Geographical area of cruise: Channel Islands, California
Date: May 4, 2016
Weather Data form the Bridge: 0-2ft swells, partly cloudy, slightly hazy
Science and Technology Log:
We’ve been waiting for you, rockfish. We meet again, at last. You might wonder why scientists need to know the location and population densities of rockfish in the Channel Islands National Marine Sanctuary. Well, rockfish are tasty and commercially important, plus they are an important component of healthy marine ecosystems. To estimate how many there are and where they’re at, you’ll need lots of equipment and fisheries biologist, Fabio Campanella.
Fabio Campanella and Julia Gorton getting some fresh air. Breaks are important to help them stay on target.
Monitor showing the EK60 in action. Your eyes can deceive you…watch out for the acoustic dead zone!First, let’s start with the equipment. Shimada has an EK60, which is essentially a fish finder: the computer’s transducer sends out sonic “pings” that become a single acoustic “beam” in the water. It covers about 7° at one time, so think of it as taking a cross section of the water column. The beam bounces off any solid object in the water and returns to the transducer. The size and composition of the object it hits will affect the quality of the returning pings, which allows Fabio to discern between seafloor, small plankton, and larger fish, as well as their location in the water column. One drawback of this system is the existence of an acoustic dead zone, which is an area extending above the seafloor where fish cannot be detected (think of them as sonar blind spots).
Do. Or do not. There is no try. Fabio Campanella hard at work in Shimada‘s Acoustic Lab.
It’s a trap! Nope, it’s a starry rockfish (Sebastes constellatus) found in the CINMS.
Ideally, acoustic data collection is done simultaneously with ground truthing data. Ground truthing is a way to verify what you’re seeing. If you think the EK60 is showing you a school of herring, you can run nets or trawls to verify. If it’s in an area that is untrawlable, you can use ROVs or stationary cameras to identify fish species and habitat type. Species distribution maps are also useful to have when determining possible fish species.
EK60 data shown on the bottom; ME70 data on top right; 3-D visualization of the school on the top left. Witness the power of this fully operational Echoview software.
If Fabio finds something especially interesting on the EK60, such as a large school of fish, he can refer to the data simultaneously collected by the ME70 multibeam sonar to get a more detailed 3-D image. Since the ME70 uses multiple beams and collects 60 degrees of data, he can use it to (usually) get a clear picture of the size and shape of the school, helping him identify fish species and density. So why does he use the EK60 first if there is so much more data provided by the multibeam? Well, the amount of data provided by the ME70 is incredibly overwhelming; it would take weeks of data analysis to cover just a tiny section of the marine sanctuary. By using the EK60 to cover large areas and the ME70 to review small areas of specific interest, he is able to create fish distribution and density maps for the largest areas possible.
After collecting data from the two sonars, it needs to be processed. The method you use to process the data depends on your goal: biomass, population densities, and fish locations are all processed differently. Since rockfish are found close to hard, rocky seafloor, data analysis becomes quite complicated, as it becomes difficult to discriminate the fish from the seafloor. Hard bottoms also introduce a lot of bias to the data; for these, and other, reasons there are very few hard bottom studies for Fabio to refer to.
Cleaned data. I’ve got a good feeling about this.But back to the data analysis. Once data is collected, it is loaded into Echoview software. Fabio then removes the background noise coming from other equipment, averages the data to reduce variability, and manually modifies the seafloor line (rocky bottoms with lots of pinnacles give incorrect bottom data). This last step is crucial in this mission because the focus is on rockfish who live close to the bottom.
School of fish shown on the right of the screen and the frequency response shown on the left. Fish are not lost today. They are found.The clean echogram is then filtered for frequencies falling in the suitable range for fish with swimbladders (a gas-filled organ used to control their buoyancy). Object with a flat response at all frequencies (or slightly higher at low frequencies) will most likely be fish with swimbladders, whereas a high response to high frequencies will most likely not be fish (but it could be krill, for example). Once Fabio has made the final fish-only echogram, he exports the backscatter and uses it to create biomass or density estimates. All of these steps are necessary to complete the final product: a map showing where rockfish fish are in relation to the habitat.
Krill shown on the right and frequency response shown on the left. Judge them by their size, we do.
The final product. When making accurate maps of rockfish, there is no such thing as luck.Personal Log:
It seems I overpacked sunscreen…12 hours of my day are spent in the acoustics lab staring at monitors, with brief breaks every so often to look for whales and other wildlife. This mission is so technical. I am grateful for the hours spent asking the scientists questions and having them explain the details of their work. Lately, the big screen TV in the lab has been turned on with some great movies playing. So far we’ve watched, Zootopia, Deadpool, LoTR, and, of course, The Force Awakens. May the 4th be with you…always.
Word of the Day: Holiday.
A holiday is an area in your bathymetry map that does not include any data (think of it as “holes in your data”). It’s like you’ve painted a picture, but left a blank splotch on your canvas.
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
Visibility: 10nm
Air Temperature: 11.4 C
Barometric Pressure: 1002.4 mbar
Sky:Overcast
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 echogram that shows data from the transducers.
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.
This is a picture of pollock entering the net taken from the CamTrawl.
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.
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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.
Here the scientists, LT Rhodes, and ENS Kaiser assess the catch.
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!
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Personal Log
Here is one of many jellies that we caught. .
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.
Up on the bridge making the turn for our next transect.
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?
Location Data
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.
Screenshot showing our transects on leg 3 of the pollock midwater acoustic survey. Fish icons indicate where we validated acoustic data with biological sampling. Hydroacoustic data were collected continuously along north/south transects.
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).
An animation of dolphin echo-location (courtesy of Discovery of Sound in the Sea).
On a typical recreational watercraft, this technology can be found in the form of a “fish-finder.”
Recreational “fish-finders” can be found on many personal watercraft (courtesy of Discovery of Sound in the Sea).
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.
Commercial fishing boat using hydroacoustics to locate fish. This animation illustrates how a fish shows up as an arch on the onboard display (courtesy of Discovery of Sound in the Sea).
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).
Illustration of the Oscar Dyson showing the hydroacoustic transducers located on the centerboard and the hull of the ship.
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).
An echogram taken from the Oscar Dyson. Shades of yellow and red show extremely large, dense schools of fish. The solid red at the bottom of the picture is the bottom of the sea which is at 94.12 meters at this location.
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.
X-ray of fish showing the presence of a swim bladder (courtesy of DeAnza College).
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.
A close look at part of Transect 27. In this echogram, the area backscatter numerical values are included. At the top of the water column, you can see what are probably jellyfish which have little backscatter since they have no swim bladders. Along the bottom are groundfish. In the center of the water column are several large schools of Walleye pollock with strong backscatter. The square that has a value of 2403.54 shows several large schools!
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.
The BIG picture. This is the combination of hydroacoustic data and biological trawl data analyzed to show what the entire walleye pollock population looked like for 2009 (courtesy of the Alaska Fisheries Science Center www.afsc.noaa.gov/Publications/ProcRpt/PR2010-03.pdf). Analysis is still being done on the current survey. This year’s results will be out in a report this fall. Expect some changes!
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!
How might climate change affect fish sticks? Click on the picture to read more!
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.
Personal Log
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!
Map of the Bering Sea showing both the International Date Line and the 180th longitude. Our closest point to Russia was 12 nautical miles from Cape Navarin which is very close to 180 longitude.
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.
The Order of the Golden Dragon!
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.
NOAA Teacher at Sea Kathleen Harrison Aboard NOAA Ship Oscar Dyson July 4 — 22, 2011
Location: Gulf of Alaska Mission: Walleye Pollock Survey Date: July 12, 2011
Weather Data from the Bridge Air Temperature: 10.15° C, Sea Water Temperature: 7.6° C
True Wind Speed: 12.26 knots, True Wind Direction: 191.38°
Very foggy, visibility < 1/4 mile
Door open on bridge to hear other fog horns
Latitude: 56.07° N, Longitude: 158.08° W
Ship Heading: 24°, Ship Speed: 11.7 knots
Science and Technology Log: Finding Fish
In a previous log, I talked about using nautical charts and trawling as 2 methods used in calculating the biomass of Walleye Pollock in the Gulf of Alaska. Finding the fish to catch is tricky business in the ocean, they don’t usually come up to the surface and say hi. The NOAA scientists working on the Walleye Pollock Survey spend a lot of time looking for fish, so that their trawling efforts won’t be wasted (that is the general idea, anyway). How do you look for fish in the ocean? With acoustics, of course, another method used in calculating biomass.
Acoustics is the use of sound, which will travel through the water, and bounce off of objects that it hits. There is Simrad ER60 echosounder that operates 5 transducers mounted on the center board under the ship, and it continuously sends out sound waves.
The Simrad ER60 echosounder sends sound directly under the ship, finding fish anywhere in the water column.
In the Acoustics Lab of the Oscar Dyson, the data from the multi-beam echosounder is being studied all of the time. The sound waves leave the device, travel down, hit the swim bladder in a fish (the fish doesn’t even know), and reflect back to the ship. The time it takes for the sound to return is used to calculate the distance down, and a computer generated picture called an echogram is produced.
The echogram shows plankton at the surface in blue/green, fish near the bottom as red/brown spots, and the ocean floor as a red/brown line.
The echogram tells the scientists several things. The surface of the water is shown, with surface dwelling organisms such as krill, phytoplankton, zooplankton, and juvenile fish. The fish that are mid-water are shown as well, showing up as red or blue dashes or blobs. This is where the Pollock usually are. Some fish are bottom feeders, and the red and blue dashes on the bottom represent those. The ocean floor is also shown, which is very important when choosing which type of trawl to use. If the bottom is flat, the Poly Nor’Easter could be used to capture to fish on the bottom. The Aleutian Wing Trawl might be used in mid water if the bottom is rocky and irregular.
Now, looking at the fish from the surface is nice, but wouldn’t it be better to see them close up? Of course! The scientists have another tool at their disposal, and no, it isn’t me diving down to the fish (brrr). This tool is called a Drop Target Strength, or DTS.
The Drop Target Strength (DTS) can be lowered into the water, and get closer to the fish. The information is fed into the computer by a water proof cable.
About once a day, or every other day, the DTS is lowered over the side, and it starts sending out sound waves (3 pings/second), just like the echosounder mounted on the ship. The advantage with the DTS, though, is that it is closer to the fish, giving a more detailed and accurate picture. Individual fish can be sighted. Taking a picture of a fish is kind of like taking a picture of a toddler, they don’t hold still very well. So, a count of the fish on the echogram might not be exact. Also, they might change the angle of their body, making the sound wave reflect off their swim bladder at a different angle. The colors on the echogram are significant: brown and red mean a strong signal, yellow is medium, and green and blue indicate a weak signal.
Studying the echogram from the DTS gives scientists a better picture of where the fish are. Each individual wavy line is probably a separate fish.
The scientists will study the echograms to determine where the fish are, and make a decision to fish or not. Once fishing begins, they will move from the acoustics lab to the bridge, and study the echograms there. An estimate of how many fish are in the net is made, and then the scientists will ask the crew to “haul back” the net. (I am learning a whole new language!) Then, things get very busy as we head to the fish lab to process the fish.
Here are the NOAA scientists that I am privileged to work with on the Oscar Dyson: (left to right) Darin Jones, Fish Biologist, Denise McKelvey, Fish Biologist, Neal Williamson, Chief Scientist.
New species seen:
Giant Pacific Octopus (juvenile, 1 cm)
Opalescent Squid
Chinook (King) Salmon
Egg yolk jelly fish
Sculpin (juvenile)
North Pacific sea nettle
Spud sponge
These are juvenile squid, about 2 cm long. They are nearly transparent.This is a juvenile Giant Pacific Octopus, only 1 cm wide, complete with 2 huge eyes, and 8 perfect legs.
Personal Log
My days have developed a routine now: wake at 3:30 am (ugh), start my shift in the acoustics lab about 4:00, breakfast at 7:30, lunch at 11:30, end my shift at 4:00 pm, dinner at 5:30, shower, in bed by 8:00.
See the orange life saving ring? My window is just to the right of the ring. The 3 white canisters on the back wall hold life rafts that inflate upon release of the canister.
In between these times, I work on my Teacher at Sea log, post pictures on Facebook, read and answer e-mail, visit the bridge and ask lots of questions, and of course, process fish whenever there is a trawl (very fun). Today marks the halfway point of our cruise! The ship is quieter than I thought, even though there are 35 people on board, the most that I ever see might be 10 during mealtimes. There is constant background noise of the ship’s engines, waves hitting the bow of the ship, creaks and groans of the furniture as the ship rolls, but I am used to it now, and hardly notice it. I am thankful for the calm weather that we have had so far.
NOAA Teacher at Sea: Sue Zupko NOAA Ship: Pisces Mission: Extreme Corals 2011; explore the ocean bottom to map and study health of corals and their habitat Geographical Area of Cruise: SE United States deep water from off Mayport, FL to St. Lucie, FL Date: June 4, 2011
Weather Data from the Bridge Position: 29.1° N 80.1°W Time: 11:00 EDT Wind Speed: calm Visibility: 10 n.m. Surface Water Temperature: 27.6°C Air Temperature:27.6°C Relative Humidity: 72% Barometric Pressure:1018.4 mb Water Depth: 85.81 m Salinity: 36.55 PSU
When the strong current from the Gulf Stream stretched the tether of the ROV and broke one of the three fiber optic cables inside, it was time to come up with a new plan. What do you do in the middle of the ocean if the main gear is not functioning? Plan B. Well, Plan B was using the spare fiber optic in the tether. The spare one then broke as a result of being rubbed, most likely, by the sharp end of the original broken fiber during the next dive. Now we had to go to Plan C . Fortunately the ROV crew is experienced, and, like Boy Scouts, were prepared. They brought a spare ROV and tethers from their lab in La Jolla (pronounced La Hoya), CA just in case. The ship is running the sonar gear back and forth over the area we plan to dive tomorrow, mapping out the bottom, looking for coral mounds. This process is called “mowing the lawn” since you run the beams back and forth to get complete coverage of the bottom, and it looks like the lines on the lawn left by the mower. Think of the beam as having the shape of a flashlight’s beam shining on the floor. Another interesting feature is that the acoustic beam can also read what fish are present. It needs to have a swim bladder for the signal to bounce back. When it does, based on the sound, an experienced acoustician can read what fish the signal represents. Sharks don’t have a swim bladder like most fish do so their signals are a bit more difficult to read.
I was just up on the bridge and it seems we hit “pay dirt” (like gold miners). The captain had been explaining to me a symbol shown on the Electronic Chart Display System (ECS). It looks like a graphic math problem showing the intersection of lines, in this case one line running on a 110° angle with three lines parallel to each other intersecting it. The line in the middle is a bit longer than the other two. I asked how he knew what that symbol meant. Apparently, there is a book for everything on the bridge. He whipped out his handy-dandy book entitled, Chart No. 1. It is a key to reading nautical charts (maps). He searched for the correct page with bottom obstructions of all types and showed me that symbol and what it means. Whenever I have a question, the bridge crew whips out a book of some type to let me see the answer. It’s really interesting. The Pisces is a really modern ship with the latest electronic navigation and scientific features. The other day I asked about navigating without power. There is a book for that. Bowditch American Practical Navigator has everything you need to know about crossing the ocean without electronics. As it says on my classroom door, “Reading makes life a lot easier.” Turns out that symbol is a shipwreck.
Laura Kracker looks at maps
But I digress. Back to the pay dirt (we struck gold). Laura Kracker, our geographer started getting excited. “Look at this! Look at this! Write down these coordinates.”
She went running back to the acoustics lab (where they use sound echos to map the ocean floor and the presence of fish) to mark the location along the transect (lines we’re running) because we apparently were over coral mounds. Using information gathered by others in years past as a guide, they were mowing the lawn with the sonar to find interesting habitat to study with the ROV. As the ship went back and forth along the planned transect to develop a much better map than existed, Laura would radio the bridge about any changes to the courseto pinpoint the best areas for us to study over the next couple of days.
ROV crew swtiches gear from one ROV to the other
Everyone was very excited. So, although the ROV had to be switched out, which took a lot of work, we made good use of the time on the ship. After a whole day of mapping, it’s now late at night and the map looks gorgeous. This is important work and many cruises are devoted entirely to mapping. Andy David, our lead scientist, says this acoustic mapping is useful to many people and will allow more precise coral surveys for years to come.
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