NOAA Teacher at Sea
Susie Hill
Onboard NOAA Ship Albatross IV July 23 – August 3, 2007
Mission: Sea Scallop Survey Geographical Area: North Atlantic Ocean Date: July 27, 2007
Weather Data from the Bridge
Air Temperature: 21° C
Set Temperature: 22° C
Relative Humidity: 100 %
Barometric Pressure: 1017.1 millibars
Wind Speed: 3.76 knots
Water Depth: 67.0 meters
Conductivity: 45.75 mmhos
Salinity: 32.13 ppt
Science and Technology Log
The weather has been very nice, sunny, and calm. Conditions were so clear last night that we could see fireworks far off into the distance. I’m getting into the routine of all of the stations- sorting for fish and scallops, weighing, measuring the length (or in scallop terms, shell height), counting starfish, and cleaning off the deck.
Today’s focus is on the CTD meter that measures conductivity, temperature, and depth. This is the instrument that they use to determine the conditions of the water. It is lowered down to about 5-10 meters from the ocean floor about twice in a shift (12 hours). Some other results they also receive are pressure and salinity levels. These measurements are collected at the surface as well as at the bottom. Once they receive all of the data, it is loaded into a computer and turned into a very colorful graph. Scallops like to live in water temperatures of < 20° C and in water depths of up to 200 meters south of Cape Cod (Dvora Hart, WHOI, 2002).
NOAA Teacher at Sea
Susie Hill
Onboard NOAA Ship Albatross IV July 23 – August 3, 2007
Mission: Sea Scallop Survey Geographical Area: North Atlantic Ocean Date: July 26, 2007
Sunfish (Mola mola)
Weather Data from the Bridge
Air Temperature: 20.6° C
Sea Temperature: 22.6 ° C
Relative Humidity: 97%
Barometric Pressure: 1022.1 millibars
Wind Speed: 3.36 knots
Water Depth: 57.2 m
Conductivity: 46.15 mmhos
Salinity: 31.56 ppt
Science and Technology Log
From noon to midnight, we go from being hot under the shining sun searching for the treasure of scallops in the collected pile to sitting under the beautiful moonlight shining across the vast ocean waiting for the next tow. It’s wonderful no matter how you look at science!
Today, I got to start up the starfish study. We are counting starfish from the sort to figure out the abundance and distribution of the Asterias sp. and Astropecten sp. in the researched area. Depending on the location of the station will determine how many of sea stars you have. The first station, we had loads of starfish! The starfish are randomly collected off of the remaining pile after everyone has been through it for their studies. Out of 4.5 liters (about 5 large handfuls), I counted 340 Astropecten sp. I can’t imagine how many there really were! With the passing of the stations from each night, the majority species of the pile has shifted from starfish to sand dollars. I’m glad I don’t have to count those because there’s so many of them. Sand dollars are part of the echinoderm family with the sea stars. I always thought that they were white like you buy them in the beach souvenir shops, but they’re a dark purple color when they’re alive. Pretty cool! I’ve got lots of samples to bring home!
With being in the middle of the ocean, you also get to see the big marine life! It was kind of gross, but amazing at the same time! We thought it was a dead whale, but it ended up being a basking shark that has been dead for maybe a week. You could see the decaying skin, bloated belly, and the now showing gill rakers (the cartilaginous structures that filter food and sediment out of the gills when the shark eats). We also saw a sunfish (Mola mola)! We show a mini-movie of one of them as you’re going up the moving escalator at Nauticus, but it is so awesome seeing it in real life! It looks like a whale that’s been flattened. So cool!
NOAA Teacher at Sea
Claude Larson
Onboard NOAA Ship Albatross IV July 23 – August 3, 2007
Mission: Sea Scallop Survey Geographical Area: North Atlantic Ocean Date: July 26, 2007
Weather Data from the Bridge
Air Temperature: 21.9º C
Water Temperature: 22.6 º C
Relative Humidity: 91%
Wind Speed: 8 knots
Wind Direction: S
Melissa Ellwanger (left) and Stacey Etheridge check the results for PSPs.
Science and Technology Log
The ALBATROSS IV is well underway with the second leg of its Sea Scallop Survey for this year. After several tows we have collected, counted, weighed and measured not only sea scallops but, several types of fish, crabs and starfish. As a teacher, I would like to focus on the application of some the science that is going on here on the ship. Specifically, I want to explain the work of two scientists on board Stacey Etheridge and Melissa Ellwanger who work at the FDA, Food and Drug Administration.
Sea scallops are studied by NOAA because of their importance commercially. People enjoy them baked, fried, sautéed and served up hot. In other parts of the world, Europe and Asia, certain parts of the scallops are valued commercially as a food source. These parts are the gonads and viscera, or internal organs and membranes. Last year the FDA had to close certain fishing areas were closed to bivalve molluscan harvesting because PSPs, paralytic shellfish poisoning toxins were too high for human consumption. These toxins accumulate in filter feeders and thus harvesting was closed to organisms such as surfclams, mussels and quahogs. Sea scallops could still be harvested for the adductor muscle only. Toxins in scallops, however, build up in the gonads and viscera. If a person were to eat these affected seafoods they could actually become paralyzed and it could be fatal unless the victim receives respiratory support.
The toxins are produced by certain algae that are found in the environment with the scallops. The toxins vary in potency and can actually become stronger after the scallops eat them by interacting with the digestive processes of the sea scallop. This leads us to Stacey and Melissa’s experiment. At each collection of sea scallops, they collect twelve random sea scallops to test. They dissect the scallop and separate the gonad and viscera and test them separately. They puree the organs, add extraction chemicals, filter them and then test the liquid that they filter from the organs on little test plates that look like test strips people use when they are trying to find out if they are pregnant.
The preliminary results from some of the samples they have collected have been positive for PSPs. This raises the question about whether or not those collected scallops can be sold for all of their parts or just the meaty section. The work Stacey and Melissa are doing with NOAA and the FDA is an excellent example of applied science that benefits people and helps improve one of their food sources.
NOAA Teacher at Sea
Susie Hill
Onboard NOAA Ship Albatross IV July 23 – August 3, 2007
Mission: Sea Scallop Survey Geographical Area: North Atlantic Ocean Date: July 25, 2007
Weather Data from the Bridge
Air Temperature: 20.8 ° C
Sea Temperature: 21.8 ° C
Relative Humidity: 93%
Barometric Pressure: 1022.4 millibars
Wind Speed: 5 knots
Water Depth: 58 meters
Conductivity: 44.91 mmhos
Salinity: 31 ppt
Science and Technology Log
It’s the morning after my first shift, and surprisingly, I still have energy! It was so much fun! It took us about 8 hours to get to our first tow station, and then we went right to work. At each tow station, the dredge is emptied out onto the deck for us to sort. In addition to the standard sampling to assess the stock, scientists request certain species samples for additional research before each cruise. The samples that are being pulled this trip are scallops, skates, hake fish, starfish (some of us call them sea stars), and monkfish (or goosefish). So, we pull these out of the catch and the rest is thrown back out to sea. It’s a race from there to get all of the research done before the next tow. The scientists everywhere (including me!) are weighing , dissecting, and recording the data into the FSCS (Fisheries Scientific Computer System). It’s awesome!
One of my stations was to help take the data on the sea scallops. We measured the gonad, meat, and viscera (pretty much everything else in the shell) weights of 5 randomly chosen sea scallops to determine the sex and shell height/meat weight relationships. The shells will be measured back at Woods Hole to determine the age. Do you know how scientists determine the age of a scallop? They count the rings on the outer shell just like you would to determine the age of a tree. We also collected these samples to help with a study being done by Scientist Stacey Etheridge and Melissa Ellwanger from FDA (Food and Drug Administration) to determine PSP (paralytic shellfish poisoning) levels. They are also testing for Alexandrium sp., a dinoflagellate phytoplankton, in the water sample that can also cause PSP in humans.
It is pretty cool that the scientists let us help out at the different stations so we could get a hand in everything that is going on. When I came on, I thought that we were only going to be doing one study- studying just scallops. It turns out that we get to experience so much more!
NOAA Teacher at Sea
Claude Larson
Onboard NOAA Ship Albatross IV July 23 – August 3, 2007
Mission: Sea Scallop Survey Geographical Area: North Atlantic Ocean Date: July 25, 2007
Weather Data from the Bridge
Air Temperature: 21.7° C
Water Temperature: 22.9
Relative Humidity 93%
Wind Speed: 10 knots
Wind Direction: SE 120
Jakub Kircun teaches Claude Larson how to insert the probe that measures inclination in the top of the dredge equipment.
Science and Technology Log
Today was the beginning of our first 12 hour watches. The tows were relatively well spaced which allowed for ample clean up time between tows and even for a little down time as we steamed for over an hour and I have a few minutes to write this log entry.
As I learn the skills needed to be useful on the Scallop Survey, I want to give you an idea of how a tow is carried out. The bridge generally gives us a ten minute alert before a tow over the all call system. From that point we can finish up what we are doing and prepare for the tow. A crew member operates a huge winch and block and tackle that moves a thick metal cable. The cable is attached to a large metal hook that is attached to an 8 foot wide dredge net. The net is raised from the aft deck of the ship and put in the water. The dredge net is then towed for fifteen minutes and then lifted onto the deck. At this time, a probe that measures inclination is inserted in the dredge rigging and information about the collection of the tow is recorded and loaded onto another computer for later use.
While the probe is being read, someone takes a picture of the pile of organisms on deck with a small whiteboard with important information. This information includes the station number, stratum and tow number, as well as whether this area is open or closed to commercial fishing.
The watch crew then brings baskets and buckets over to the edges of the pile and kneels on cushions to sift through the collected material. We sort the collection into sea scallops, fish and, on each third tow, we also collect crabs. After a few minutes we shift areas and continue to look for certain animals, this helps us to make sure we have found all of the organisms we are looking for. The fish are then further sorted by species. The watch chief weighs each separate species and records that information on the FSCS, Fisheries Scientific Computer System. There are three FSCS stations and we all get to work at one of them. The computer allows you to take the scallop or fish and lay it on a long board. The organism is held along the front panel of the system and a magnet is placed at the other end. The magnet causes the computer to automatically record the length of the scallop or fish. From there some of the scallop shells are cleaned for a scientist back in Woods Hole, Dvora Hart, and carefully labeled and placed in a cloth bag. Some of the scallops are also dissected for an FDA study on PSPs, paralytic shellfish poisoning. When ever we catch a monkfish, also known as a goosefish, one of the scientists on the watch crew dissects it for vertebrae for a study they are doing on aging the fish and its reproductive stage.
Once all the organisms are measured, weighed, dissected or cleaned, the remainder of the pile is shoveled in large baskets and thrown back into the ocean. Each basket and bucket is rinsed as is each FSCS station. If another tow is arriving shortly, the watch crew prepares for repeating this process. The steps happen in relatively that order, however they also occur in a sort of unison and the watch crew starts to form a rhythm. The watch chief and veteran crew members help any of the new folks on board, which is great since we are sometimes unsure what to do next or how to do a new task. The old saying of many hands make light work definitely applies here. With each tow there are surprises to dig for. Sometimes you get to see large egg cases or beautiful shellfish and unusual fish.
With all of this said, the all call has just given us a ten minute to station call. I must get ready for whatever treasures will be brought up with this collection.
