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Journals 2003/2004
Steven Krous
Cranston High School West, Cranston, Rhode Island
"Habitat Value of Aquaculture Shellfish Gear"
Narragansett Bay, Rhode Island
Various dates in July and August 2003
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DAY 1: Monday August 4, 2003
I met Stephanie Robbins at URI Graduate School of Oceanography this morning. She is a graduate student assisting Dr. Graham Forrester on a research study to evaluate the impact, if any, of shellfish aquaculture operations in RI on the habitat value of the culture areas. Three fish species in particular will be studied, the cunner or "choggy" as Rhode Islanders call them, the tautog or blackfish, and the black sea bass. The latter two species are of commercial importance in RI as food fishes. All three species appear to be in decline so it is perhaps hoped that the reef-like habitat provided by oyster cage systems will provide shelter and/or increased food supply to young of the year and subadults of these favorite groundfish species. I for one would love to see a return of the tautog stocks to their previous abundance. I spent many hours in my teens and twenties freediving with a spear gun to bring this delicious fish "home for dinner"! My dad and his friends spent many October days with cold fingers, baiting multiple hook rigs with green crabs and covering the deck of the boat with blackfish during their fall run.
I also met Devin, an undergraduate student entering her senior year at URI who is also assisting on the project as an intern. She will be evaluating fish mortalities that might result from the two tagging methods that will be used, and also tag losses that might occur after the fish have been tagged and released. These will be critical pieces of information when it comes time to interpret the census data obtained through the mark/recapture method that will be used to estimate population size and use of the artificial reef habitat created by the aquaculture facilities.
Devin and I went to work in the lab, modifying the four flow-through 50-gallon tank systems that will be used for the tag mortality and retention study. Each tank contains 25 black sea bass that will receive one of two different identification tags, plus a control group that will receive similar handling but will not be tagged. I felt useful here, since I could share my experience in aquaculture systems design and maintenance with Stephanie and Devin. We made modifications to the systems that reduced the noise level of the inflow stream into the tanks, a possible source of stress to the fish. We also modified the cover netting to reduce mortalities for "jumpers" who end up on the lab floor-evidently black sea bass are fond of leaping when agitated.
We then went to the main campus to view a video illustrating the technique used for elastomer tagging of fish, a subcutaneous tag that is injected as a liquid using a syringe that then hardens after injection. Different color sequences and locations are used to identify specific fish. I was unaware of this tagging method and found it very interesting. I soon became aware that I'd be unable to bring this technique into my classes- the kits cost over $1,000!!!!!!!!! Not in our science supply budget. Afterward I had a chance to talk to both Stephanie and Devin about what brought them to URI, what they are doing now and their plans for the immediate future. This discussion brought back many memories, and not-so-enjoyable stress responses as I remembered being in the same place that each of them are now, wondering what to do next, hoping that each choice will be the "right" one, and always out of money! It made me appreciate even more where I am now in my life.
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