This past weekend marked a new venture into shark-related field work. For the better part of two months I’ve been fighting the good fight to keep ECU’s acoustic array up off of Cape Hatteras, and last Friday and Saturday finally managed to actually play with some sharks. The goal, as with the Summer of the Shark field days, is to catch, ID, and measure as many juvenile sharks as possible, with the added responsibility of surgically implanting acoustic transmitters into individuals of key species. This turned out to be the best couple field days I’ve had in my scientific career so far, and was a definite change from not catching a single damn shark over the summer. The weekend’s tagging trip was also a shining example of why it pays to not alienate fishermen.
This round of field work is part of an NC Sea Grant Fisheries Resource Grant (FRG) project, which means we work with commercial fishermen to answer questions relevant to fisheries science. This is a great program that goes a long way towards bridging the divide between commercial fishermen and researchers: it allows fishermen to participate directly in the science and scientists to make use of the fishers’ knowledge of local waters.
In this case we were working with frequent Rulifson lab collaborator Chris, a commercial gillnetter out of Hatteras. Chris normally fishes for monkfish and dogfish,but this time took us to a few spots in the Hatteras Bight that local fishermen have been trying to avoid due to the high number of “biters” in the area. Hatteras fishermen classify sharks as either “dogs,” smooth and spiny dogfish, or “biters,” which are usually small or juvenile Carcharhinid sharks. The local names get more detailed than this, with species-specific names such as “white-dotters” for Atlantic sharpnose sharks (because the adults have white spots) and “circle biters” for small sandbar sharks (because they can tear circle-shaped holes in your rain gear if you make the mistake of only holding them by the tail). Chris has been fishing for decades and knows a ton about the things that swim by the Cape at any given time of year.
Chris really put us on the sharks. In two days of sampling, we caught and measured 180 juvenile sandbar sharks, 4 sharpnose sharks, two dusky sharks, one smooth dogfish, and one 6-foot scalloped hammerhead. Three angel sharks, some false albacore, and two of the largest shad I’ve ever seen also made appearances. Of those sharks, 15 sandbars and one dusky are now carrying acoustic tags and will hopefully show up on our array and others deployed along the Atlantic coast, providing crucial data on their migration routes.
That’s the science. Here are the pictures.
All in all, a pretty successful trip. I’m looking forward to seeing where our tagged sharks go, and hope to add more sharks to the roster soon.