NOAA Teacher at Sea: Anne Byford
Aboard: R/V Hugh R. Sharp
Mission: Sea Scallop Surveys
Location: Off the Coast of New England
Date: June 11, 2010
Weather Data at 1:35pm EDT:
Location at 1:35pm EDT: Lat: 40 30.07 N Long: 69 08.66 W
Water Depth: 77.5 m
4th Day at Sea
Why Count Sea Scallops?
That had to be the most common question I got asked before coming on this trip. Much of the information below is from the NOAA FishWatch website (www.nmfs.noaa.gov/fishwatch/species/atl_sea_scallop.htm).
Economically, sea scallops are an important species; in 2008 the scallop harvest was about 53.5 million pounds and was worth about $370 million. The population is not currently considered to be overfished and has been above minimum sustainable levels since 2001. Formal management began in 1982 with the Atlantic Sea Scallop Fisheries Management Plan. The management plan includes limiting new permits, restrictions on gear and on the number of crew on a boat. Since about 2000, the biomass of scallops has been increasing. Biomass is estimated by using the weight of scallops per tow on cruises like this one. Combinations of biomass estimates and estimates of the commercial catch are used to update and adjust the management plan.
Sea Scallops (Placopecten magellanicus) are filter feeders. They can live up to 20 years and begin reproducing at about 2 years, with maximum fertility reached at 4 years. A single female scallop can produce up to 270 million eggs in her life. This high reproductive capacity has helped the scallop population recover relatively quickly. Gender can be determined by the color of the gonad; females are orange while the male gonad is white. Adult scallops average between 6 and 7 inches from hinge to tip (called height) but can be as big as 9 inches. Age can be estimated by counting the rings on the shell. Scallops can “swim” by opening and closing the two shells. This is a useful adaptation for escaping from predators, including flounder, cod, lobsters, crabs, and sea stars. Scallops are harvested for the adductor muscle (the one that opens and closes the shell). There is no commercial aquaculture of scallops in the US as of August 2009.
A storm moved through beginning on Wed. evening (day 2) and stayed with us most of Thursday. By the end of shift on Wednesday, we were working on deck in full foul weather gear and life jackets. Thursday we had an 8 hour steam between dredge sites and by the end of shift on Thursday, the seas had begun to smooth out. Friday was quite nice, weather-wise.
I am learning to shuck scallops, though I am about half the speed of many on the boat. I am also learning to tell the various types of flounder and other fish apart as well. It’s not always obvious which type of flounder or hake is which.
Goose fish (aka monk fish), several more varieties of flounder, sea urchins, sea cucumbers, eel pout, some very large skates, 3 types of sea stars and 1 type of brittle star.