Donna Knutson: The Absolutely Amazing Atlantic Sea Scallop, June 12, 2016

NOAA Teacher at Sea Donna Knutson
Aboard R/V Hugh R. Sharp
June 8 – June 24, 2016

 

2016 Mission: Atlantic Scallop/Benthic Habitat Survey
Geographical Area of Cruise: Northeastern U.S. Atlantic Coast
Date: June 12, 2016

Mission and Geographical Area: 

The University of Delaware’s ship, R/V Sharp, is on a NOAA mission to assess the abundance and age distribution of the Atlantic Sea Scallop along the Eastern U.S. coast from Mid Atlantic Bight to Georges Bank.  NOAA does this survey in accordance with Magnuson Stevens Act requirements.

Weather Data from the Bridge

Latitude:  40 26.375 N
Longitude:  68 19.266 W
Clouds: overcast
Visibility: 5-6 nautical miles
Wind: 21 knots at cruise speed of 4 knots
Wave Height: 4-6 occasional 8 ft.
Water Temperature:  56 °F
Air Temperature:  70 °F
Sea Level Pressure:  29.7 in of Hg
Water Depth: 100 m

Science and Technology Log

! TAS 010There are four types of scallops that are found around the United States.  The Sea Scallop is the largest and found primarily along the Eastern coast.  Therefore, it is called the Atlantic Sea Scallop.  Bay scallops are smaller, found closer to shore and are not usually harvested.  The Calico mollusk is the smallest and rare, and is primarily located around the coast of Florida.  The Icelandic scallop is also occasionally sighted around the United States.

The Atlantic Sea Scallop Placopecten magellanicus  is a deep sea bivalve mollusk.  It has a smooth shell and edges.  Young scallops have a pink/red color with darker stripes radiating outward form the hinge. The older sea scallop is more orange in coloration and may fade into white.  Photoreceptive eyes along their pale pink mantle, allow the scallop to sense changes in light allowing it to protect itself from possible dangers such as incoming predators.

Alantic sea scallop

Atlantic sea scallop

Some mollusks are hermaphroditic meaning they have both sex organs in the same animal, but the Atlantic sea scallop has two distinct sexes.  It is impossible to tell what the sex of a scallop is from its outward appearance.  When looking inside at the gonads it is easy to detect.  The male gonads are creamy white and the female gonads are pink/red in color.

The female can reproduce after they are one-year-old, but four year olds release many more eggs.  The older scallop may emit one to two hundred seventy million eggs at one time.  Spawning occurs twice a year, once in the spring and another in the fall.  Males will release their sperm into the water where the eggs have been released, and then the fertilized egg sinks to the bottom of the ocean to develop in groupings called beds.

Adult scallops will filter feed on phytoplankton and microscopic zooplankton.  The immature larva are filter feeders as well, but can also absorb nutrients though their tissues.

Atlantic sea scallops play an important role in the ecosystem as they become food for other animals such as starfish, crabs, lobsters, snails, and fish such as cod, American plaice, wolfish, and winter flounder.

Sources:

Wikipedia, May 30, 2016

US Atlantic Sea Scallop, March 31, 2013

 

Personal Log

Leg III of the Atlantic Scallop/Benthic Habitat Survey started out a bit rough, bad weather came in from Hurricane Collin and caused a few delays.  The lead scientist Tasha O’Hara decided to push back the departure times in hope of gentler seas.

We set sail on Thursday June 12, 2016 around 7 p.m. from NOAA’s Northeast Fisheries Science Center in Woods Hole.  The Sharp started the third leg of four on the scallop survey.  The last leg will end on June 24, 2016.  The survey team will use a camera to take pictures of the bottom called a HabCam, which stands for Habitat Mapping Camera, and also dredge the ocean bottom periodically for physically counting and measuring specimens.

I have been allowed to participate in the driving of the HabCam and also the sorting, measuring and recording of animals brought up from the dredges.  My blogging got a bit behind as I was trying to immerse myself in the new experiences when the sea sickness hit.

Goosefish

Donna holds a Goosefish

I did not get sick once on the last month long experience, but conditions here are a bit different.  The captain of the Sharp, James Warrington, explained the gyre (oceanic current pattern) is unique here.  We are in a cruising within circular gyre and with weather conditions forcing high waves into the flat bottomed boat, we are getting a lot of motion.  So, yes, I now know what sea sickness is like.  Today the wind has died down a bit so the waves are not as high, and I feel much better.  I have been placed on the midnight to noon crew so that has been an adjustment as well.  I’m sure you morning classes will agree I’m more active in the afternoon.  Not really a morning person. J

Snake eel

Snake eel

Everyone is so great to me here.  They were very considerate during my seasick time.  I actually have been sitting up on the bridge with Captain Jimmy.  I can see the horizon and feel more stable.  Otherwise we are below decks looking at computer screens for the HabCam or working on the back deck looking at the dredged creatures.

Today we are doing some back tracking to get a start on more dredging and that has allowed me to get this blog in.  I really wanted it to be sooner, but that’s the story.

 

 

 

 

 

 

Channa Comer: Crabs and Stars, May 15, 2011

NOAA Teacher at Sea
Channa Comer

On Board Research Vessel Hugh R. Sharp
May 11 — 22, 2011

Mission: Sea Scallop Survey Leg 1
Geographical area of cruise: North Atlantic
Date: Monday, May 15, 2011

Weather Data from the Bridge
Air Temperature: 16.2C, Mostly Cloudy
Wind Speed: 11.6 knots
Water Temperature: 13.4C
Swell Height: 1.0 meters

Science and Technology Log
Question of the Day (See the answer at the end of the post)
How do you count a basket of crabs?

It’s hard to believe that we’re already at the halfway mark of the cruise. Since my last log, we’ve covered a total of 966 nautical miles. Today, we’ve traveled from Hudson Canyon which is 60 nautical miles east of Atlantic City to about 50 nautical miles from the coast of Point Pleasant, NJ.

Bucket of Crabs

Bucket of Crabs

Each day, the boat stops at predetermined points along the route. At each stop, the scallop dredge is lowered to the ocean floor at depths ranging from 15 to 60 fathoms. The dredge is then towed for 15 minutes at a speed of 3.8 knots. When 15 minutes has passed, the dredge is brought up and the catch is dumped onto a platform were we all wait anxiously to see what comes up. Once the empty dredge is secure, we get to work sorting the catch. Scallops and fish get separated, with everything else collected into baskets, cataloged as “trash” and returned to the ocean. The scallops are measured, and the fish are sorted by species, then counted, weighed and in some cases saved for further scientific study back at NOAA labs. Once everything has been counted, weighed and measured, it’s time for my favorite activity – shucking! Scallops are shucked and if there’s time, washed bagged and placed in the deep freezer for Paul to use in the galley for meals. To date, we’ve completed 90 tows and dredged 23,212 scallops.

What comes up at each catch depends on the location of the tow. The southernmost, areas that have been open, or those areas that have recently been closed will usually yield fewer scallops. Scallop yields increase as we head northward and in areas that are closed to fishing. In addition to scallops, our tows have included a variety of deep sea fish, starfish, lots of live sand dollars (with their accompanying green slime), and very often, mud.

At select tows, representative samples of scallops are processed beyond the usual length measurements. The shells are scrubbed clean and weights are recorded for the meat and gonad (reproductive organ). The shells are then labeled and bagged for transport to the lab where they will be aged. The age of scallops are determined by counting the number of growth rings on the shell – similar to counting rings on a tree.

Every three tows is my favorite – Crabs and Stars!! In this tow, in addition to the usual sorting and measuring, all Cancer crabs are collected, counted and weighed and a representative sample of starfish are sorted by species, then counted and weighed. Astropecten, a small starfish is a predator of scallops and the most abundant species of starfish that we’ve counted. Usually, a tow that has large numbers of Astropecten has very few scallops. Being a stickler for detail, having the job of counting starfish has been perfect for me.

Did you know?
Starfish eat a scallop by attaching themselves to the scallop in numbers, forcing the shell open, then extruding their stomachs into the shell and digesting the meat.

Animals Seen
Dolphins
Red Hake
Sea Mouse
Chain Dogfish
Little Skate
Four Spot Flounder
Red Sea Robin
Sea Urchin
Snake Eel
Ocean Pout
Sand Dollar
Sand Lance
Goosefish
Starfish
Gulf Stream Flounder
Black Sea Bass
Hermit Crab
Sea Raven

Personal Log
Day 3 – Thursday, May 12, 2011
With my sea sickness over after the first day and having adjusted to my new sleep schedule — I actually get to sleep a full 8 hours! — the days are starting to take on a nice flow. It’s been great being part of a team. We’re like a well-oiled machine. Everyone in my crew continues to be generous, sharing the best shucking techniques and giving me a little extra time to take photos and collect samples. We’ve jokingly renamed the “crabs and stars” tow to “crabs, stars and mud”. It’s really hard to count starfish when they’re covered in mud. Dinner was especially delicious today with salmon in pesto sauce with potatoes and broccoli.

Day 4 – Friday, May 13, 2011
The day started out cloudy and overcast, but the sun made an appearance late in the afternoon. The first tow of the day was my favorite — Crabs and Stars!! — with accompanying mud. As part of the Teacher at Sea program, in addition to my logs, I am required to write a lesson plan. I’ve started to draft what I think will be a great unit using the sea scallop as a springboard to explore issues in ecology and the nature of ecological science. Highlights will be an Iron Chef style cooking competition using scallops and a design challenge where students will have to build a working model of a scallop dredge. Vic has been great with providing whatever data, materials and background information that I need for my lessons. Lunch today was chicken burritos with fresh, spicy guacamole.

Day 6 – Sunday, May 15, 2011
Since its Sunday, I decided to take it easy and instead of trying to get a lot done before my shift and during the breaks, I took it easy and watched a little TV. With satellite TV and a large selection of DVDs, there are always lots of options. Although the guys tend to prefer sports or reality TV. The first few tows were back to back which meant little time for breaks, or snacks, or naps. Just enough time to clean up, shuck and be ready for the next tow.

Day 7 – Monday, May 16, 2011
The trip is half over. It’s hard to believe. The tows were once again, back to back with a fair amount of scallops, but I think after today, we won’t need to shuck anymore. Yay! Today was the day that the animals fought back. I was chomped by a scallop and a crab! The scallop was more of a surprise than a pain, but the crab clawed right through my glove. After days with no restrictions, we received the warning from the engineers today that we have to be careful with the faucets. Dripping faucets waste water and it takes time for the water to be converted through condensation in the condenser to usable water. If we’re not more careful, we’ll be faced with restrictions on how much water we can use……… I hope that doesn’t happen since I think we all officially smell like fish. Lunch today was cream of asparagus soup, yummy and reminiscent of my recent trip to Peru. The only thing missing was Quiona. And finally, today was the day that I’ve been waiting for. I found my favorite ice cream. I’ve been rationing myself to one per day, but after I found my favorite – butter pecan ice cream sandwiches – I could not resist a second.

Answer to Question of the Day: Very carefully!