology can also be used to help scientists validate their biomass estimate from trawling sampling counts. This piece of equipment has to be clipped into loops on the trawl each time.
The next piece of the net to hit the water is the “kite” which is secured to the head rope. Here, a series of sensors is attached to help the scientists gather data about the condition of the net including depth, size, and shape underwater. The major acoustic sensor, called the “turtle,” can tell if the fish are actually going into the net.
Once the kite is deployed, a pair of tom weights (each weighing 250 lbs), are attached to the bridal cables to help separate the head rope from the foot rope and ensure the mouth of the net will open. Then, after a good length of cable is let out, the crew transfers the net from the net reel to the two tuna towers and attach the doors. The doors create drag to ensure the net mouth opens wide.
The scientists use acoustic data to determine at what depth they should fish, then the OOD (Officer on Deck) uses a scope table to determine how much cable to let out in order to reach our target depth. Adjustments to the depth of the head rope can be made by adjusting speed and/or adjusting the length of cable released.
The scientists use the acoustic data sent from the “turtle” to determine when enough fish are caught to have a scientifically viable sample size, then the entire net is hauled in.
Once on board, the crew uses a crane to lift the cod end over to the lift-table. The lift-table then dumps the catch into the fish lab where the fish get sorted on a conveyor belt.
The Oscar Dyson needed to pick up materials for a net repair so we headed into Prince William Sound towards Valdez. The area was spectacular.
The sun was out and the skies were blue for most of the day. Although we have had very calm seas, we have been under clouds for most of the last few days.
The absolute highlight of the day was spotting Dall porpoises and filming them bow surfing.
Here are snapshots of the day. The area was so impressive that I have several hundred pictures. Here are just a few:
I am reminded of the Exxon Valdez oil spill devastation.
Did You Know?
The Exxon Valdez (oil tanker) ran aground on Bligh Reef in Prince William Sound, Alaska on March 24, 1989.
The amount of oil spilled into this pristine environment exceeded 11 million gallons of crude oil and affected over 1300 miles of shoreline. According to OCEANA, as many as 2,800 sea otters, 300 harbor seals, 900 bald eagles and 250,000 seabirds died in the days following the disaster.
Jodi, who works the night shift with me, grew up in Cordova, Alaska and as a child remembers the smell of the disaster and the fears in her town (many were fishermen).
Has the area recovered? Part of the settlement with Exxon established a fund to support research. Read more.
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 7/28/13
Weather Data from the Bridge (as of 18:00 Alaska Time): Wind Speed: 15.61 knots
Temperature: 13.71 C
Barometric Pressure: 1023 mb
Science and Technology Log:
How do scientists use acoustics to locate pollock and other organisms?
Scientists aboard the NOAA Research Vessel Oscar Dyson use acoustics, to locate schools of fish before trawling. The Oscar Dyson has powerful, extremely sensitive, carefully calibrated, scientific acoustic instruments or “fish finders” including the five SIMRAD EK60 transducers located on the bottom of the centerboard.
This “fish-finder” technology works when transducers emit a sound wave at a particular frequency and detect the sound wave bouncing back (the echo) at the same frequency. When the sound waves return from a school of fish, the strength of the returning echo helps determine how many fish are at that particular site.
Sound waves bounce or reflect off of fish and other creatures in the sea differently. Most fish reflect sound energy sent from the transducers because of their swim bladder<s, organs that fish use to stay buoyant in the water column.
These reflections of sound (echoes) are sent to computers which display the information in echograms. The reflections showing up on the computer screen are called backscatter. The backscatter is how we determine how dense the fish are in a particular school. Scientists take the backscatter that we measure from the transducers and divide that by the target strength for an individual and that gives the number of individuals that must be there to produce that amount of backscatter. For example, a hundred fish produce 100x more echo than a single fish. This information can be used to estimate the pollock population in the Gulf of Alaska.
The trawl data provide a sample from each school and allow the NOAA scientists to take a closer look by age, gender and species distribution. Basically, the trawl data verifies and validates the acoustics data. The acoustics data, combined with the validating biological data from the numerous individual trawls give scientists a very good estimate for the entire walleye pollock population in this location.
How I spent my shift on Saturday, July 27th?
When I arrived at work at 4 pm, a decision was made to trawl for krill. A methot trawl is used to collect krill.
Then we set to work processing the catch. First we have to suit up in slime gear because the lab will get messy. My previous blog mentioned not wanting to count all of the krill in the Gulf of Alaska. But in this case we needed to count the krill and other species that were collected by the methot trawl.
How many krill do you think we collected?
Patrick, the lead scientist, put a few specimens under the microscope so we could see the different types of krill.
The collection of krill was preserved in formaldehyde and sea water. It will be sent to Poland for further species diagnosis.
As the ship continued back on transect, I wandered in to see what Jodi and Darin were doing with the data collected last night. Jodi was processing data from the multibeam sonar and Darin was surveying the images from the drop camera. Jodi was very patient explaining what the data means. I will write more about that later. But I did feel quite accomplished as I realized my understanding was increasing.
A decision was made to do another methot trawl. This time we had a huge sample.
In an approximately 50 gram sample we counted 602 individual krill. Compare this to the 1728 individuals in a 50 gram sample from the first trawl. They were much bigger this time. The total weight of the entire sample of krill was 3.584 kilograms.
How many individuals were collected in the second trawl? (Check your answer at the end of the blog)
Around midnight, Paul decided to verify an echogram by trawling.
We collected data from the trawl net and the pocket net.
The pocket net catches the smaller organisms that escape through the trawl net.
It was after 2 am by the time we had processed catch and washed down the lab. The internet was not available for the rest of my shift due to the ship’s position so I organized my growing collection of videos and pictures.
I wasn’t sure how I would handle my night shift (4 pm to 4 am) after I dozed off during the first night. Now that I have adjusted, I really enjoy the night shift. The night science team of Paul, Darin and Jodi are awesome.
Did You Know?
People who are on the Oscar Dyson live throughout the United States. They fly to meet the boat when they are assigned a cruise. Jodi is from Juneau, Alaska. Paul is from Seattle, Washington. And Darin is from Seattle/North Carolina. There are a number who are based out of Newport, Oregon.
Something to Think About:
When we are fishing, a number of birds gather behind the boat. What different sea birds are observable this time of the year in our survey area?
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 7/27/13
Weather Data from the Bridge (at 1:00 am Alaskan time):
Wind Speed = 3.52 knots
Air Temperature = 13.6 C
Humidity = 94%
Barometric Pressure = 1025.5 mb
Science and Technology Log:
How can you determine the population size of species?
You could count every member of the population. This would be the most accurate but what if the population moves around a lot? What if the population is enormous and requires too much time to count each and every one? Would you want to count all of the krill in the Gulf of Alaska?
You could mark and recapture. In this method you catch individuals from the population and tag them. Data are compiled from the recaptures and the population is mathematically calculated. Halibut and many other populations are monitored this way and require fishermen to report any recaptures.
Another method is sampling. The organisms in a small area are counted and then the overall population in the entire area is calculated.
This picture above illustrates the use of a transect line. On various increments along the transect line, samples of populations are taken. Imagine the Oscar Dyson’s path as the measuring tape and the trawl net as the sampling square.
The overall survey area of the pollock study this summer is the northern Gulf of Alaska between the shore and the continental break. Within this area transect lines were established. These are pathways that the Oscar Dyson will travel along and periodically take samples of the fish.
The current set of transects are 25 nautical miles (1 nautical mile is equal to 1 minute of latitude) apart and are parallel but transects in other areas may be 2 or 5 miles apart. Transects that we are following now are located on the shelf and are perpendicular to the coastline. Transects in inlets and bays may run differently and may even zigzag.
If fish are located through acoustics, the ship will break transect (a mark is made on the map) and the ship will circle around and a sample of the population is taken by trawling. The population of pollock can then be mathematical calculated. After trawling, the ship will return to the break and continue along the transect line.
This afternoon, we were working smaller transect lines near Amatuli Trench that were 6 miles apart. It is an area that has had good pollock catches. Just when we were going to fish, a pod of fin whales was spotted in the area. So we moved to another area and hauled in quite the catch of Pacific Ocean perch.
It is hopeful that the Oscar Dyson will finish a transect line by nightfall and then the ship can be at the next transect by sunrise. This maximizes the time looking for fish and trawling.
I am settling into life on the Oscar Dyson and have established a routine that will support my night shift (4 pm to 4 am). So how do I spend 24 hours on the ship?
I wake up around 11:45 in the morning to be able to eat lunch that is served only between 11:00 and 12:00. Because of the shift schedules, some people are bound to miss one or more of the meals. I miss breakfast because I am sleeping. We are able to request a plate of food be saved for later.
Between the end of lunch and the start of my shift, there are several things that I can do. The weather has been very nice and so I often go on deck to soak up the sun and whale watch.
I may need to do laundry as my clothes start to smell fishy.
I will also workout in one of the two gyms. The gym at the back of the boat can’t be used when trawling because of the high noise level. There is a rower, two exercise bikes, two treadmills, a cross trainer, mats and weights. I got lucky and someone installed a makeshift pull up bar.
There is also a lounge where I can read or watch DVDs. Some of the movies are still in theaters.
An hour before my shift starts, I read and take a short nap. Then, I grab a cup of coffee at 4 pm as my shift starts. I listen as the day shift fills in the evening shift about the happenings of the last 12 hours.
During my shift, there are several things that I may do. If we have fished, there will be pollock and other organisms to process.
After processing, we need to clean up the fish lab which involves spraying down everything include ourselves with water to remove scales and slime.
I also keep an eye on the acoustic monitors, to see what I can recognize. Paul and Darin are always willing to answer my questions (even the ones I already asked).
I may look at trawl camera footage or observe camera drops. Drop Camera
I also have time to work on my blog.
Dinner is served at 5 pm but the mess is always open and is filled with snacks such as sandwich fixings, ice cream, yoghurt, a salad bar and pop tarts.
Whenever I get hungry at night, I just head for the mess. It is a time that I am able to chat with the crew and NOAA Corps as they come in for snacks too.
At 4 am, I make it a point to head directly to my stateroom and go to sleep. The room has a window but I can close the curtains on the portlight (window) and around my bed.
There are no weekends out here. Everyone works 7 days a week for the duration of the cruise.
Did You Know?
Usually fin whales show only their back as they surface for air. Check out my video clip and see if you can spot the whale. It wasn’t too close.
Mission: Walleye Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: July 22, 2013
Weather Data from the Bridge: (7/23/13 at 11 pm) Wind Speed = 13 knots
Air Temperature = 12.7 C
Humidity = 93%
Barometric Pressure = 1017 mb
Science and Technology Log:
There is a great deal of hope to complete the survey, which is supposed to end near Yakutat in the southeast of Alaska. It began near the islands of Four Mountains during leg 1. We are on leg 3, the final leg this summer. Leg 3 began in Kodiak. Three Legs of the Survey
The purpose of this cruise is to survey the walleye pollock (Theragra chalcogramma)in the Gulf of Alaska. Pollock is a significant fishery in the United States as well as the world. Pollock is processed into fish sticks, fish patties and imitation crab. Last year, about 3 million tons of pollock were caught in North Pacific. The scientists on board will collect data to determine the pollock biomass and age structure. These data are used with results from other independent surveys to establish the total allowable pollock catch.
According to the Alaska Fisheries Science Center, pollock can grow to about 3 ½ feet and weigh about 13 lbs. More typically the pollock are approximately 50 cm (20 in) and weigh .75 kg (1.7 lbs). They live in the water column and feed on krill, zooplankton and other crustaceans. As they age they will eat juvenile pollock and other small fishes such as capelin, eulachon and herring as well. Sexual maturity is reached around age 4. Spawning and fertilization occurs in the water column in early spring. The eggs stay in the water column and once hatched are part of the zooplankton until they are free swimming.
The general process used to catch the pollock involves multiple parts. I will break down those steps in a series of blogs. But basically, acoustics are used to locate fish in the water column. Once the scientists have located the fish along the transect (transects are the paths that the ship will travel on so the scientists can collect data), the Oscar Dyson sets out a trawl equipped with a camera. The trawl is brought in and data from the catch is documented. And then the ship continues on.
Trawling is usually completed only during daylight hours. Fortunately the sun does not set here in Alaska right now until after 10 pm. When it is dark, work aboard the Oscar Dyson continues. Jodi is documenting the sea floor with a drop camera. She is looking at life that is there as well as potential threats to the trawl nets for the bottom trawl surveys.
How do scientists use acoustics to locate pollock?
How are the transects locations determined?
How are pollock and the rest of the catch processed?
What information is retrieved from the trawl camera?
What is a bottom trawl and how is it different from a mid-water trawl?
We left Kodiak at 1 pm on July 22 heading southwest.
We had 8 hours of travel time before we would reach our first transect. But before we got too far away from Kodiak, we needed to practice the three drills for the safety of everyone. The fire drill and man overboard drill required me to report to the conference room and meet up with the rest of the science team. Patrick, the lead scientist, then reported that we were all accounted for. The crew had more complex tasks of deploying a small boat and retrieving “the man overboard”.
The other drill was the abandon ship drill. We are assigned to a lifeboat and I reported to my muster on the portside of the trawl deck with my survival suit, long sleeve shirt, hat and life preserver. We will have drills weekly at anytime.
For the last two days I have been becoming oriented to the ship and to my responsibilities to the science team. Jodi, a post doctorate from Juneau gave us a tour of the boat on the first day we arrived in Kodiak. I then practiced finding all of the key parts of the ship I will need to access. I now am confident that I can find my stateroom, the mess, laundry room, both exercise spaces, acoustics lab, and fish lab. For other sites, I wander around for a while until I locate it.
My first shift began at 4 pm on Monday. There are two shifts for scientists. Some work 4 am to 4 pm and the others work 4 pm to 4 am. I work the night shift. I never drink coffee but today I realized that I needed it. My shift includes scientists Paul, Jodi and Darin as well as a survey tech named Vince. We all share staterooms with people who work the opposite shift.
The ocean is very calm but most of us took Bonine (a seasickness medication) anyway to acclimate to the movement. Hopefully we will be adjusted to the motion before the seas get very rough if it does. The rocking of the boat does make one very sleepy.
Did You Know?
The requirements for joining the NOAA Corps include a bachelor’s degree in science, math or engineering and a 5 month program at the US Coast Guard Academy in New London, CT. This is Abby’s second cruise with the NOAA Corps. She has a bachelor’s degree in chemistry and just completed her NOAA officer basictraining.
Something to Think About:
What is a day in the life aboard the Oscar Dyson like?
Mission: Alaska Walleye Pollock Survey
Geographical Area: Gulf of Alaska
Date: July 18, 2013
My name is Julia Harvey and I currently teach biology and environmental science at South Eugene High School in Eugene, Oregon. Eugene is at the southern end of the Willamette Valley and just a short drive from the Pacific Ocean. I have taken many trips over the coastal range to Florence and the beautiful Oregon Coast.
And while the weather is not always cooperative, the ocean is always gorgeous. This last spring I took a group of students on a short marine discovery cruise out of Newport, where NOAA (National Oceanic and Atmospheric Administration) has based their Marine Operations Center for the Pacific.
It was my dream since 2nd grade to become a marine biologist. Mrs. Hellwege inspired me to learn more about the ocean as we studied marine mammals. My career path remained unchanged as I attended Occidental College and spent time on the college’s boat the Vantuna. I put my academic education on hold after graduating to serve in the Peace Corps. My passion for the sea continued while I was stationed in the South Pacific on an island in the Kingdom of Tonga. But as I became a teacher, I realized the perfect career would combine my love for biology and my new love of teaching. 22 years later, I now have to opportunity to revisit my childhood dream.
I learned about the NOAA Teacher at Sea program as I was taking an Oceanic Studies course. I decided to apply last October because I wished to connect my students directly with current research that is impacting our ocean environment. I also wanted to learn first hand how oceanic data was being collected since I have been out of the lab setting for quite some time. I was ecstatic when I learned in February that I was selected to sail. I am truly honored and appreciate the opportunity to involve my students in oceanic research and to present to them potential oceanic careers.
I will be sailing in the Gulf of Alaska aboard the Oscar Dyson and participating in a Walleye pollock fish population survey. Walleye pollock is the largest fisheries in the United States and one of the largest in the world. These fish become fish sticks, fish sandwiches and imitation crab. I am looking forward to learning more about the science involved in assessing a fish population. What makes fisheries healthy and sustainable?
My bags are packed with clothes, cameras, workouts, books and lots of enthusiasm. I am excited beyond description. I will be blogging several times a week and I hope you will continue to follow my journey at sea.
Latitude: N 26° 03.476′
Longitude: W 080° 20.920′
Weather Data from home
Wind Speed: 7.8 knots (9 mph)
Wind Direction: East
Wave Height: 2 ft
Surface Water Temperature: 28.9°C (84°F)
Air Temperature: 30°C (86 °F)
Barometric Pressure: 1016 millibars ( 1 atm)
Science and Technology Log:
Below are the numbers that Johanna (my fellow Teacher at Sea) put together at the end of our mission.
We completed 44 hauls in our leg of the survey and caught approximately 118,474 pollock. All of those pollock weighed a collective 24,979.92 kg (= 25 tons)! Last year’s official total allowable catch (called a quota) for all commercial fishermen in Alaska was 1.17 million tons!
So, we only caught 25 tons/ 1,170,000 tons = 0.00002 = 0.002% of the yearly catch in our study.
The estimated population of pollock in the Bering Sea is 10 million tons (10,000,000 T). This means we caught only 0.00025% of the entire pollock population!
So, as you can see, in the big picture, our sampling for scientific analysis is quite TINY!
Continuing with more cool pollock data…
We identified 7,276 males and 7,145 females (and 2,219 were left unsexed)
We measured 16,640 pollock lengths on the Ichthystick!
Pollock lengths ranged from 9cm to 74cm
We measured 260 lengths of non-pollock species (mostly jellyfish, pacific herring, and pacific cod)
We collected 1,029 otoliths for analysis
After two full days of travel including a long red-eye flight across country, I am back in Ft Lauderdale, Florida. I had the most incredible experience as a NOAA Teacher at Sea on the Oscar Dyson! The trip was absolutely amazing! Here are some parting shots taken on my last day in Dutch Harbor, Alaska.
In closing, I would like to thank a few people. The NOAA Corps officers and deck crew are wonderful and do a great job running a tight ship. I would like to thank them all for keeping me safe, warm, dry, and well fed while out at sea. They all made me feel right at home.
The NOAA scientists Taina, Kresimir, Rick and Darin did a fabulous job patiently explaining the science occurring onboard and I appreciate them letting me become a part of the team! I loved immersing myself back in the practice of real scientific inquiry and research!
I would like to thank the NOAA Teacher at Sea program for allowing me to take part in this incredible research experience for teachers! Teachers and students in my district are very excited to hear about my experiences and I look forward to continuing to share with them about NOAA Teacher at Sea! Sign me up, and I’d be happy to “set sail” with NOAA again.
Finally, I would like to thank my readers. I truly enjoyed sharing my experiences with you and hope that, through my blog, you were able to experience a bit of the Bering Sea with me.
Latitude: 53°54’41” N
Longitude: 166°30’61” E
Ship speed: 0 knots (0 mph) In Captains Bay at Dutch Harbor during calibration.
Weather Data from the Bridge
Wind Speed: 17 knots (19.5 mph)
Wind Direction: 184°
Wave Height: 1-2 ft
Surface Water Temperature: 10.2°C (50.4°F)
Air Temperature: 12.5°C (54.5°F)
Barometric Pressure: 1005.9 millibars (0.99 atm)
Science and Technology Log:
Imagine a time when fish surveys could be done through remote sensing, thus eliminating the need to catch fish via trawling to verify fish school composition, length, weight, and age data. During our “Leg 3” of the Alaska Pollock Acoustic Midwater Trawl Survey, we caught, sorted, sexed, and measured 25 tons of pollock! While this amounts to only 0.002% of the entire pollock quota and 0.00025% of the pollock population, wouldn’t it be nice if we could determine the pollock population without killing as many fish?
Introducing the “Cam-Trawl,” a camera-in-net technology that NOAA scientists Kresimir and Rick are developing to eventually reduce, if not eliminate, the need to collect biological specimens to verify acoustic data. Cam-Trawl consists of a pair of calibrated cameras slightly offset so the result is a stereo-camera.
The importance of setting up a stereo-camera is so you can use the slightly different pictures taken at the same time from each camera to calculate length of the fish in the pictures. Eventually, a computer system might use complex algorithms to count and measure length of the fish that pass by the camera. If the kinks are worked out, the trawl net would be deployed with the codend open, allowing fish to enter the net and flow past the camera to have their picture taken before swimming out of the open end of the net. Some trawls would still require keeping the codend closed to determine gender ratios and weights for extrapolation calculations; however, the use of Cam-Trawl would significantly reduce the amount of pollock that see the fish lab of the Oscar Dyson. On this leg of the survey, the NOAA scientists installed the Cam-Trawl in a couple of different locations along the trawl net to determine where it might work best.
Below are some photos taken by Cam-Trawl of fish inside the AWT trawl net. Remember, there are two cameras installed as a stereo-camera that create two images that are taken at slightly different angles. In the photos below, I only picked one of the two images to show. In the video that follows, you can see how scientists use BOTH photos to calculate the lengths of the fish captured on camera.
Another NOAA innovation using stereo cameras is called “Trigger-Cam.” Trigger-Cam is installed into a crab pot to allow it to sit on the ocean floor. For this type of camera deployment, the NOAA scientists removed the crab pot net so they would not catch anything except pictures.
The real innovation in the Trigger-Cam is the ability to only take pictures when fish are present. Deep-water fish, in general, do not see red light. The Trigger-Cam leverages this by using a red LED to check for the presence of fish. If the fish come close enough, white LEDs are used as the flash to capture the image by the cameras.
The beauty of this system is that it uses existing fishing gear that crab fishermen are familiar with, so it will be easily deployable. Another stroke of brilliance is that the entire device will cost less than $3,000. This includes the two cameras, lights, onboard computer, nickel-metal hydride batteries, and a pressure housing capable of withstanding pressures of up to 50 atmospheres (500 meters) as tested on the Oscar Dyson! Here is a short animated PowerPoint that explains how Trigger-Cam works. Enjoy!
Here are a couple of picture captured by the Trigger-Cam during trials!
While these pictures were captured during tests in Dutch Harbor, they do provide proof-of-concept in this design. With a cheap, easily deployable and retrievable stereo-camera system that utilized fishing gear familiar to most deck hands, Trigger-Cams might contribute to NOAA’s future technology to passively survey fish populations.
A little fun at sea! We needed to do one last CTD (Conductivity, Temperature, Depth), and decided to lower the CTD over deep water down to 500 meters (1,640.42 ft)! Pressures increases 1 atmosphere for every 10 meters in depth. At 500 meters, the pressure is at 50 atmospheres!!! We wondered what would happen if… we took styrofoam cups down to that depth. We all decorated our cups and put them in a net mesh bag before they took the plunge. Here is a picture showing what 50 atmospheres of pressure will do to a styrofoam cup!
We missed the Summer Olympics while out on the Bering Sea. T-T We did get in the Olympic spirit and had a race or two. Here is a little video in the spirit of the Olympics…
All for now… We are back in Captains Bay, Dutch Harbor, but are calibrating the hydroacoustic equipment at anchor. Calibration involves suspending a solid copper sphere below the ship while the NOAA scientists check and fine-tune the different transducers. This process will take about 7 hours! We have been out at sea for 3 weeks, are currently surrounded by land, but must wait patiently to finish this last and very important scientific task. If the calibration is off, it could skew the data and result in an inaccurate population estimation and quotas that may not be sustainable! This Landlubber can’t wait to have his feet back on terra firma. The thought of swimming crossed my mind, but I think I’ll wait. Then we will see if I get Land Sickness from being out at sea for so long…
Latitude: 60°25’90” N
Longitude: 177°28’76” W
Ship speed: 3 knots (3.45 mph)
Weather Data from the Bridge
Wind Speed: 5 knots (5.75 mph)
Wind Direction: 45°
Wave Height: 2-4 ft with a 2 ft swell
Surface Water Temperature: 8.6°C (47.5 °F)
Air Temperature: 8°C (46.4 °F)
Barometric Pressure: 1019 millibars (1 atm)
Science and Technology Log:
In my last blog, we learned about how the scientists onboard the Oscar Dyson use some very sophisticated echo-location SONAR equipment to survey the Walleye pollock population.
Can the Walleye pollock hear the “pings” from the SONAR?
No. Unlike in the movies like “The Hunt for Red October” where submarines are using sound within the human audible range to “ping” their targets, the SONAR onboard the Oscar Dyson operates at frequencies higher than both the human and fish range of hearing. The frequency used for most data collection is 38 kHz. Human hearing ranges from 20 Hz to 20 kHz. Walleye pollock can hear up to 900 Hz. So, the pollock cannot hear the SONAR used to locate them…
Can the Walleye pollock hear the ship coming?
Normally, YES! Fish easily hear the low frequency noises emitted from ships.
If you are operating a research vessel trying to get an accurate estimate on how many fish are in a population, and those fish are avoiding you because they hear you coming, you will end up with artificially low populations estimates! The International Council for the Exploration of the Seas (ICES) established noise limits for research vessels that must be met in order to monitor fish populations without affecting their behavior. Fish normally react to a threat by diving, and that reduces their reflectivity or target strength, which reduces the total amount of backscatter and results in lower population estimates (see my last blog).
That is why NOAA has invested in noise-reducing technology for their fish survey fleet. The Oscar Dyson was the first of five ships build with noise-reducing technology. These high-tech ships have numerous strategies for reducing noise in the range that fish might hear.
There are two main sources of engine noise onboard a ship: machinery noise and propeller noise.
The best acoustic ship designs are going to address the following:
1) Address hydrodynamics with unique hull and propeller design.
2) Use inherently quiet equipment and choose rotating rather than reciprocating equipment.
3) Use dynamically stiff foundations for all equipment (vibration isolation).
4) Place noisier equipment toward the centerline of the ship.
5) Use double-hulls or place tanks (ballast and fuel tanks) outboard of the engine room to help isolate engine noise.
6) Use diesel electric motors (diesel motors operate as generators while electric motors run the driveshaft.
The U.S. Navy designed the Oscar Dyson’s hull and propeller for noise quieting. This propeller is designed to eliminate cavitation at or above the 11 knot survey speed. Not only does cavitation create noise, it can damage the propeller blades.
The Oscar Dyson’s hull has three distinguishing characteristics which increase its hydrodynamics and reduce noise by eliminating bubble sweep-down along the hull. The Oscar Dyson has no bulbous bow, has a raked keel line that descends bow to stern, and has streamlined hydrodynamic flow to the propeller.
To reduce a ship’s noise in the water, it is absolutely crucial to control vibration. The Oscar Dyson has four Caterpillar diesel gensets installed on double-stage vibration isolation systems. In fact, any reciprocating equipment onboard the Oscar Dyson is installed on a double-stage vibration isolation system using elastomeric marine-grade mounts.
Since the diesel engines are mounted on vibration isolation stages, it is necessary to also incorporate flexible couplings for all pipes and hoses connecting to these engines.
Any equipment with rotating parts is isolated with a single-stage vibration system. This includes equipment like the HVAC, the electric generators for the hydraulic pumps, and the fuel centrifuges that remove any water and/or particles from the fuel before the fuel is pumped to the diesel generators.
Low Noise Equipment:
The only equipment that does not use vibration isolation stages are the two Italian-made ASIRobicon electric motors that are mounted in line with the prop shaft. Both are hard-mounted directly to the ship because they are inherently low-noise motors. This is one of the benefits of using a diesel-electric hybrid system. The diesel motors can be isolated in the center of the ship, near the centerline and away from the stern. The electric motors can be located wherever they are needed since they are low noise.
Even the propeller shaft bearings are special water-lubricated bearings chosen because they have a low coefficient of friction and superior hydrodynamic performance at lower shaft speeds resulting in very quiet operation. They use water as a lubricant instead of oil so there is a zero risk of any oil pollution from the stern tube.
Acoustic Insulation and Damping Tiles:
The Oscar Dyson uses an acoustic insulation on the perimeter of the engine room and other noisy spaces. This insulation has a base material of either fiberglass or mineral wool. The middle layer is made of a high transmission loss material of limp mass such as leaded vinyl.
The Oscar Dyson also has 16 tons of damping tiles applied to the hull and bulkheads to reduce noise.
All of these noise-reducing efforts results in a fully ICES compliant research vessel able to survey fish and marine mammal populations with minimal disturbance. This will help set new baselines for population estimates nationally and internationally.
As you can see from the graph above, The Oscar Dyson is much quieter than the Miller Freeman, the ship that it is replacing. You can see the differences in the hull design from the picture below.
Next blog, I will write about new, cutting edge technology that might reduce the need for biological trawling to verify species.
Special thanks to Chief Marine Engineer Brent Jones for the tour of the engineering deck and engine room, and for the conversations explaining some of the technology that keeps the Oscar Dyson going.
I found out drills aboard ships are serious business! Unlike a fire drill at school where students meander across the street and wait for an “all clear” bell to send them meandering back to class, fire drills on a ship are carefully executed scenarios where all crew members perform very specific tasks. When out at sea, you cannot call the fire department to rescue you and put out a fire. The crew must be self-reliant and trained to address any emergency that arises. When we had a fire drill, I received permission from Commanding Officer Boland to leave my post (after I checked in) and watch as the crew moved through the ship to locate and isolate the fire. They even used a canister of simulated smoke to reduce visibility in the halls similar to what would be experienced in a real fire!
Late last night, we finished running our transects! Our last trawl on transect was a bottom trawl which brought up some crazy creatures! Here are a couple of photos of some of the critters we found.
Next blog will probably be my last from Alaska. T-T
Latitude: 60°55’68” N
Longitude: 179°34’49” E
Ship speed: 11 knots (12.7 mph)
Weather Data from the Bridge
Wind Speed: 10 knots (11.5 mph)
Wind Direction: 300°
Wave Height: 2-4 ft with a 4-6 ft swell
Surface Water Temperature: 8.7°C (47.6°F)
Air Temperature: 8°C (46.4°F)
Barometric Pressure: 1013 millibars (1 atm)
Science and Technology Log
Previously, we learned how the biological trawl data onboard the NOAA Research Vessel Oscar Dyson are collected and analyzed to help calculate biomass of the entire Bering Sea Walleye pollock population. Last blog, I mentioned that the scientific method for estimating the total pollock biomass is not complete without acoustics data, more specifically hydroacoustics! In fact, hydroacoustic data are the real key to estimating how many pollock are in the Bering Sea! That is why our mission is called the Alaskan Pollock Midwater ACOUSTIC-trawl Survey.
The Oscar Dyson is using hydroacoustics to collect data on the schools of fish in the water below us, but we do not know the composition of those schools. Hydroacoustics give us a proxy for the quantity of fish, but we need a closer look. The trawl data provide a sample from each aggregation of schools and allow the NOAA scientists that closer look. The trawl data explain the composition of each school by age, gender and species distribution. Basically, the trawl data verifies and validates the hydroacoustic data. The hydroacoustics data collected over the entire Bering Sea in systematic transects combined with the validating biological data from the numerous individual trawls give scientists a very good estimate for the entire Walleye pollock population in the Bering Sea.
So what is hydroacoustics and how does it work???
Hydroacoustics (“hydro” = water, “acoustics” = sound) is the field of study that deals with underwater sound. Remember, sound is a form of energy that travels in pressure waves. Sound travels roughly 4.3 times faster in water than in air (depending on temperature and salinity of the water). Here is a link with an interactive animation comparing the speed of sound in water, air, and steel! This change in speed will become very important later… keep reading!
Lower sound frequencies travel farther. This is how humpback whales can communicate over great distances with their whale songs! Click on whale songs to hear one!
Whales are not the only aquatic organisms to use sound! Much like dolphins use sound to echo-locate, people use technology to “see” under water using sound energy. We call this technology SONAR (Sound Navigation And Ranging).
On a typical recreational watercraft, this technology can be found in the form of a “fish-finder.”
In commercial fishing, this technology is used in much the same way, just on a larger scale. Here is an animation showing a commercial trawler using SONAR to locate fish.
The Oscar Dyson has a much more powerful, extremely sensitive, carefully calibrated, scientific version of what many people have on their bass boats. These are mounted on the pod, which is on the bottom of the centerboard, the lowest part of the ship. The Oscar Dyson has an entire suite of SONAR instrumentation including the five SIMRAD EK60 transducers located on the bottom of the centerboard that operate at different Khertz, the SIMRAD ME70 multibeam transducer located on the hull, and a pair of SIMRAD ITI transducers on the trailing edge of the centerboard (one pointed toward the starboard side, the other toward port).
This “fish-finder” technology works by emitting a sound wave at a particular frequency and waiting for the sound wave to bounce back (the echo) at the same frequency. The time between sending and receiving the sound wave determines how far away an object is, whether it be the bottom or fish. When the sound waves return from a school of fish, the strength of the returning echo helps determine the fish density (how many fish are there).
Another piece of the puzzle… how reflective an individual fish is to sound waves. This is called target strength. Each fish reflects sound energy sent from the transducers, but why? For fish, we rely on the swim bladder, the organ that fish use to stay buoyant in the water column. Since it is filled with air, it reflects sound very well. When the sound energy goes from one medium to another, there is a stronger reflection of that sound energy. The bigger the fish, the bigger the swim bladder; the bigger the swim bladder, the more sound is reflected and received by the transducer. We call this backscatter, or target strength, and use it to estimate the size of the fish we are detecting. This is why fish that have air-filled swim bladders show up nicely on hydroacoustic data while fish that lack swim bladders (like sharks), or that have oil or wax filled swim bladders (like Orange Roughy) have weak signals.
Target strength is how we determine how dense the fish are in a particular school. Scientists take the backscatter that we measure from the transducers and divide that by the target strength for an individual and that gives you the number of individuals that must be there to produce that amount of backscatter. 100 fish produce 100x more echo than a single fish. We extrapolate this information to all the area of the Bering Sea to estimate the pollock population.
So the goal is to measure the hydroacoustic density along each transect and extrapolate that data to represent the entire survey area between transects (the area not sampled because the Oscar Dyson can’t cover every square meter of the Bering Sea). When you combine the hydroacoustic data for all of the 30 transects (a total of ~5,000 nautical miles in an area of 100,000 square nautical miles) and the lengths collected in the biological trawl data, you can convert the length data into target strength data to create a distribution of target strengths and find the average target strength for the population. In doing so, you get a complete picture of the Walleye pollock population in the Bering Sea.
But there’s more!!! Scientists ALSO use hydroacoustic data when trawling to determine if they have caught a large enough sample size to collect fish length data to validate their target strength data. If you recall reading my first blog from sea that taught about the parts of the net, I wrote about and had a drawing of the “kite” on which the “turtle” was attached. The “turtle” is a SIMRAD FS70 trawl SONAR. It has a downward facing transponder that shows a digital “picture” of the size of the net opening. You can also see individual fish and/or schools of fish enter the net by watching this display. Since the scientists only need about 300 fish for a statistically significant sample, they watch this screen carefully so that they do not take more fish than they need. When the lead scientist thinks there are enough fish in the net, she gives the request to the Officer on Deck to “haul back.” Unlike commercial trawlers, a typical trawl on the Oscar Dyson only lasts 25 minutes. Sometimes, we are only officially fishing for 5 minutes if we pull through a large school.
What are the data telling us?
The Walleye pollock data suggest that the population is currently stable; however, there is some evidence of pollock in waters that have traditionally been north of their uppermost documented population range. Are warmer waters due to climate change to blame for this possible shift? Here is an interesting article that addresses this issue and raises several other trends regarding pollock population response to changes in food source and predation due to climate change. Click on the picture to open the article!
The economic and ecological implications of a shifting pollock population range are a bit unsettling. Fish do not know political boundaries. As the pollock population range possibly shifts north, more of that range will lie within Russian waters than in previous years. This may hurt the U.S. commercial fishing industry as they settle for less of a resource that was once abundant. Since quotas are set based on last year’s numbers, there is a time lag which may result in overfishing in U.S. waters that might lead to a collapse in the Alaskan Walleye pollock fishing industry. The U.S. has invested a tremendous amount of research into maintaining a sustainable pollock fishery. Other countries may be responding to a variety of factors in which sustainability is just one when they are managing pollock stocks and setting catch quotas. Since pollock is a trans-boundary stock, this could lead to greater uncertainty in management of the entire population if pollock increasingly colonize more northern Bering Sea waters as influenced by climate change.
Food for thought…
Next blog, we will learn about cutting edge technology that may eventually make hauling back fish and collecting biological fish data on board the acoustic survey missions obsolete.
It’s tomorrow, TODAY! This morning at 6am Alaska Time, we crossed the International Date Line (IDL). The IDL is at 180° longitude. General Vessel Assistant Brian Kibler and I went out to the bow of the ship so we would be the first onboard to cross the line!
Over the next two days, our transects take us back and forth over the IDL 3 more times. Fortunately, onboard our Oscar Dyson time warp machine we simply observe the Alaska Time Zone (the time zone from our port of call). With everyone onboard operating different shifts, and with 24/7 operations, it would be quite confusing if we kept changing our clocks to observe the local time zone.
Mariners who cross the IDL when at sea are inducted into the “Order of the Golden Dragon” and receive a certificate with the details of this momentous crossing. There are several other notorious crossing that receive special recognition. They are:
▪ The Order of the Blue Nose for sailors who have crossed the Arctic Circle.
▪ The Order of the Red Nose for sailors who have crossed the Antarctic Circle.
▪ The Order of the Ditch for sailors who have passed through the Panama Canal.
▪ The Order of the Rock for sailors who have transited the Strait of Gibraltar.
▪ The Safari to Suez for sailors who have passed through the Suez Canal.
▪ The Order of the Shellback for sailors who have crossed the Equator.
▪ The Golden Shellback for sailors who have crossed the point where the Equator crosses the International Date Line.
▪ The Emerald Shellback or Royal Diamond Shellback for sailors who cross at 0 degrees off the coast of West Africa (where the Equator crosses the Prime Meridian)
▪ The Realm of the Czars for sailors who crossed into the Black Sea.
▪ The Order of Magellan for sailors who circumnavigated the earth.
▪ The Order of the Lakes for sailors who have sailed on all five Great Lakes.
Latitude: 61°12’61” N
Longitude: 178°27’175″ W
Ship speed: 11.6 knots (13.3 mph)
Weather Data from the Bridge
Wind Speed: 11 knots (12.7 mph)
Wind Direction: 193°
Wave Height: 2-4 ft (0.6 – 1.2 m)
Surface Water Temperature: 8.3°C ( 47°F)
Air Temperature: 8.5°C (47.3°F)
Barometric Pressure: 999.98 millibars (0.99 atm)
Science and Technology Log
At the end of last blog, I asked the question, “What do you do with all these fish data?”
The easy answer is… try and determine how many fish are in the sea. That way, you can establish sustainable fishing limits. But there is a little more to the story…
Historically, all fisheries data were based on length. It is a lot easier to measure the length of a fish than to accurately determine its weight on a ship at sea. To accurately measure weight on a ship, you have to have special scales that account for the changes in weight due to the up and down motion of the ship. Similar to riding a roller coaster, at the crest of a wave (or top of a hill on a roller coaster), the fish would appear to weigh less as it experiences less gravitational force. At the trough of a wave (or bottom of a hill on a roller coaster), the fish would experience more gravitational force and appear to weigh more. Motion compensating scales are a more recent invention, so, historically, it was easier to just measure lengths.
For fisheries management purposes, however, you want to be able to determine the mass of each fish in your sample and inevitably the biomass of the entire fishery in order to decide on quotas to determine a sustainable fishing rate. So, you need to be able to use length data to estimate mass. Here is where science and math come to the rescue! By taking a random sample that is large enough to be statistically significant, and by using the actual length and weight data from that sample, you can create a model to represent the entire population. In doing so, you can use the model for estimating weights even if all you know is the lengths of the fish that you sample. Then you can extrapolate that data (using the analysis of your acoustic data – more on this later) to determine the entire size of the pollock biomass in the Bering Sea.
How do they do that? First, you analyze and plot the actual lengths vs. weights of your random sample and your result is a scatter-plot diagram that appears to be an exponential curve.
Then you create a linear model by log-transforming the data. This gives you a straight line.
Next, you back-transform the data into linear space (instead of log space) and you will have created a model for estimating weight of pollock if all you know are the lengths of the fish. This is close to a cubic expansion which makes sense because you are going from a one-dimensional measurement (length) to a 3-dimensional measurement (volume).
Scientists can now use this line to predict weights from all of their fish samples and then extrapolate to determine the entire biomass of Walleye pollock population in the Bering Sea (when combined with acoustic data… coming up in the next blog!) when the majority of the data collected is only fish lengths.
Another interesting question… How does length change with age? Fish get bigger as they get older, all the way until they die, which is different from mammals and birds. However, some individual fish grow faster than others, so the relationship between age and length gets a little complicated. How do you determine the age distribution of an entire population when all you are collecting are lengths?
Just like weight, you can determine the age from a subset of fish and apply your results to the rest. This works great with young fish that are one year old. The problem is… once you get beyond a one-year-old fish, using lengths alone to determine age becomes a little sketchy. Different fish may have had a better life than others (environmental/ecological effects) and had plenty to eat, great growing conditions, etc and be big for their age relative to the rest of the population. Some may have had less to eat and/or unfavorable conditions such as high parasite loads leading them to be smaller… There are also other things to consider such as genetics that affect length and growth rate of individuals. Here is where the collection of otoliths becomes important. By collecting the otoliths with the lengths, weights, and gender data, the scientists can look at the age distributions within the population. The graph below shows that if a pollock is 15 cm long, it is clearly a 1 year old fish. If a pollock is 30 cm long, it might be a 2 year old, a 3 year old, or a 4 year old fish, but about 90% of fish at this length will be 3 years old. If a fish is 55 cm long, it could be anywhere from 6 to 10+ years old!
Collection of otoliths is the only way to accurately determine the age of the fish in the random sample and be able to extrapolate that data to determine the estimated age of all the pollock in the fishery. Here is a photo comparing otolith size of Walleye pollock with their lengths.
If we wanted to find out exactly how old each of these fish were, we would need to break the otoliths in half to look at a cross section. Below is what a prepared otolith looks like (courtesy of Alaska Fisheries Science Center). You can try counting rings yourself at their interactive otolith activity found here.
All of these data go into a much more complicated model (including the acoustic-trawl survey walleye pollock population estimates) to accurately estimate the total size of the fishery and set the quotas for the pollock fishing industry so that the fishery is maintained in a sustainable manner.
Next blog, we will learn about how the various ways acoustic data fit into this equation to create the pollock fishery model!
Ok, so here is a long overdue look at the NOAA Ship Oscar Dyson that I am calling home for three weeks. I was pleasantly surprised when I saw my state room. It is bigger than I thought it would be and came with its own bathroom. I was also pleasantly surprised to learn I would be sharing my state room with Kresimir Williams, one of the NOAA scientists and an old college friend of mine! Here is a picture of our room.
The room has a set of bunk beds. Thankfully, my bed is on the bottom. I do not know how I would have gotten in and out of bed in the rough seas we had over the last couple of days. If I do fall out of bed, at least I will not have far to fall. Last year, the ship rocked so hard in rough seas that one of the scientists fell head first out of the top bunk! The room also had two lockers that serve as closets, a desk and chair, and our immersion suits (the red gumby suits). The bathroom is small and the shower is tiny! Notice the handles on the wall. These are really handy when trying to shower in rough seas!
Next, we have the Galley or Mess Hall. This is where we have all of our meals prepared by Tim and Adam. Notice that all of the chairs have tennis balls on the legs and that each chair has a bungee cord securing it to the floor! There are also bungee cords over the plates and bowls. Everything has to be secured for rough seas.
The Mess Hall also has a salad bar, cereal bar, sandwich fixings, soup, snacks like cookies, and ice cream available 24 hours a day. No one on board is going hungry. The food has been excellent! We have had steaks, ribs, hamburgers and fish that Tim has grilled right out on deck. Here is a picture of my “surf and turf” with a double-baked potato.
Most of my work here on board (other than processing fish) has been in the acoustics lab, also known as “The Cave” since it has no windows. This is where the NOAA scientists are collecting acoustic data on the schools of fish and comparing the acoustic data with the biological samples we process in the fish lab.
I also spend some time up on the Bridge. From the Bridge, you can see 10 to 12+ nautical miles on a clear day. This morning, we saw a couple of humpback whales blowing (surfacing to breathe) about 1/4 mile off our starboard side! A couple of days ago (before the weather turned foul), we spotted an American trawler.
Today, we got close enough to see the Russian coastline! Here is a picture of a small tanker ship with the Russian coastline in the background!
Here are some pictures of the helm and some of the technology we have onboard to help navigate the ship.
I have also spent some time in the lounge. This is where you can go to watch movies, play darts (yea, right! on a ship in rough weather???), or just relax. The couch and chairs are so very comfy!
When you have 30 people on board and in close quarters, you better have a place to do laundry! Here is a picture of our very own laundromat.
All for now. Next time, I will share more about life at sea!
NOAA Teacher at Sea Johanna Mendillo Aboard NOAA Ship Oscar Dyson July 23 – August 10, 2012
Mission: Pollock Survey Geographical area of the cruise: Bering Sea Date: Wednesday, August 1, 2012
Location Data from the Bridge: Latitude: 62○ 18’ N
Longitude: 178○ 51’ W
Ship speed: 2.5 knots (2.9 mph)
Weather Data from the Bridge:
Air temperature: 9.5○C (49.1ºF)
Surface water temperature: 8.5○C (47.3ºF)
Wind speed: 9.1 knots (10.5 mph)
Wind direction: 270○T
Barometric pressure: 1001 millibar (0.99 atm)
Science and Technology Log:
In the last few days, we have crossed into the Russian Exclusive Economic Zone, sampled, and are now back on the U.S. side! Unfortunately, students, there was no way for my passport to get stamped. There was no formal ceremony, and we will cross back and forth many times in the next two weeks as we do our science transects, collecting Pollock, but the science team took a moment to celebrate— and I snapped a quick picture of the computer screen.
I would now like to introduce you to one of the most simple and valuable tools we use on board to measure a sample of Pollock- the Ichthystick.
First, some background. Each day we “go fishing” 2-4 times with our mid-water and bottom trawls. “Trawling” simply means dragging a large net through the water to collect fish (and you will learn more about the different types of nets we use quite soon). After the trawl, we bring the net back on board and see what we have caught!
There are many types of data we collect from each catch- first and foremost, the total weight of the catch and the numbers and masses of any species we catch in addition to pollock. So far, we have collected salmon, herring, cod, lumpsuckers, rock sole, arrowtooth flounder, Greenland turbot, and jellyfish on my shifts! Our focus, though, of course, is pollock. For pollock-specific data, we keep a sub-sample of the catch, usually 300-500 fish, for further analysis, and we release the rest back into the ocean.
From this sub-sample, I help the scientists collect gender and length data. As I mentioned in my last post, we also collect otoliths from the sub-samples so that the age structure of the population can be studied back in Seattle. The most straightforward and obvious data, though, is simply measuring the length of the fish, which takes us back to the wonderful contraption known as the Ichthystick!
Now, scientists cannot determines the age of a pollock simply from measuring its length- there are many factors that determine how fast a fish can grow, such as access to food, space, its overall health, environmental conditions, etc. But, by collecting length data and combining it with age data from otoliths, scientists can begin to see the length ranges at each age class and the overall “big picture” for the population emerges.
And again, once the age structure and population size of pollock in the Bering Sea are determined for a certain year, management decisions can be made, commercial fish quotas are set for the upcoming fishing season, and there will still be a suitable population of fish left in the ocean to reproduce and keep the stocks at sustainable levels for upcoming years.
So, it clearly does not make much sense to measure pollock with a ruler, paper, and pencil. To measure hundreds of fish at a time, the NOAA team has developed a simple yet ingenious measuring tool, powered by magnets, and transmitted electronically back to their computers for easy analysis- the Ichthystick!
The Ichthystick may simply look like a large ruler, but it consists of a sensor and electronic processing board mounted in a protective (& waterproof!) container. Inside, the sensor processes, formats and transmits the measurement values of each fish to an external computer that collects and stores the data.
Interestingly, the board works with magnets and makes use of the property of magnetostriction.
With magnetostriction, magnetic materials change shape when exposed to a magnetic field. Magnetostrictive sensors can use this property to measure distances by calculating the “time of flight” for a sonic pulse generated in a magnetic filament when a measurement magnet is placed close to the sensor. Here, in the picture, I am placing the fish along the sensor and holding the measurement magnet in my right hand.
To determine the distance to the measurement magnet, the elapsed time between when I touch the magnet to the board to generate the ultrasonic pulse and when the pulse is detected by the sensor is recorded– and that time is converted to a distance (using the speed of sound in that material), which is equal to the fish’s length!
Now, the “measurement magnet” is referred to as the “stylus”, and it is a little white plastic piece, the size of a magic marker cap, which contains the magnet embedded into the bottom. You simply strap the stylus onto your index finger with velcro (so that the north pole of the magnet is facing down toward the sensor) and are ready to begin measuring! The magnet inside is a small neodymium magnet, chosen because it has a very strong magnetic field. Each time a measurement is recorded, a chime sounds, and I know I can go on to measuring my next fish! At this point, I have measured a few thousand fish!
Let’s continue our tour aboard the Oscar Dyson! I think it is fair to say that scientific research makes one hungry! I have enjoyed meeting Tim and Adam, the stewards (chefs) onboard the Dyson, devouring their delicious meals, and spending time talking with the officers and crew in the galley (kitchen) and mess (dining hall). As you can see from my picture, the first thing you notice are the tennis balls on the bottoms of the chairs! Why do you think they are there?
As in most things related to ship design, planning for rough seas is paramount! So, in addition to tennis balls, which stop the chairs from sliding around, there are bungee cords that attach the chairs to the floor. The dishes are also strapped down and most items are in boxes, bins, or behind closed doors. But do not let that fool you— there is a LOT of food in there! I have enjoyed many a midnight snack- fruit, yogurt, ice cream bars, cereal bars, cookies, and soup to name just a few. In addition, there is a salad bar and a selection of leftover dinner items available to reheat each night. Since I am on the 4pm-4am shift, I have been missing breakfast, and I have been told I must have at least one hot cooked-to-order meal before I depart!
I was a little surprised to see a mini-Starbucks on board too! It is quite a setup, complete with pictures and directions on how to make each concoction:
Dennis, one of the Survey Technicians who works on the overnight shift with me, promised to make me a hazelnut latte if I could correctly predict the number of pollock in a trawl, Price-Is-Right style. I finally won a few nights ago….
Interestingly, there are no mechanisms in place to help the stewards cook in rough seas, but Adam assured me that he has never had a dinner for thirty slide off the grill and onto the floor! Adam has been working in the NOAA fleet for over 10 yrs., including 7 yrs on the Miller Freeman, the precursor to the Oscar Dyson. He has been onboard the Dyson for almost a year. Tim has just joined the Dyson on this cruise and was previously in our home state— aboard the Delaware out of Woods Hole, Massachusetts! Before joining NOAA, he worked on several supply ships that sailed across the world. Each has been quite friendly and helpful as I learn to navigate my way around both the ship and my new schedule. One of our frequent conversations is menu planning and the all-important-dessert on the schedule for each night. So far, I have enjoyed apple cobbler, pineapple upside down cake, snickers cake, carrot cake, brownie sundaes, oatmeal raisin cookies, and… Boston cream pie!
One last Q: How many dozens of eggs do you think Tim and Adam will go through on our 19-day cruise with 30 people on board? Write your guess in the comment section and I will announce the answer in my next post…
Latitude: N 61°39’29”
Longitude: W 117°55’90”
Ship speed: 11.7 knots (13.5mph)
Weather Data from the Bridge
Wind Speed: 26 knots (30mph)
Wind Direction: 044°
Wave Height: 4 meters (12 ft)
Surface Water Temperature: 8.2°C ( 46.8°F)
Air Temperature: 7.4°C (45°F)
Barometric Pressure: 994 millibar (0.98 atm)
Science and Technology Log:
Last blog, we learned about the different trawl nets and how the NOAA scientists are comparing those nets while conducting the mid-water acoustic pollock survey. We left off with the fish being released from the codend onto the lift table and entering the fish lab. Here is where the biological data is collected.
The fish lab is where the catch is sorted, weighed, counted, measured, sexed, and biological samples such as the otoliths, or earbones, are taken (more about otoliths later in this post). First, the fish come down a conveyor belt where they are sorted by species (see video above). Typically, the most numerous species (in our case pollock) stay on the conveyor and any other species (jellyfish and/or herring, but sometimes a salmon or two, or maybe even something unique like a lumpsucker!), are put into separate baskets to weigh and include in the inventory count. In the commercial fishing industry, these species would be considered bycatch, but since we are doing an inventory survey, we document all species caught. Here are some pictures of others species caught and included in the midwater survey.
The goal of each trawl is to randomly select a sample of 300 pollock to measure as a good representation of the population (remember your statistics! Larger sample sizes will give you a better approximation of the real population). If more than 300 pollock are caught, the remainder are weighed in baskets and quickly sent back to sea. All of the catch is weighed so the scientists can use the length and gender data taken from the sample to extrapolate for the entire catch. This data is combined with the acoustics data to estimate the size of the entire fishery (more on acoustic data in a future post). Weights are entered via touch screen into a program (Catch Logger for Acoustic Midwater Surveys – CLAMS) developed by the NOAA scientists onboard.
The 300 pollock are sexed to determine the male/female ratio of this randomly selected portion of the population. Gender is determined by making an incision along the ventral side from posterior to anterior beginning near the vent. This exposes the internal organs so that either ovaries or testes can be seen. Sometimes determining gender is tricky since the gonads look very different as fish pass through pre-spawning, spawning, or post-spawning stages. When we determine gender, the fish are put into two separate hoppers, the one for females is labeled “Sheilas” and the hopper for males is labeled “Blokes.”
We use an Ichthystick to then measure the males and females separately to collect length data for this randomly selected sample. Designed by NOAA Scientists Rick and Kresimir, the Ichthystick very quickly measures lengths by using a magnet placed at the fork of the fish’s tail (when measuring fork-length). This sends a signal to the computer to record the individual fish’s length data immediately into a spreadsheet and the software creates a population length distribution histogram in real-time as you enter data.
A randomly selected subset of 40 pollock get individually weighed, length measured, sexed, evaluated for gonadal maturity and have the otoliths removed. Otoliths (oto = ear, lithos = bone) are calciferous bony structures in the fish’s inner ear. These are used to determine age when examined via cross-section under a dissecting scope. The number of rings corresponds to the age of the pollock, similar to rings seen in trees. The otoliths are taken by holding the fish at the operculum and making an incision across the top of the head to expose the brain and utricle of the inner ear. The otolith is found inside the utricle. Forceps are used to extract the otoliths, which are then washed and put in individual bar-coded vials with glycerol-thymol solution to preserve them for analysis back at the Alaska Fisheries Science Center.
Watch this short video to see what the entire process of data collection looks like.
So… why collect all of this data? How is this data analyzed and used? Stay tuned to my next blog!
Well, I can officially say… the honeymoon is over. The Bering Sea had been so extremely kind to us with several days of great weather while we had a high pressure system over us. We enjoyed spectacular sunrises and sunsets, cloudless days and calm seas.
Now… we have a low pressure system on top of us. Last night, we experienced 35 knot winds and 12 foot seas. I have spent a lot of time in my room in the past 24 hours… Late this morning, the sun came out and the winds calmed down, but the barometric pressure was still very low (around 990 mbars) which basically meant we were in the center of the low pressure system (similar to the eye of a hurricane, but not as strong… thank goodness!). We had a few hours relief, but we are back to pounding through the waves as the wind picks back up. It will be another long and sleepless night for this landlubber…
On a positive note, we did see two Laysan Albatrosses (Phoebastria immutabilis) from the Bridge as the winds began to kick up. They seemed to really enjoy the high winds as they soared effortlessly around the ship. The Officer on Deck (OOD) also said he saw a humpback breaching, but by the time I got up to the Bridge, it had moved on…
Next blog, I will share pictures of my room, the galley, “the cave,” the Bridge, etc. Right now, I am just trying to hold on to my mattress and my stomach…
Ship speed: 3.8 knots (4.4 mph) currently fishing
Weather Data from the Bridge
Wind Speed: 6.9 knots (7.9 mph)
Wind Direction: 30°T
Wave Height: 2ft with 2-4ft swells
Surface Water Temperature: 8.7°C ( 47.7°F)
Air Temperature: 7.9°C ( 46.2°F)
Barometric pressure: 1005.8 millibar (0.99 atm)
Science and Technology Log:
Since the main goal of this voyage is the acoustic-trawl survey of the mid-water portion of the Alaskan pollock population, I thought I would start by telling you how we go fishing to catch pollock! This isn’t the type of fishing I’m used to… Alaskan pollock is a semi-demersal species, which means it inhabits from the middle of the water column (mid-water) downward to the seafloor. This mid-water survey is typically carried out once every two years. Another NOAA Fisheries survey, the bottom trawl survey, surveys the bottom-dwelling or demersal portion of the pollock population every year. I will begin by describing how we are fishing for pollock on this acoustic-trawl survey.
The Oscar Dyson carries two different types of trawling nets for capturing fish as part of the mid-water survey, the AWT (Aleutian Wing Trawl which is a mid-water trawl net) and the 83-112 (a bottom-trawl net that is named for the length of its 83 foot long head rope that is at the top of the mouth of the net and the 112 foot long weighted foot rope at the bottom of the mouth of the net). One of the research projects on board the Oscar Dyson is a feasibility study that involves a comparison of the AWT and using the 83-112 bottom-trawl net as if it were a mid-water net. The 83-112 is much smaller than the AWT, so there is concern with the fish avoiding this net and thus causing a reduction in catch. While the bottom trawl survey acquires good information on the bottom-dwelling pollock using the 83-112 bottom trawl, if they also used this net to sample in mid-water they could help “fill in” estimates of mid-water dwelling pollock in years when the acoustic mid-water trawl survey does not occur.
When the net is deployed from the ship, the first part of the net in the water is called the cod end. This is where the caught fish end up. The mesh size of the net gets smaller and smaller until the mesh size at the cod end is only ½ inch (The mesh size at the mouth of the net is over 3 meters!).
The AWT is also outfitted with a Cam-Trawl, which is the next major part that hits the water. This is a pair of cameras that help scientists identify and measure the fish that are caught in the net. Eventually, this technology might be used to allow scientists to gather data on fish biomass without having to actually collect any fish (more on this technology later). This piece of equipment has to be “sewn” into the side of the net each time the crew is instructed to deploy the AWT. The crew uses a special type of knot called a “zipper” knot, which allows them to untie the entire length of knots with one pull on the end much like yarn from a sweater comes unraveled.
Along the head rope, there is a piece of net called the “kite” where a series of sensors are attached to help the scientists gather data about the depth of the net, the shape of the net underwater, how large the net opening is, determine if the net is tangled, how far the net is off the bottom, and see an acoustic signal if fish are actually going into the net (more on these sensors later, although the major acoustic sensor is affectionately called the “turtle”).
Once the kite is deployed, a pair of tom weights (each weighing 250 lbs), are attached to the bridal cables to help separate the head rope from the foot rope and ensure the mouth of the net will open. Then, after a good length of cable is let out, the crew transfers the net from the net reel to the two tuna towers and attach the doors. The doors act as hydrofoils and create drag to ensure the net mouth opens wide. Our AWT net usually has a 25 meter opening from head rope to foot rope and a 35 meter opening from side to side.
The scientists use acoustic data to determine at what depth they should fish, then the OOD (Officer on Deck) uses a scope table to determine how much cable to let out in order to reach our target depth. Adjustments to the depth of the head rope can be made by adjusting speed and/or adjusting the length of cable released.
The scientists use more acoustic data sent from the “turtle” to determine when enough fish are caught to have a scientifically viable sample size, then the entire net is hauled in. Once on board, the crew uses a crane to lift the cod end over to the lift-table. The lift-table then dumps the catch into the fish lab where the fish get sorted on a conveyor belt. More on acoustics and what happens in the fish lab in my next blog!
WOW! What an adventure!!! So I must get you caught up on some of the happenings thus far. After a mix-up where my reservation was cancelled on the Saturday afternoon flight from Anchorage to Dutch Harbor and the threat of being stranded in Anchorage for another day, I finally made it to Dutch. The weather cooperated (which is not the case more often than not), and we landed on Dutch Harbor after a quick refueling stop in King Salmon. Since we landed after 8pm, we went straight to one of the few restaurants in Dutch Harbor and had a late dinner before heading to the Oscar Dyson for the night.
Sunday morning, we went with several of the scientists out to Alaska Ship Supply to get some gear. I picked up my obligatory “Deadliest Catch” shirt and hat as all tourists do here in Dutch Harbor. We made three trips to the airport throughout the day to see if some of the science gear and luggage came, but came back disappointed. On one of our trips to the airport, we had lunch at the airport restaurant. I had Vietnamese Pho, which is a beef noodle soup, but it wasn’t nearly as good as the Pho my wife makes. 🙂 We also drove up the “Tsunami Evacuation Route” to an overlook where we could see all of Dutch Harbor and the town of Unalaska. Later, we drove around Unalaska and stopped to check out some tidal pools on our way back to the Oscar Dyson. In the afternoon, we checked out the World War II museum that was absolutely fascinating! I did not know Dutch Harbor was bombed by the Japanese and that so many American soldiers were stationed in the bunkers surrounding the harbor. For dinner, I had black cod (sablefish) at the Grand Aleutian Hotel. Yummy!
Monday we embarked on our adventure shortly after noon. We had to leave the dock because another ship was scheduled to offload there in the afternoon. The scientists’ equipment arrived on a late Monday morning cargo flight, but they didn’t make it to the ship on time!!! We couldn’t go to sea without them, so we deployed the “Peggy D” to go pick them up and bring them aboard!
Once we had our missing scientists, we left the safety of Dutch Harbor and ventured into open water. On our way, we saw dozens of humpback whales! None of the whales breached (jumped out of the water), but several of them fluked (dove and put their tail out of the water).
We started our day and a half journey to get to the starting point of our survey transects (the end point of last month’s survey). On our trip out, we experienced 6 to 10 ft seas and a 25 knot wind. It was a “gentle” welcome to the Bering Sea, but I struggled to get my sea legs underneath me. Meclizine is great motion sickness medication, but it sure knocked me out. I feel better now that I am not taking anything and am used to the rocking deck. While we made our way to our first transect, we had a couple of emergency drills. Here I am with fellow Teacher at Sea, Johanna, in our immersion suits as we completed our abandon ship drill.
On Wednesday morning, we began our first transect and did our first trawl along the transect (more on that later). I learned how to work in the fish lab collecting biological data on the catch we brought on board. I have been struggling to adjust to both my shift, which is 4am to 4pm, and the fact that the sun sets around 1am and rises at about 7am.
Thursday morning I woke on time and observed the survey scientists and crew deploying the CTD (Conductivity, Temperature, Depth) rosette from the hero deck (on the starboard side).
We also had beautiful clear skies and I was able to see Venus and Jupiter. At sunrise, I saw the GREEN FLASH!!! It was a beautiful start to the day.
We processed one mid-water AWT (Aleutian Wing Trawl) trawl that was all pollock, then switched to the 83-112 bottom trawl net (83 foot long head-rope and 112 foot long foot-rope) and pulled up a lot of jellyfish with our pollock.
Last night, I finally got a really good night sleep! This morning (Friday), I watched the CTD deployment again and learned more about the data being collected (more on this later). No spectacular sunrise this morning as it was the typical gray, foggy weather. I went up and spent some time on the bridge and Chelsea, our navigator/medic, taught me a lot about the instrumentation used for navigating the ship. There sure is a lot of technology on board!!!
From the bridge, we saw a pod of Dall’s Porpoise feeding, splashing around, and moving fast! We processed another AWT trawl of pollock that had quite a few herring mixed in. We traveled further into Russian waters than originally anticipated as we tried to identify the northern boundaries of the pollock population to get the best picture of the entire pollock range. We spotted a huge Russian trawler from the bridge!
We then headed south again towards American waters, but needed to do a quick water column profile test. Since we did not want to stop to drop the CTD again, I got to deploy a XBT (Expendable Bathythermograph)! After all the talk about safety briefings, the use of ballistics, and outfitting me with every piece of safety gear we could muster, I got ready to fire the XBT!!! Turns out, when you pull the firing pin, the XBT just slides out of the tube… no fireworks, no big bang… just a small kurplunk as the XBT enters the water. We all had a good laugh at my expense. See, scientists know how to have fun!
WOW! So I have just scratched the surface of our voyage thus far! Next time, I will give you a snapshot of what life was like aboard the ship.
NOAA Teacher at Sea
(Almost) Onboard NOAA Ship Oscar Dyson
June 29 – July 17, 2012
Mission: Pollock Survey Geographical area of cruise: eastern Bering Sea Date: June 20, 2012
My first post is supposed to be an introduction to me and what I’ll be doing for three weeks in the middle of the Bering Sea so here goes nothing! My name is Amanda Peretich, and I have been teaching biology, chemistry, and criminal science investigations (get it? CSI) at Karns High School in Knoxville, TN for the past four years. My route to teaching high school was probably not really traditional, but it’s provided me with plenty of adventures along the way, and if you know me, you know I love a good adventure!
I am so excited to arrive on the NOAA ship Oscar Dyson to participate in walleye pollock research in an acoustic trawl survey in the eastern Bering Sea (similar to this one from last summer) in a little over a week. You’ll hear plenty more about this research in the weeks to come. How am I able to do this? Well, NOAA (which is an acronym for National Oceanic and Atmospheric Administration) has a Teacher at Sea program that I had never heard of before last fall when I randomly found it in a Google search for summer teacher-y programs. Ahh, the wonders of the internet and technology! So I applied to the program (really kind of at the last-minute, which also hits on my procrastination problems), wrote some pretty good essays, had some amazing recommendations from people (shout out to Theresa Nixon and Anne Hudnall for what I can only imagine were the best letters ever!), and later found out I’d been selected as one of 25 teachers from across the U.S. for this amazing opportunity!
FUN FACT: Did you know that the Discovery show Deadliest Catch is filmed in the Bering Sea and that the operations base for the fishing fleet is in Dutch Harbor, Alaska where I will be leaving from? However, I think those rough seas on the show are due to filming during the fall and winter seasons, not summer. I’m sure I will update you in a later post about how crazy the waters are during July, but I will have to remember that it could be much more treacherous.
Not that I’ll be able to have so many photos in all of my blogs (being on a ship in the middle of the ocean = sporadic and slow internet access, thus less photos), but this little slideshow will hopefully tell you a little more about myself in picture form:
Each of my posts (which are limited to about every other day or every 3 days) aboard the ship will include a science & technology log and then a personal log, but we are also able to add additional sections as well. Help me choose which ones to add below! (sidenote: I chose the “sunset” background for the poll because of the birds in it – I hear there are plenty of birds in Alaska – now the palm trees and sun, you’ll want to replace with other trees and clouds)
Did I forget to mention that this experience is also the beginning of a new chapter in my life? My wonderful husband Michael finished his PhD in chemistry at the University of Tennessee and accepted a civilian chemist position in the fuels lab with NAVAIR in Patuxent River, Maryland. I finished out the school year and sold our house in Knoxville while he has been training and traveling to fun places like Pensacola, Florida, but I will officially move up to Maryland the day before I get on a plane for Alaska! Didn’t I say how much I love adventures and the unknown?
NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
September 4 – 16, 2011
Mission: Bering-Aleutian Salmon International Survey (BASIS) Geographical Area: Bering Sea Date: August 28, 2011
Before I begin my adventure, I should probably introduce myself. My name is Lindsay Knippenberg and I am currently an Albert Einstein Distinguished Educator Fellow at the National Oceanic and Atmospheric Administration (NOAA) in Washington, D.C. You might be asking yourself, what is an Einstein Fellow? The Einstein Fellowship is a year-long professional development opportunity for K-12 teachers who teach science, technology, engineering, or mathematics. Around 30 educators are placed within the federal government each year and our job is to inform our agency or office on matters related to education. Last year fellows were placed at the National Science Foundation (NSF), Department of Energy, Department of Education, National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), and some fellows were even placed within the offices of U.S. senators. To learn more about what I have been working on as an Einstein Fellow check out the video below, or you can go to the NOAA Education website to view some of the resource collections that my office has made for educators this year.
Before I came to Washington, D.C., I was a high school science teacher in St. Clair Shores, MI. At South Lake High School I taught Biology, Environmental Science, and Aquatic Biology. As a teacher, one of my goals was to get my students to take risks and make goals that take them beyond the city bus lines. Through my previous teacher research experience as a PolarTREC teacher in Antarctica, moving to Washington, D.C. for a year-long fellowship, and now traveling to Alaska to board a ship for the Bering Sea I hope to show my students that you can challenge yourself and step outside of your comfort zones and get big rewards. I am very excited to join the crew aboard the Oscar Dyson to learn about the science that is conducted on board a NOAA vessel and the careers that are available to my students through NOAA.
So where am I going and what will I be doing? On Friday I will be leaving hot and humid Washington, D.C. for cool and breezy Dutch Harbor, Alaska. In Dutch Harbor I will board the NOAA Ship Oscar Dyson. The Oscar Dyson is one of NOAA’s newer vessels and is one of the most technologically advanced fisheries survey vessels in the world. As a NOAA Teacher at Sea I will have the responsibility of learning about the science that is done onboard the ship, helping the variety of scientists that are onboard with their research projects, and then communicating what I learned through a blog and classroom lesson plans. The main research project that many of the scientists will be working on is called the Bering-Aleutian Salmon International Survey (BASIS).
The BASIS survey was designed to improve our understanding of salmon ecology in the Bering Sea. We will be sampling the fish and the water in the Southeastern Bering Sea to better understand the community of fish, invertebrates, and other organisms that live there and the resources available to them. The survey has been divided up into two legs. The first leg is from August 19 – September 1 and Teacher at Sea, KC Sullivan, is onboard blogging about his experience. To learn more about BASIS and what lies ahead for me check out his blog. I will be sailing on the second leg of the “cruise” from September 4 – 16 and as a Teacher at Sea I will also be blogging about my experiences. I am very excited about lies ahead for me and I hope that you will follow my adventures as a NOAA Teacher at Sea.
NOAA Teacher at Sea
Staci DeSchryver Onboard NOAA Ship Oscar Dyson July 26 – August 12, 2011
Mission: Pollock Survey Geographical Area of Cruise: Gulf of Alaska, Kalsin Bay
Heading: 213.0 (Stationary)
Date: August 6, 2011, 11:24 pm
Weather Data From the Bridge: click to view station model Dry Bulb Temp: 10.8C
Wet Bulb temp: 9.9C
Skies: Partly Cloudy, Stratocumulus
Pressure: 1013.3mb, falling then steady
Science and Technology Log
As part of our stay on shore, we took some time to travel out to a place called Fossil Beach. Fossil Beach is located on the south-eastern side of Kodiak Island, on Chiniak Bay. It is a popular attraction on Kodiak because it is near the Kodiak launch complex (a defense missile base !) and it is a popular surf beach. I, however, find it incredible for a completely separate reason: an utter abundance of fossils!
There isn’t much background information to be found on Fossil Beach. The greatest extent one might find on the internet is “Drive southeast on the only road out of Kodiak. Find fossils.” To the layperson going out fossil hunting, that should be enough information. But for me, however…I wanted to know much more about the conditions of formation, the types of fossils found there, and the age of the rocks in which I was digging. As it turns out, if I wanted to dig up information on Fossil Beach, I would have to be as clever as I was the day I discovered so many of our extinct marine critter shells. This experience turned into a bit of a scientific research project for me, as I formed hypotheses, tested my predictions, and revised my original ideas based on new findings. This, kids, is science.
Walking around the outcrop gave some insights into the environment in which this rock strata formed. The fossils were definitely nested in dark, muddy shale. I noticed lots of mollusks, particularly clamshells, at first glance. Shells were deposited in big, thick, chunks and layers. What I noticed initially is that they weren’t really fossils. A fossil, by definition, has been mineralized to a certain extent. These weren’t. However, some scientists conclude that the actual fossilization process is not necessary to call a particular dead animal a fossil – the only requirement is an extended period of time locked up in a rock.
What are the criteria for fossil formation? A dead critter needs rapid burial and possession of hard parts. An anoxic environment helps, as well. Most soft-bodied critters do not survive the fossilization process, as their flesh will decay so rapidly that there isn’t enough time to fossilize. It is not unheard of, however, to find soft parts fossilized. For example, a fly or mosquito trapped in amber is considered to be a fossil – its entire body intact in the clear, honey-colored stone.
My first question, of course, was “what was the environment of formation for this particular set of fossils?” Meaning, what type of environment did these critters live in before they croaked? We can narrow it down to two distinct, but broadly categorized areas: land? Or sea? Well, let’s think for a moment about the standard conditions for fossil formation and use that to define the environment of formation. Criteria 1: Rapid burial. Criteria 2: Possession of hard parts. Criteria 3: Anoxic environment. Consider for a moment rapid burial. In what places may we find rapid burial? Volcanic eruptions? Maybe. Land or mudslide? Also a viable solution. The next step is to rule out (or in) these two options. In a volcanic eruption, the fossils would most certainly be nested in a layer of ash. In a mudslide or a landslide, these critters would be nested in coarse-grained rock like sandstone. In our mystery case, we have fossils buried in a shale – which is a fine-grained, silty rock associated with slow-moving or stagnant water. Neither of these options work.
Let’s try criteria 2 – possession of hard parts. These shells are mainly mollusk – in particular clam shells. Where do clams live? The water. It wouldn’t make sense for a clam to be fossilized in the middle of the desert, now would it? In addition, the presence of shale does not necessarily indicate rapid burial, but it does indicate that if it were at the bottom of the ocean, it would be undisturbed for many years as it was buried.
Criteria 3 – an anoxic environment. In this case, if a clam dies at the bottom of the ocean, it may be considered an anoxic environment, but not for certain.
Hypothesis: confirmed. These critters once roamed our seas, based on Criteria 2.
The next question to ask was “how long ago did the fossilization party take place?” This one is a little more difficult to answer, but with some stealthy sleuthing and some assistance from my fellow Teacher at Sea, Cat, we came to a reasonable conclusion regarding the time frame.
At first glance on a large geologic map of Alaska, Fossil Beach is described as a Paleozoic Era beach. However, this map was so broad and basic that if we were to “zoom” in on it right down to fossil beach, our perceptions would change about the age and conditions of formation.
I thought I saw large ammonite fossils at the beach, which would have confirmed my suspicions about a Paleozoic beach. What didn’t fit, however, was that the mollusk fossils were not “fossilized” – and a Paleozoic/Mesozoic fossil like an ammonite would make the rock layers any age between 542 and 206 million years old. Now, it’s not completely unheard of to find fossil in your midst that has retained all of its qualities and still be extremely old – there are a few fossils out there that are considered fossils, but haven’t “fossilized” in the traditional sense. But 206 million years? One would suspect that is plenty of time for a fossil to fossilize. It didn’t jive. This was my first clue that maybe this beach was much younger than the broad geologic map suggested.
The broad geologic map is a bit like a mosaic. When viewed from far away, all a person may see is the color “blue”. Up close, however, the intricate pieces that make up the mosaic are individually selected for their different shades and textures. With the broad geologic map of Alaska, I discovered it wasn’t detailed enough to give me the information I needed. At a distance, there is one big picture – the colors on the map key indicate that the rock formations that make up Kodiak are predominantly Paleozoic Sedimentary rocks. This is a bit like calling a brand new pair of Louis Vuitton peep toe black patent leather heels “shoes.” It just doesn’t do it justice.
After looking further, Cat found a great article published online that discusses the nature of the formation of the beach. (I will cite it at the end of the post). Most of the information following comes from that particular document.
The paper focuses on Sitkinak Island, an island just to the south of Kodiak, but it also mentions that the formation of rocks is one and the same. The Kodiak formation is just a bit younger. As it turns out, the rocks are deposited as part of the Narrow Cape Formation, a late Oligocene/early Miocene formation. This translates into somewhere on the order of 10 million years old or so. In particular, the paper cites the Juanian stage, which is the time frame that encompasses the last portion of the Oligocene and the first portion of the Miocene.
Even more interesting is that this paper reveals the type of ocean these particular fossils came from. They originated from the outer edge of the neritic zone to the continental shelf. If you recall, the neritic zone is the point at which the lowest of the low tide is all the way out to a depth of 200 meters. Furthermore, the study reveals that the water was a cool-temperate marine climate, which means that the warmest water at the surface was about 10oC for approximately 3-4 months out of the year.
It was great to uncover the mysteries of fossil beach. The only mystery remains is, what about the Ammonite I thought I found? At this time, I absolutely cannot reconcile what happened there. There are a couple of strong leads in terms of solutions to this question: first, it may not be an ammonite at all. Second, the broad geologic map does indicate Paleozoic sedimentary rock, which would be a perfect candidate for a critter like an ammonite. Maybe the ammonites were from a completely different rock formation?
Until I get back to land and get my hands on a copy of the Roadside Geology of Alaska (I looked everywhere in Kodiak to no avail!) this will have to suffice for my level of satisfaction with respect to fossil beach. Check back to this blog often to see if my predictions were right!
Well, wouldn’t ya know it? A tsunami line is painted right on base here at the Coast Guard! There is no reason to travel or hike a ridiculous amount when you can just stay right here and visit. (However, for more information on ridiculous Alaskan hikes, please visit my other blog at www.mrsdisonaboat.blogspot.com – you’ll love it.) We did see the line on the first day, I just haven’t had time to blog about it again, plus it took a considerable amount of time for me to finally get up the nerve to ask someone to stop a car so I could snag a picture!
It didn’t look that imposing at first. At first glance, it looked like it was only about 3 or 4 feet from the ground. I thought to myself, “Gee, this doesn’t look so bad…” until I walked up to the line. It was bigger than I was! Holy cow! Even if I reached my arms all the way above my head, I couldn’t touch the lower portion of the line. The picture is extremely deceptive, that’s for sure! I thought about what it would be like to be a person who hears the siren warning of the impending emergency, and what it would be like to make for higher ground, hoping that however high you climbed would be enough to save you from the wicked influx of water.
Eesh… I am thankful that so few lost their lives, but the sight of that line is a bit imposing. Also (and not at the expense of the destruction, of course) wickedly, beastly cool.
In other news, we have successfully thrown off the bow lines and set sail! We were supposed to head out yesterday, but then something went wrong with the water system, causing a delay, and then one of the officers got sick and had to go home. Luckily, we had a replacement officer standing by to take over. We are so sorry that she came down ill, but so grateful that we had someone to take over! As we left Women’s Bay this morning, I saw many otters playing about in the bull kelp. Those little critters are too dang cute for words! They poked their heads up for a few moments before doing a graceful backflip back in to the water. But the most impressive sight of all took place about thirty minutes after we set sail. Up on the flying bridge, we saw the telltale blow of a whale. This was followed by two or three playful fluke slaps on the surface of the water.
And then, because he (or she) was as excited as we were to be sailing, the whale performed for us the most impressive breach! You, go, sister! We like the ocean, too! In my fumbling wonder, I of course, took 9 or so pictures of the breaching whale using stop-motion photography for you to see below. Too bad Marshmallow is in the way.
I am so happy and thankful to be out on the sea. Now I see why people love it so much. It has an interesting dichotomy. On one hand, I feel so small – a large, blue, fog-covered expanse stretches out before me, nothing in sight for miles and miles. On the other hand, I feel enormous. As we left the bay, we traveled past the peninsula we had walked on so many times before. Along the shoreline was an oil spill containment kit stored in a freight-train style container. It looked so tiny from where we stood on the flying bridge. It was as if we swapped positions – now we were the behemoths, and the spill kit was nothing more than a busted up shoreside lego.
I’m fascinated by the scales of this magnificent place – more so about how I fit in to them. Everywhere I turn, the sizes of things – animals, projects, decks, horizons, anti-seasick meds, stories, waves, meals, ocean expanses, rock outcrops – everything, everything is large, even that which is the tiniest and seemingly insignificant. Here is the place where small things commit powerful acts – a tiny three-foot swell makes its presence known in more ways than one, and a small anti-seasick pill can keep me from worshipping at the feet of its effects. A big ocean can throw around an enormous ship, and a humpback whale can effortlessly cut through it with its imposing fins. A project seemingly small (at least in this context of one ship, one crew, one survey leg, and one set of scientists) can spread awareness about the health of our fisheries to a something the size of a nation. To top it off, we are completing it along the coast of our largest state – one that blends quietly in with our neighbors to the north, but not forgotten as a beautiful and expansive supplier of natural resources. Everything small is large out here, and everything large is large. For those who have spent too long at the dock, today they are home. For those who have never left a dock before, today we feel your freedom. And we love it, too.
*Information on Sitinak Island/Fossil Beach was summarized from the following:
Allison, Richard C. A late Oligocene or Earliest Miocene molluscan fauna from Sitinak Island, Alaska. United States Department of the Interior, Washington; 1981.
NOAA Teacher at Sea
Staci DeSchryver Onboard NOAA Ship Oscar Dyson July 26 – August 12, 2011
Mission: Pollock Survey Geographical Area of Cruise: Gulf of Alaska
Location: 57.43287 N, 152.28867 W
Heading: 241.2 (Stationary)
Date: August 3, 2011
Weather Data From the Bridge Overall Weather: Clouds and fog
Science and Technology Log
One of the most serious emergencies that can take place onboard a ship is a fire. The NOAA Ship Oscar Dyson has many security measures in place in the event of a fire while underway. During our time in port, the crew of the Dyson planned a ‘’Safety Stand Down” Day to review safety protocol for all types of emergencies, particularly what the crew should do in the event of such a serious issue.
Before we began discussing some of the features of fire-fighting and emergency equipment, we participated in a survival activity that will certainly be used for the first days of school in my AVID class. The activity consisted of a list of 15 items that we had in a mock abandon-ship emergency situation. We were supposed to rank order the items of greatest to least importance for survival. Some items were quite obviously important (water, food, and shelter, for example) and some were quite important but at first glance appeared to be about as useful as chewing gum. There was a third group of items that appeared to be important, but in reality, ended up being about as valuable as a lawn ornament. We rank ordered the items first on our own, and then formed groups of four or five to discuss our lists and come up with a group consensus of what is valuable. As I predicted, repurposing items was the name of the game and those seemingly useless chewing gum items realized their full potential for being used for some other function. Overall, I won! I will be accepting applications for spaces in my life raft in the event of an emergency. Preference will be given to those who can demonstrate strong paddling capabilities and have a deep aptitude for celebrity impersonations for entertainment purposes while on the raft. Although all candidates will be judged carefully, those who write detailed, yet succinct and poignant essays will be given highest consideration due to limited on-raft seating.
After we finished the safety exercise, we were given the opportunity to take a look at the fire-fighting gear. Think about this: what happens when there is a fire at home? It is usually detected by a smoke alarm, then, if there is time, the type of fire is determined. Did it start with grease in the kitchen? Or is it coming from an unknown source, maybe like an electrical fire? The type of fire will determine what can and cannot be used to put it out. If the fire can’t be put out quickly, the next step is to…call…the…fire…department. Now, think about this: What would happen on a ship in the event of a fire? Well, many people are typically on watch to ensure that fires don’t start to begin with. But fires can start on board in all of the same ways they can start at home. So, in preparation for this, the ship must be equipped not just for fire, but for all kinds of fire. If the fire can’t be put out quickly, the next step is to…call…the…fire…department…but wait! That really can’t be done. Who, then, do we call? (Not the Ghostbusters, but good try.) The crew doubles as the fire department. In fact, any person who is on the ship is a member of the fire-fighting team to a certain extent. My job is to be accounted for and stay the heck out of the way so the pros can do their job.
All of the crewmen are trained in firefighting procedures. There are two fire lockers, one fore and one aft of the ship. Inside the fire locker is a treasure trove of nozzles, hoses, and fire axes. They are ready for anything on the ship because they have equipped themselves with a variety of means with which to fight different kinds of fires.
What I found both interesting and important is that all of the hose lengths must be able to reach any connection on the ship so that all parts of the ship are covered in the event of a fire. This can easily be explained if you think about a poorly designed sprinkler system. If your sprinklers don’t cover all areas of the yard, you end up with conspicuous brown patches in the grass where the water doesn’t reach. However, if the sprinkler system is set up correctly, no brown patches exist. The Oscar Dyson requires that all of the hoses are long enough so that there are no “brown areas” on the ship. If appropriate and necessary, the hoses will pull seawater out directly from the ocean to fight a fire in favor of the purified water onboard. Usually, they prefer to use carbon dioxide to fight the fire. It’s relatively benign in terms of dangerous reactions that could potentially take place. For example, if there was a grease fire onboard, it wouldn’t make much sense to put water on it, but Carbon Dioxide would be a great option.
Next, we were given a demonstration of all of the nifty features of the firefighting gear. Ensign David Rodziewicz, the head safety officer, gave pointers on how to effectively put fire-fighting gear on. The goal is to be able to get in and out of fire gear in less than two minutes, with the ideal time being less than a minute. ENS Rodziewicz indicated that the most important way to be successful with suiting up is to have the gear properly set up – if boots are tipped over and gloves are strewn all over the place, not much will be accomplished in the time frame allotted – and being able to fight a fire quickly, while critical in all areas, is imperative on a boat. Where land-based fires are a tragic and sobering experience, there is often an escape. One can leave and go to a wide parking lot or out to the street away from the flames. On the ship, the only place to go if things really take a turn for the worse is the ocean. This is why timing is so important.There are some neat features on the fire-fighting equipment. The air supply tanks are equipped with a 45-minute supply of air. Most fire fighters are not expected to stay in an active fire area for that long, but the supply is large enough just in case there is a problem. There is no need to keep time while fighting fires. A “heads-up” display is clearly visible in the fire mask, with green, yellow, and red indicator lights representing the percentage of air left in the tanks. The batteries for the light displays are changed quarterly – an important thing to check off on a to-do list! Of all of the things to remember to do on a ship, it seems to me like that would be an easy task to forget. But, they never do. Another interesting feature is the communications system. Each fire-fighting mask has a built-in communications system, so there is no need to take a radio in to an area with flames. It’s almost like having a fire-fighting Bluetooth. Each coat is also equipped with a flashlight and an emergency nylon strap in case of an emergency. The neatest feature to me was the emergency bypass for the oxygen tanks. If a crew member runs out of air, he or she can “latch” on to another person’s tank by ENS Rodziewicz utilizing a connector hose from the back of the rescuing party’s tank. This will give approximately a ten minute air supply, although points out that if one finds himself or herself in that kind of a situation, he or she should not be in a fire zone for an additional ten minutes. The emergency air supply is to safely remove a crew member only – not for fighting fires.One of the most useful ways to fight fire on a ship is to simply cordon off the area and then let the fire run its course in the offending room. On the ship, there are many fire-retardant walls built into the bulkhead. At that point, the fire fighters will utilize a tactic known as “boundary cooling.” When you shut off a single room in the ship, the above and below decks can still conduct heat. Therefore, the crew will spray a layer of ocean water in the rooms directly above and below the target area to ensure that the fire does not spread above or below floors. Water has a high specific heat, so it acts as an excellent energy absorber. This tactic is called boundary cooling, and is used often used in fire-fighting on a ship.Afterward, we watched the crew practice putting on, activating, and utilizing their fire-fighting equipment. Each person who is responsible for fire-fighting has a partner who assists him or her in getting suited up, changing out air supply tanks, and assisting in other duties as necessary.Here, Cat and I are pret-a-porte in our stylish life-saving devices. Will we go into the water? Check out my other blog to find out…
From there, the day got really exciting, but if you want to read about it, you’ll have to visit my other blog at www.mrsdisonaboat.blogspot.com– a quick hint: it involves a gumby suit and a big splash! It’s not for the faint of heart. Here’s a preview in the picture to the left. Also, be sure to check out Cat’s blog: www.blueworldadventures.blogspot.com to see what she’s been up to! Cat does some incredible cartoons that are really funny and informative, so she is capturing this adventure in a completely different light. We make a great team!
Yesterday, Cat and I went out to Fort Abercrombie. Fort Abercrombie was an established World War II outpost that was designed to defend American soil in the event of an attack from the Axis Powers. We found this really interesting interpretive trail called the Wildflower Trail. Along the trail, there were informative signs about various wild flowers, their scientific name, their Inuit name, and uses for the roots, blossoms, stems, and leaves. After encountering a sign, it was a sure bet that we would see the celebrity flower just a few clicks up the trail. The trail carried us to a decrepit lookout post over the inlet that we could enter into and see what the defenders of our nation saw when they looked out on the glass blue waters of the bay.
Old buildings stood steadfast, fighting reclamation by the forest while many had a legacy left only by a sign pounded in to a rotting foundation. Again, I found myself trying to tell the story of those who used to call this enchanted forest home.
We also (sound trumpets!) saw a Kodiak Brown Bear! There is a difference between a Brown Bear, a Kodiak Bear, and Grizzly Bear – mainly demographic. A Brown Bear (Ursus arctos) is called a brown bear because it is found in coastal areas. Kodiak Bears are the largest of the Brown bears and are found only on Kodiak Island. Inland bears (like the ones you find in Yellowstone) are called Grizzlies (Ursus arctos horriblis). Bears on boats are called Marshmallows. All bears (excepting Marshmallow himself) are in the genus Ursus. Brown bears, Grizzly Bears, and Kodiak Bears are Ursus arctos, while Marshmallow’s distant cousins to the north are Ursus maritimus. After discovering this as his namesake, Marshmallow was quite revolted. He has decided to write a strongly worded letter to the Linnaeus Society as the term maritimus paints a less menacing and voracious picture of polar bears than does the Grizzly’s namesake.
He has suggested instead to be called Ursus kickyerbuttus. I maintain that Marshmallow should be renamed Ursus domesticus stuffedus wimpus, because the closest he has ever been to a salmon run is from the comfort of his 60 inch HDTV. He has a stateroom for crying out loud.
As we drive along the road, we slow down to a crawl at all of the river crossings hoping to see Kodiak Bears. Our luck was good that day, because we saw three in a matter of about 4 hours. Here he is now.
A fisherman nearby hypothesized he was a juvenile male, about 2 or 3 seasons away from his mamma and on his own as a hunter. He was pretty indifferent to the existence of people, but not menacing in any way. He ambled along, chasing after magpies and hopping in and out of the water. It was neat to see him up so close, but still have the safety of the bridge to keep us at a safe distance. This was of course, until he decided to climb up onto the road. He was quicker than I would have liked him to be!
After dinner, we were driving back to the ship along Women’s Bay and one ran out in front of the car! His shoulder blade was at the same level as the roof of the Impreza we were driving – no fish tale. He glanced casually at us and loped off into the trees toward the salt marsh. The next creek up the bay hosted a third bear, but we only got a glimpse of him as he was gone by the time we turned the car around. It was really a blessing to get to see (more than once!) such neat little critters. And by little critters I mean large toothed, long clawed beasts that have the capability to chew your head off in one fell swoop. Thankfully, they are more interested in salmon at this time of year, and really don’t have much of a taste for people. (In defense of Mr. Kodiak, there are more casualties from dogs in a given year than there are fatal maulings in ten years from Kodiak Browns. We would have much more to worry about if we tasted like Salmon or Salmonberries, as this is what comprises the majority of their diet. However, they should be treated with a healthy respect – especially a momma bear with her cubs.)
It has been an action packed week so far. We are hoping to learn as much as we can about the island while we are here, and we are making the best of being in port while we wait to set sail. It’s been wonderful to walk out on the peninsula every morning and have some time to myself to show gratitude for all that has been done for me to get me out here and experience this first hand. The standing joke when we witness something truly spectacular is to say “I think in my evaluation of the Teacher At Sea program I am going to suggest that they actually find places for us to go that aren’t so ugly. This place is such an eyesore…” I hope you sense the sarcasm dripping in my voice.
True or False? Sea Stars are Echinoderms that can regenerate lost body parts.
Answer: True. “Sea stars are remarkable, as they are able to regenerate lost or damaged parts of their bodies. An arm that is broken off can be regrown. Some species can actually regrow a complete new body from a single severed arm, if it is attached to part of the central disc.”
NOAA Teacher at Sea
(Almost) Onboard NOAA Ship Oscar Dyson July 26 – August 12, 2011
Mission: Pollock Survey Geographical area of cruise: Gulf of Alaska Date: July 23, 2011
Hello, from Denver, Colorado! My name is Staci DeSchryver, and I am an Honor’s Earth and Physical Science teacher at Cherokee Trail High School in Aurora, CO. Our school is the newest addition to the Cherry Creek School District family, but starting our ninth year is hardly enough to make us the babies any longer. We are an outstanding school with absolutely outstanding students, and I can’t wait to share this experience with them! I will be starting my eighth year teaching this fall, and my seventh year at CTHS. I’ve been around for a while, and Trail is definitely my teaching home.
I applied tor the NOAA Teacher At Sea program because our oceans are vast, largely unexplored, and a critical planetary resource. I love their mystery. More importantly, I love that we have the technology to uncover what hides beneath the surface. In addition, I am a firm and vocal believer that our ocean fish supplies are a lynchpin in our food supply. How so, you ask? I’ve broken it down into a simple and digestible equation:
Overfishing = fish can’t reproduce to keep up with the demand = fish become scarce = people starve = sad, hungry people.
Therefore, because few people on this planet enjoy being sad or hungry, NOAA (The National Oceanic and Atmospheric Administration) works tirelessly to ensure that we have sustainable fish populations now and in our future.
As part of this tireless work, I have the chance of a lifetime — to sail on the NOAA Ship Oscar Dyson! The Oscar Dyson will be completing a stock assessment survey (data collection) on Walleye Pollock, a smart-looking fish that is a staple of the American (and world) diet. I am excited and nervous! I have never been on a ship before — not even a cruise ship! Come to think of it, I have never entered the ocean past knee-depth. (Thanks, Mom.) While the training has prepared me well, I know nothing can prepare me for the size, depth, and wealth of knowledge and surprises that are surely in store for me.
Please be sure to check the links to the Ship and the Mission! The sites there explain what we will be doing in clear detail.
As far as a little more information about myself, I am currently packing up, tying up loose ends at home, and making sure all of my electronic equipment is in working order before I leave. I have also just learned from a fellow TASer that using the word “boat” for a “ship” is quite improper etiquette and akin to swearing. How did I miss that? Therefore, I am currently seeking out synonyms for “ship” and “vessel” to keep my writing nice and spicy without angering anyone who holds my life in their hands.
The next time you hear from me, it will be from the Gulf of Alaska on my mission to help protect our fish populations, spread the word about scientific careers, and develop killer lesson plans that teach our students the science of Oceanography! Cheers!
NOAA TEACHER AT SEA CATHRINE PRENOT FOX ONBOARD NOAA SHIP OSCAR DYSON JULY 24 – AUGUST 14, 2011
Mission: Walleye Pollock Survey
Location: Kodiak, Alaska
Date: July 27, 2011
Weather Data from the Bridge
True Wind Speed: na
Air Temperature: 14° C dry/12° C wet
Air Pressure: na
Latitude: 57.44° N, Longitude: 152.31° W
Ship heading: n/a
(Limited data, as ship is in port)
I’ve received an in-depth tour of the ship and labs, and I am starting to piece together how the “Acoustic Trawl Survey” works. Basically, NOAA is responsible for monitoring the populations of walleye pollock and accomplishes this task in several ways. The acoustic trawl survey is one part of how this is done.
The science team identifies particular transect areas in the Gulf of Alaska. The ship travels to that area, then transmits acoustic signals about once per second as it travels along each transect. The returning echo gives scientists an initial measurement of the abundance of organisms in the water below the ship. Just “listening,” however, is not enough. We also have to sample populations physically to determine the ages, sizes, and species of the organisms. The ship trawls for these additional data.
A trawl is a large net towed behind the ship to catch fish and other organisms. The individuals (of all species) in the catch are identified and counted. Cameras (three) are mounted inside the back of the trawl (codend) to collect images as they pass through the trawl. From this larger catch, a sample of the walleye pollock (about 300 individuals) are dissected to determine sex, diet, measured (length and weight) for size and aged by looking at (yes) their ear bones or otoliths. I’ll cover all of this in depth once I have been able to do it and see it in action, but that is the gist.
I think first impressions are important. Alaska? Alaska is impossibly big and impossibly green. Too big, perhaps to describe with common adjectives. It took me about two days of travel from the 4-Corners to make my way up here: a Beechcraft 1900 from Cortez to Denver, then flights from Denver to Seattle and Seattle to Anchorage. I spent the night in Anchorage and wandered the city at midnight… …not that you can tell that it was so late from the pictures.
The next morning I took off from Anchorage and met up with the crew and scientific party onboard the Oscar Dyson in Kodiak, an island the size of Connecticut in the Gulf of Alaska
As for how ‘impossibly green’ Alaska is, I was thinking about the reasons Georgia O’Keeffe gave for moving from New York City to New Mexico in 1949. She said (and I paraphrase) that she wanted to use more vibrant colors in her palette of paints than just green. Ms. O’Keeffe would have it rough here in Alaska: greens, greys and blues abound. Adventures in a Blue World Issue 6 may not convince you of the colors of Alaska, but I hope it gives you a grasp of its size.
I’ve already settled in to the ship and my stateroom. My stateroom is small but comfortable, and I share it with a woman who is part of the scientific NOAA team. Interestingly, she worked for the same professor at the Rocky Mountain Biological Laboratory in Gothic, Colorado as an undergraduate that I did. Very Small World.
We are docked in Kodiak for a few more days than anticipated: we are awaiting the arrival of another deck-hand, and there are a few repairs that need to be made to the ship. Once we get started, I will be working the 4am-4pm shift, and taking part in whatever science is taking place. In the meantime, I get to ‘nose around’ Kodiak, go for hikes and runs, check out museums (see below), and eat as many salmonberries as I can stuff into my mouth.
NOAA Teacher at Sea Anne Mortimer Onboard NOAA Ship Oscar Dyson July 4 — 22, 2011
Mission: Pollock Survey Geographical area of cruise: Gulf of Alaska Date: July 14, 2011
Weather Data from the Bridge Conditions: sunny and windy
Air Temperature: 10.1 ⁰C
Sea Temperature: 7.6 ⁰C
Wind direction: 237 ⁰C
Wind speed: 20 knots
Wave height: 2-3 ft.
Swell height: 5-6 ft.
Science and Technology Log
My last blog I said that I would talk more about the cam-trawl. This technology was created by scientists working on the pollock survey. The purpose behind the cam-trawl is to be able to put a net in the water with an open cod-end (basically a net with an opening at the end), and have images of the number, species, and size of fish that went through the net. Of course, sometimes some fish would have to be brought on deck so the otoliths and stomachs could be taken back to the lab in Seattle. Overall, this could eliminate taking so many research-based fish and/or invertebrate samples. When cam-trawl is used on acoustic-trawl surveys, the echograms can be matched up with the stereo-camera images which can provide more data about the distribution of fish or other marine organisms in the water.
How the cam-trawl works: it is a stereo-camera system that takes snapshots of whatever comes through the net. These images allow the research team (including me on this leg) to determine the approximate number, species (some, not all), and size of fish that go through the net.
The pictures are taken at the same time, but because of the slight difference in camera position, they look similar but not identical. You can mimic this with your eyes by looking at an object with only your right eye, then switching to looking with only your left eye. Did