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 30, 2007
Mesh netting in the dredge
Weather Data from the Bridge
Air Temperature: 17.5° C
Sea Temperature: 18.6° C
Relative Humidity: 100 %
Barometric Pressure: 1014.8 millibars
Wind Speed: 3.62 knots
Water Depth: 65.3 meters
Conductivity: 43.45 mmhos
Salinity: 32.03 ppt
Science and Technology Log
I can’t believe it’s already been a week already since we left from Woods Hole, MA. I’m still getting a hang of the time schedule, but it’s working out okay. The weather has been beautiful. The staff is great—I’ve learned so much from them. The food is delicious, too! Today’s focus will be on the dredge. This is a metal frame with a metal ringed and meshed net that we use to dredge or scoop the sea bottom in hopes of finding our prize catch, sea scallops. The bag is about 8 feet wide with 2” rings and mesh netting. The mesh netting, called a liner, is in the dredge to ensure catching of the smaller scallops as well as the other species that coexist with the scallops. The dredge is lifted, put into the water, and dragged using a motorized gantry with a block and tackle system. The dredge is towed for 15 minutes at each station. The depths for this trip have been ranging from 29 meters to 112 meters. Sea Scallop dredge surveys have been conducted by the National Marine Fisheries Services since 1975.
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 28, 2007
Here I am measuring a skate using the FSCS system.
Weather Data from the Bridge
Air Temperature: 21.4° C
Sea Temperature: 19° C
Relative Humidity: 100%
Barometric Pressure: 1013.6 millibars
Wind Speed: 10.78 knots
Water Depth: 62.4 meters
Conductivity: 44.76 mmhos
Salinity: 32.58 ppt
Science and Technology Log
I am completely exhausted! We had about 12-14 stations almost back to back last night. Down on your knees picking through the sort to find scallops and fish to back bending of lifting up full baskets and cleaning the deck, I’m tired. It was loads of fun, though. We went from collections of sand dollars to big scallops, quahogs (clams), flounders, big sea stars, and sticky, slimy skates. When the scallops, flounders and skates come in, we weigh them on a scale and then measure their length and count them using the Fisheries Scientific Computer System (FSCS). It’s pretty cool how it works. You lay the species on the electronic board, and it gets measured by us using a magnetic stick to mark it. Once marked, the measurement goes right into the computer as well as counts it. One station, we counted 788 scallops! That is a lot, but they say there’s more where that came from!
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.
