NOAA Teacher at Sea
Lindsay Knippenberg
Aboard NOAA Ship Oscar Dyson
September 4 – 16, 2011
Mission: Bering-Aleutian Salmon International Survey (BASIS) Geographical Area: Bering Sea Date: September 11, 2011
Weather Data from the Bridge Latitude: 58.00 N
Longitude: -166.91 W
Wind Speed: 23.91 kts with gusts over 30 kts
Wave Height: 10 – 13ft with some bigger swells rolling through
Surface Water Temperature: 6.3 C
Air Temperature: 8.0 C
Science and Technology Log
On a calm day letting out the CTD is easy.
Today Jeanette and Florence took me under their wing to teach me about the oceanographic research they are conducting onboard the Dyson. At every station there is a specific order to how we sample. First the transducer, then the CTD, then numerous types of plankton nets, and then we end with the fishing trawl. The majority of the oceanographic data that they collect comes from the CTD (Conductivity, Temperature, Depth). The CTD is lowered over the side of the ship and as it slowly descends to about 100 meters it takes conductivity, temperature, and depth readings. Those readings go to a computer inside the dry lab where Jeanette is watching to record where the pycnocline is located.
The results from the CTD. Can you spot where the pycnocline is?
The pycnocline is a sharp boundary layer where the density of the water rapidly changes. The density changes because cold water is more dense than warm water and water with a higher salinity is more dense than water that is lower in salinity. So as the CTD travels down towards the bottom it measures warmer, less salty water near the surface, a dramatic change of temperature and salinity at the pycnocline, and then colder, saltier water below the pycnocline. Once Jeanette knows where the pycnocline is, she tells the CTD to collect water at depths below, above, and at the pycnocline boundary. The water is collected in niskin bottles and when the CTD is back on deck Florence and Jeanette take samples of the water to examine in the wet lab.
Filtering out the chlorophyll from the CTD water samples.
Back in the lab, Jeanette and Florence run several tests on the water that they collected. The first test that I watched them do was for chlorophyll. They used a vacuum to draw the water through two filters that filtered out the chlorophyll from the water. As the water from the CTD passed through the filters, the different sizes of chlorophyll would get stuck on the filter paper. Jeanette and Florence then collected the filter paper, placed them in labeled tubes, and stored them in a cold, dark freezer where the chlorophyll would not degrade. In the next couple of days the chlorophyll samples that they collected will be ran through a fluorometer which will quantify how much chlorophyll is actually in their samples.
Jeanette collecting water from the CTD.
Besides chlorophyll, Jeanette and Florence also tested the water for dissolved oxygen and nutrients like nitrates and phosphates. All of these tests will give the scientists a snapshot of the physical and biological characteristics of the Eastern Bering Sea at this time of year. This is very important to the fisheries research because it can help to determine the health of the ecosystem and return of the fish in the following year.
Personal Log
One of the high points for me so far on the cruise has been seeing and learning about all the new fish that we catch in the net. We have caught lots of salmon, pollock, and capelin. The capelin are funny because they smell exactly like cucumbers. When we get a big catch of capelin the entire fish lab smells like cucumbers…it’s so weird. We have also caught wolffish, yellow fin sole, herring, and a lot of different types of jellyfish. The jellies are fun because they come in all different shapes and sizes. We had a catch today that had some hug ones and everyone was taking their pictures with them.
Now that is a big jelly fish.
Today we also caught three large Chinook or king salmon. Ellen taught me how to fillet a fish and I practiced on a smaller fish and then filleted the salmon for the cook. What is even cooler was that at dinner we had salmon and it was the fish that we had caught and I had filleted. Fresh salmon is so good and I think the crew was happy to get to enjoy our catch.
The catch of the day was a 8.5 kg Chinook salmon.Salmon for dinner, filleted by Lindsay.
NOAA TEACHER AT SEA JASON MOELLER ONBOARD NOAA SHIP OSCAR DYSON JUNE 11 – JUNE 30, 2011
NOAA Teacher at Sea: Jason Moeller Ship: Oscar Dyson Mission: Walleye Pollock Survey Geographic Location: Gulf of Alaska Dates: June 17-18, 2011
Ship Data
Latitude: 52.34 N
Longitude: -167.51 W
Wind Speed: 7.25 knots
Surface Water Temperature: 6.6 Degrees C
Air Temperature: 7.1 Degrees C
Relative Humidity: 101%
Depth: 63.53 meters
All of the above information was found on http://shiptracker.noaa.gov. Readers can use this site to track exactly where I am at all times!
Personal Log
Welcome back, explorers!
It has been a very eventful 24 hours! We have started fishing, but have done so little that I will wait to talk about that in the next log. Tammy, the other Teacher at Sea, has not begun fishing yet, and as we will be writing the science and technology log together, I will save the fishing stories until she has had a chance to fish.
After turning in last night’s log, we managed to spot eight or nine humpback whales on our starboard side that appeared to be feeding at the surface. They were too far away to get any decent photos, but it was a lot of fun to watch the spouts from their blowholes tower up into the air.
Ten whale spouts rise in the distance.
This afternoon started off by dropping an expendable bathythermograph (from here on out this will be referred to as an XBT). The XBT measures the temperature and depth of the water column where it is dropped (there will be more on this in the Science and Technology section). I was told that I would be dropping the XBT this time, and was led off by Sarah and Abby (two of the scientists on board) to get ready.
The first thing I had to do was to get dressed. I was told the XBT would feel and sound like firing a shotgun, so I had to put on eye, ear and head protection. I was also put in a fireman suit to protect my body from the kickback, since I am so small. The XBT launcher is the tube in my hands.This is me launching the XBT. Why no smoke? All we actually needed to do was drop the device over the side. The whole shotgun experience was a prank pulled off by the scientists on all of the new guys. Their acting was great! When I turned towards Sarah at one point with the launcher, she ducked out of the way as if afraid I would accidentally fire it. I fell for it hook, line, and sinker.
However, the prank backfired somewhat. As the scientists were all laughing, a huge wave came up over the side of the ship and drenched us. I got nailed, but since I was in all of the gear, I stayed dry with the hem of my jeans being the only casualty. Sarah didn’t get so lucky. Fun times!
Sarah looking a bit wet.
Science and Technology Log
Today, we will be looking at the XBT (the expendable bathythermograph). Bathy refers to the depth, and thermo refers to the temperature. This probe measures the depth and temperature of the water column when it is dropped over the starboard side of the ship.
“Dropping” isn’t exactly the right phrase to use. We use a launcher that resembles a gun. See the photo below to get an idea of what the launcher looks like.
This is the XBT Launcher.The silver loop is the pin for the launcher. To launch the probe, we pulled the pin and flung out our arm. The momentum pushed the probe out of the tube and into the water below.
The probe.
The probe is connected to a length of copper wire, which runs continuously as the probe sinks through the water column. It is important to launch the probe as far away from the ship as possible, as the copper wire should never touch the ship. If the wire were to touch the ship, the data feed back to the ship would be disrupted and we would have to launch another probe, which is a waste of money and equipment. The survey technician decides to cut the wire when he/she has determined that sufficient data has been acquired. This normally occurs when the probe hits the ocean floor.
This is a quick and convenient way to collect data on the depth and temperature of the water column. While the ship has other methods of collecting this data (such as a Conductivity, Temperature, and Depth (CTD) probe), the XBT is a simpler system that does not need to be recovered (as opposed to the CTD).
A CTD
Data collected from the most recent XBT.
Latitude: 53.20 degrees N
Longitude: 167.46 degrees W
Temperature at surface: 6.7 degrees C
Temperature at bottom: 5.1 degrees C
Thermocline: 0 meters to 25 meters.
The thermocline is the area where the most rapid temperature change occurs. Beneath the thermocline, the temperature remains relatively constant.
Today’s reader questions come from James and David Segrest, who are two of my students in Knoxville Zoo’s homeschool Tuesday classes!
1. Did pirates ever travel the path you are on now? Are there any out there now?
A. As far as I know, there are no pirates currently operating in Alaska, and according to the scientists, there were not any on the specific route that we are now traveling. However, Alaska does have a history of piracy! In 1910, a man named James Robert Heckem invented a floating fish trap that was designed to catch salmon. The trap was able to divert migrating salmon away from their normal route and into a funnel, which dumped the fish off into a circular wire net. There, the fish would swim around until they were taken from the trap.
Workers remove salmon from a fish trap in 1938. Historic Photo Courtesy of the U.S. Fish & Wildlife - Fisheries Collection - Photographer: Archival photograph by Mr. Sean Linehan, NOS, NGS.
For people who liked eating fish, this was a great thing! The salmon could be caught quickly with less work, and it was fresh, as the salmon would still be alive when taken from the trap. For the traditional fisherman, however, this was terrible news. The fishermen could not compete with the traps and found that they could not make a living. The result was that the fishermen began raiding the floating traps, using any means possible.
A barge of salmon going to a cannery. Fishermen could not compete with traps that could catch more fish. Historic Photo Courtesy of the U.S. Fish & Wildlife - Fisheries Collection -Photographer: Archival photograph by Mr. Sean Linehan, NOS, NGS
The most common method used was bribery. The canneries that operated the traps would hire individuals to watch the traps. Fishermen would bribe the watchers, steal the fish, and then leave the area. The practice became so common that the canneries began to hire people to watch the trap-watchers.
2. Have you seen any sharks? Are there any sharks that roam the waters where you are traveling?
Hi James and David! Here is your shark! It's a Pacific Sleeper Shark.The shark in the netAnother image of the shark on the conveyor belt.
This is a Pacific Sleeper Shark. It is called a sleeper shark as it does not appear to move a great deal, choosing instead to glide with very little movement of its fins. As a result, it does not make any noise underwater, making it the owl of the shark world. It hunts much faster fish (pollock, flounders, rockfish) by being stealthy. They are also known to eat crabs, octopus, and even snails! It is one of two animals known to eat giant squid, with the other one being sperm whales, although it is believed that these sharks probably scavenge the bodies of the much larger squid.
The other shark commonly seen is the salmon shark. Hopefully, we will catch one of these and I will have photos later in the trip.
NOAA Teacher at Sea: Story Miller NOAA Ship: Oscar Dyson
Mission: Summer Pollock III
Geographical Area: Bering Sea
Date: August 1, 2010
Launching the XBT
Time: 1233 ADT
Latitude: 60°51N
Longitude:179°11W
Wind: 17 knots (approx. 19.6 mph or 31.5 km/h)
Direction: 171° (S)
Sea Temperature: 9.9°C (approx. 49.8°F)
Air Temperature: 12.8°C (approx. 55.0°F)
Barometric Pressure (mb): 1009
Wave Height 2-3 feet
Swell Height 4-6 feet
Scientific Log:
Think about your morning routine from the moment you wake up to just after eating breakfast. Now imagine spending that morning on a boat in the middle of the Bering Sea. Perhaps you take a shower or wash your face and hopefully brush your teeth. Where does the water come from? Where does the waste water go? I bet at some point you will use the bathroom (Hey, it’s a fact of life and everybody does it!). Where does that waste go? How is it processed? I also bet that at some point you turned on the light. How does a boat get its electricity?
The Oscar Dyson has a truly remarkable system that allows a crew of up to 39 live on the ship for as long as we have food and fuel! The fuel used is diesel and the diesel is converted into electricity through the engine, which turns the generator and the generator makes AC power. A rectifier ridge turns the AC power into DC power and the DC power runs to the shaft which is able to turn the propeller. However not all the power goes to DC power. The rest is turned into AC power so that we can use lights, heaters, fans, and the ovens in the galley.
Below the deck of the ship is where the engineers maintain all the components that make the ship function.
The Machines:
The main shaft (what turns the propeller on the ship)
Because we would not be able to go anywhere without fuel, let’s start with it. The fuel goes from the fuel tank to a primary filter and then through a secondary filter to clean the fuel. The fuel then travels to the fuel pump which transfers it to the injector and the injector sends it to the engine.
The centrifuges that clean the fuel.
Whatever fuel is not used is returned to a storage tank where it will wait until we need it again. Because fuel can become dirty when it sits, and dirty fuel is not good for engines, the old fuel is run through a centrifuge (a device that spins and uses centrifugal force to separate mixtures) to become purified. As you can see in the picture, there are two centrifuges because it is important to have a backup in case of a breakdown. One is currently running for the month of July and the other will run for the month of August. We have this alternating pattern because we want to make sure there is even wear on each.
Access hatch to the waste oil storage. Entering confined spaces are dangerous as noted by the bolted entry. Special protective materials, a work plan, and an initial safety test must be in place prior to entry
Periodically, the ship requires an oil change and the waste oil from machines such as the crank case, winches, and hydraulics are placed in a storage tank. Because it costs a considerable amount of money to haul waste fuel, the ship has a method for disposing it. From this waste oil storage tank, it is pumped up to the incinerator where it is burned.
The ship will also obtain oily water from locations such as the bilges and that water is recycled by going through the Oily Water System (OWS) and currently it is able to clean the water to 15ppm (parts per million) of oil to water. After the purification it is released into the ocean. We are currently in the process of installing another filtration system that will run the 15ppm concentration and reduce the contaminants to 5ppm and possibly even 3ppm. The oil that is extracted from the water is put into the waste oil storage tank for future incineration.
Engineering Control Room
As stated earlier, all the machinery, including the coffee maker, is maintained by the engineers. In the control room the engineers are able to monitor all functions of the ship. If needed, they could even take away the power from the bridge (where the NOAA Corps officers control the ship) and drive the ship from underneath! So, if you really want to be in control…
Sanitation:
Some may wonder what we do with all of the garbage we collect on the ship. For example, where does all the uneaten food go? What about all the paper waste from used cups, napkins, and wrappers? In the mess hall, there are two garbage bins, one to scrape uneaten food and the other for paper. Because food is biodegradable, that bin is tossed overboard. The paper waste is sent to the incinerator to be burned. I am told that the incinerator gets hot enough that if a soup can was placed inside and incinerated, it would appear to look normal after the incineration, except once you touch it, it crumbles into dust!To get clean drinking water, we pump the salt water from the ocean into a desalination unit (a distiller). The distilled water is then sent to a 10,000 gallon holding tank. When water is needed, it is pressurized which, like in your house, sends it to the faucets, drinking fountains, and shower. Perhaps you have heard of the pens using UV light to purify water when you are camping. Well, right after the water is pressurized the boat has a large UV Pen to kill any additional microbes that might be inhabiting the water.
Marine Sanitation Device
From the toilet, the waste material is pulled down by a vacuum and travels through a pipe to the Marine Sanitation Device (MSD) tank. All the waste, including what we call “gray water” which basically is waste water from the shower and the sink, is agitated with an aroator. Solid waste will sink to the bottom of the tank where it is ground to fine particles. Oddly enough the grinder is also responsible for the vacuum in the sewage line via the eductor. The dirty water mixture is then sent through the chlorinator and is stored in the chlorination tank. When the water rises to a certain point, a sensor signals the pump to send the chlorinated water over the side of the boat.Cool fact! On other ships in the past, the catch water in the toilets was salt water (the Oscar Dyson uses fresh water). Because the water in the toilets did not need to be distilled, little bioluminescent organisms would sit inside. The thrilling activity is that when a person would flush the toilet in the dark, the organisms would become agitated and glow. Therefore, in your toilet, you could have your own light show with each flush!
Personal Log:
Squid
Today we processed one batch of fish. The odd part to this scenario was that we caught a group of Pacific Herring. We measured, weighed, and extracted stomach samples as it is equally important to gather data about other fish we catch. The internal body structure of a Pacific Herring is very different from that of a Walleye Pollock and so I had the opportunity to dissect and study a different kind of fish. Leftover critters from the trawl that occurred last night while I was sleeping also appeared in the catch – tiny jellyfish, squid, and shrimp – and I spent some time sorting them out. Tonight, our chef is cooking up a few of the herring so we can see what they taste like. Another highlight to working with the herring is that I was challenged to locate and extract the otoliths. The otoliths of Pacific Herring are much smaller than those of the Walleye Pollock. To provide an idea, imagine clipping your pinky toenail. The clipping would be just a little larger than the otolith! Otoliths of pollock are a little less than one centimeter long and 1/2 of one centimeter wide.
Jellyfish
Today we crossed the 180° line of Longitude and entered the future, putting me a day ahead of the United States. Currently our transect has placed us near Cape Nevarin, Russia and unfortunately it is too foggy outside to see land. Because I have crossed the dateline, I will receive the Order of the Golden Dragon, a certificate proving my adventure across the line!I am exceptionally excited for dinner tonight as we are having King Crab legs, prime rib, mashed potatoes and gravy, and of course, some herring! With Ray as our chef, it is evident that nobody goes hungry! Today he constructed a shortcake in the shape of the Oscar Dyson, decorated it, and set aside a bowl of strawberry sauce. I would have taken a picture but by the time I finished processing the herring, the cake ships were in fatal condition for sailing but I feel the crew are quite satisfied!
Something to Ponder:
I decided that it was important to inquire what it took to be an engineer on the boat. After talking with a few members of the crew who had been doing this line of work for a long time, I was loaded with valuable insight to pass along to my readers.
According to the engineers, the best way to guarantee a well-paying job on a boat and allow one to have more options available would be to attend a maritime school because graduates will walk onboard with an officers ticket. While college is expensive, consider this: If you attend the US Merchant Marine Academy (USMMA), your college is paid for as it is one of the five US service academies. www.usmma.edu
However, because admission is difficult, if you were to attend a maritime academy, you could potentially have a situation similar to one of our engineers on board. He attended Maine Maritime Academy for four years and earned a Bachelors of Science in Engineering. Additionally, within six months of working onboard a ship with his credentials, he had ALL of his student loans paid for! Most college students in the US spend approximately five years paying off their student loans!
While a maritime academy would be ideal, I asked the engineers of other ways one could obtain an engineering/mechanic job on a ship. They shared that there were 2-year schools available but the largest drawback to that path is that upon graduation, you would have some skills but would not be fully licensed. One rule of thumb that I have learned over the years, and the engineers echoed this, is the key to having choices in your job is to become as versatile as possible.I then asked the engineers if there were any other ways to get a job on a boat and they mentioned that one could attend a union school and learn a trade such as in refrigeration or mechanics. Keep in mind though, that person would be unlicensed and not have as many choices available to them.
I also asked the engineers what subjects in school they thought were the most important to learn. The first subject mentioned was mathematics but they brought up a very important concept: “It’s not necessarily how much math you take, but how well you understand the math.” Think of a student who aces the test and then forgets everything afterward. In other words, it would be great if a student made it to Calculus in high school but if he or she doesn’t fully understand the processes behind the algebra, that student will have difficulty in his or her engineering occupation. The engineers also shared that trigonometry was essential.
Regarding the sciences, for engineering, it was highly recommended that students wanting to get off on the right foot should take chemistry, physics, and biology.
However, one of the most important subjects they mentioned that may surprise some readers is English Composition because “You must have the ability to express yourself effectively and communicate with the people you work with everyday.” The engineers shared that, for example, they often would have to write reports and if they needed a part, the engineers would need to write to a supervisor and provide reasons to prove why they would need a part. “The better you are at communicating, the farther you will be able to go with your job and get what you want.”
So, in closing, the next time you think, “Geeze, why do I need to learn this equation and how to use it in this silly word problem?” or, “Why do I need to write this paper about persuading my English teacher that peanut butter and jelly sandwiches are the best?” remember this: Your teachers really are not torturing you and really, are simply training you to develop the skills you will need to utilize in your job and in adulthood. The more advantage you take of this training, the more versatile and successful you will become. Ultimately though, it’s up to you to make that move!For more information a valuable website is:http://www.omao.noaa.gov/about.html
NOAA Teacher at Sea Mechelle Shoemake Onboard NOAA Ship Oregon II June 19 – 30, 2010
Mission: SEAMAP Groundfish Survey Geographical Area of Cruise: Northwestern Gulf of Mexico Date: Sunday, June 27, 2010
Weather Data from the Bridge Time: 0700 hours (07:00am) Position: Latitude = 28.80.02 N; Longitude = 090.20.40 W Present Weather: partly cloudy Visibility: 8 nautical miles Wind Speed: 8 knots Wave Height: 3 foot swells Sea Water Temp: 29.8 degrees Celsius Air Temperature: Dry bulb = 27.9 degrees Celsius; Wet bulb = 25.5 degrees Celsius
Here I am measuring and weighing the fish.
Science and Technology Log
We are on twelve hour shifts while on the Oregon II. That means that we have two crews of scientists that work around the clock taking fish, plankton, and water samples. My shift begins at 12:00 noon and ends at midnight. Our first shift began on Sunday. We had finally reached our first station for study, so we took over for the first set of scientists. They had just finished a trawl and had separated the fish.
Here I am measuring and weighing the fish
We finished weighing and measuring the fish. Next on the agenda was a fire and abandon ship drill. We had to “muster” to our stations for a head count during the fire drill. Next, the alarm sounded for the abandon ship drill. We all had to get our survival suits and meet on the top deck.
As soon as the drill was over, we were able to get back to work. we first did a CTD test, which stands for conductivity, temperature, and density. This fancy machine tests these variables of ocean water at different depths. We took water samples from the bottom of the ocean, in the middle, and on the surface of the water column. This is a very important sampling because it will help to determine if the shrimping and fishing waters can be opened back up since the Deepwater Horizon/BP oil spill.
During the safety drill, I donned my survival aute, also called a Gumby suit!I’m assisting in getting the CTD ready for deployment
We then had to take a plankton samples. This is done buy using a plankton net called a Neuston net. it is very fine woven net that catches all of the small fish and other animals that we label as plankton. This was amazing to see. The net caught “floating nursery,” a plant called sargassum. Many fish lay their eggs in this floating grass. Sea turtles also use it as a resting ground. We gathered all the plankton and preserved it for further testing. Sad to say, we also picked up some tarballs in our plankton net. This is not a good sign.
We soon did a trawl with the shrimping nets. This was very interesting to see what we caught. You never know what you might catch when you drag the ocean floor with a net. I never realized how many different species of fish there are. We caught some very nice sized brown shrimp. We had to count, weigh, and preserve all the fish and other critters.
This is a close up of the Neuston net.I’m helping sort the catch. Those are squid I’m holding up.
Personal Log
I really admire the NOAA employees. They all work very hard for us. Our ship is performing a very important job by determining whether areas of the Gulf will be safe for fishing again. These men and women are gone from their families for extended periods of time and stay at sea for long voyages. I am enjoying my stay on the Oregon II, but I have to admit that I am still trying to grow my “sea legs”.
Bringing in the nets requires attention and teamwork.
Weather Data from the Bridge
SW wind 10 knots
Wind waves 1 or 2 feet
17 degrees Celsius
Science and Technology Log
In Science we learn that a system consists of many parts working together. This ship is a small integrated system-many teams working together. Each team is accountable for their part of the hake survey. Like any good science investigation there are independent, dependent and controlled variables. There are so many variables involved just to determine where and when to take a fish sample.
Matt directs the crane to move to the right. Looks like some extra squid ink in this haul.
The acoustic scientists constantly monitor sonar images in the acoustics lab. There are ten screens displaying different information in that one room. The skilled scientists decide when it is time to fish by analyzing the data. Different species have different acoustical signatures. Some screens show echograms of marine organisms detected in the water column by the echo sounders. With these echograms, the scientists have become very accurate in predicting what will likely be caught in the net. The OOD (Officer of the Deck) is responsible for driving the ship and observes different data from the bridge. Some of the variables they monitor are weather related; for example: wind speed and direction or swell height and period. Other variables are observed on radar like the other ships in the area. The topography of the ocean floor is also critical when nets are lowered to collect bottom fish. There are numerous sophisticated instruments on the bridge collecting information twenty four hours a day. Well trained officers analyze this data constantly to keep the ship on a safe course.
Here come the hake!
When the decision to fish has been made more variables are involved. One person must watch for marine mammals for at least 10 minutes prior to fishing. If marine mammals are present in this area then they cannot be disturbed and the scientists will have to delay fishing until the marine mammals leave or find another location to fish. When the nets are deployed the speed of the boat, the tension on the winch, the amount of weight attached will determine how fast the nets reach their target fishing depth. In the small trawl house facing the stern of the ship where the trawl nets are deployed, a variety of net monitoring instruments and the echo sounder are watched. The ship personnel are communicating with the bridge; the deck crew are controlling the winches and net reels and the acoustic scientist is determining exactly how deep and the duration of the trawl. Data is constantly being recorded. There are many decisions that must be made quickly involving numerous variables.
Working together to sort the squid from the hake.
The Hake Survey began in 1977 collecting every three years and then in 2001 it became a biannual survey. Like all experiments there are protocols that must be followed to ensure data quality. Protocols define survey operations from sunrise to sunset. Survey transect line design is also included in the protocols. The US portion of the Hake survey is from approximately 60 nautical miles south of Monterey, California to the US-Canada Border. The exact location of the fishing samples changes based on fish detected in the echograms although the distance between transects is fished at 10 nautical miles. Covering depths of 50-1500 m throughout the survey. Sampling one species to determine the health of fish populations and ocean trends is very dynamic.
Weighing and measuring the hake.
Personal Log
Science requires team work and accountability. Every crew member has an integral part in making this survey accurate. A willing positive attitude and ability to perform your best is consistently evident on the Miller Freeman. In the past few days, I’ve had the amazing opportunity to assist in collecting the data of most of the parts of this survey, even launching the CTD at night from the “Hero Platform” an extended grate from the quarter deck.
Stomach samples need to be accurately labeled and handled carefully.
Before fishing, I’ve been on the bridge looking for marine mammals. When the fish nets have been recovered and dumped on the sorting table, I’ve sorted, weighed and measured fish. For my first experience in the wet lab, I was pleased to be asked to scan numbers (a relatively clean task) and put otoliths (ear bones) into vials of alcohol. I used forceps instead of a scalpel. Ten stomachs are dissected, placed in cloth bags and preserved in formaldehyde. A label goes into each cloth bag so that the specimen can be cross referenced with the otoliths, weight, length and sex of that hake. With all the high tech equipment it’s surprising that a lowly pencil is the necessary tool but the paper is high tech since it looks regular but is water proof. It was special to record the 100th catch of the survey.
Removing the otolith (ear bone) with one exact incision. An otolith reminds me of a squash seed or a little silver feather in jewelry.Each barcoded vial is scanned so the otolith number is linked to the weight, length and sex data of the individual hake.
Questions for the Day
How is a fish ear bone (otolith) similar to a tree trunk? (They both have rings that can be counted as a way to determine the age of the fish or the tree.)
The CTD (conductivity, temperature and depth) unit drops 60 meters per minute and the ocean is 425 meters deep at this location; how many minutes will it take the CTD to reach the 420 meter depth?
Think About This: The survey team directs the crane operator to stop the CTD drop within 5 meters of the bottom of the ocean. Can you think of reasons why the delicate machinery is never dropped exactly to the ocean floor? Some possible reasons are:
The swell in the ocean could make the ship higher at that moment;
An object that is not detected on the sonar could be on the ocean floor;
The rosetta or carousel holding the measurement tools might not be level.
Launching the CTD is a cooperative effort. The boom operator works from the deck above in visual contact. Everyone is in radio contact with the bridge since the ship slows down for this data collection.
