{"id":21943,"date":"2018-05-10T12:52:42","date_gmt":"2018-05-10T16:52:42","guid":{"rendered":"https:\/\/ncseagrant.ncsu.edu\/currents\/?p=10330"},"modified":"2024-05-21T15:54:09","modified_gmt":"2024-05-21T19:54:09","slug":"the-future-of-shrimping-whats-new-in-conservation-gear","status":"publish","type":"post","link":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/the-future-of-shrimping-whats-new-in-conservation-gear\/","title":{"rendered":"The Future of Shrimping: What\u2019s New in Conservation Gear"},"content":{"rendered":"
Sara Mirabilio<\/a> is a fisheries specialist for North Carolina Sea Grant.<\/em><\/p>\n Next week, the N.C. Marine Fisheries Commission, or MFC, will discuss the results of a three-year, collaborative research effort to develop technical solutions to reduce bycatch in North Carolina\u2019s shrimp trawl fishery.<\/p>\n Generally speaking, bycatch refers to the unwanted fish and other marine creatures caught by fishermen while going after their target catch. Most of this bycatch is discarded overboard \u2014 either because regulations don\u2019t allow fishermen to keep the species, or because those species are undesirable to seafood consumers. Fishermen can retain a small portion of bycatch to sell if it\u2019s legal and marketable.<\/p>\n A year ago, I wrote a blog post<\/a> to explain the research process and the results from the first two years. In late 2014, the N.C. Division of Marine Fisheries, or DMF, had formed an industry work group to guide testing of experimental bycatch-reducing gear for shrimp trawls in North Carolina waters out to three miles in the ocean. As North Carolina Sea Grant fisheries specialists, Scott Baker and I are members of the work group.<\/p>\n The specific goal has been to achieve an additional 40-percent reduction in bycatch coming aboard trawlers. Currently, federally mandated bycatch reduction devices, or BRDs, reduce this unwanted catch by 30 percent, compared with nets that don\u2019t have BRDs. In other words, the new benchmark in North Carolina would reduce bycatch by at least 58 percent in relation to nets without a BRD.<\/p>\n In the first two years, four out of nine experimental gear configurations met or exceeded the target of 40 percent additional bycatch reduction.<\/p>\n We can\u2019t attribute observed reductions to one particular experimental gear element, but we can share some observations. For example, we combined two federal fisheyes, which are essentially cone-shaped, rigid metal frames that form an opening for fish to escape through. Together, these federal fisheyes provided an opening almost four times that of the industry-standard state fisheye.<\/p>\n Our hunch is this additional space allows larger fish to escape the trawl. The larger escape openings also likely result in a larger area of disturbed water flow, which has been shown to increase escapement rates for all sizes of fish.<\/p>\n We tested the larger fisheye in conjunction with a modified turtle excluder device, or TED. This device, which looks a bit like a grill grate, blocks turtles from passing through a net. A large opening in the trawl near the TED, typically covered by a moveable flap, allows any captured turtles to escape.<\/p>\n Reducing the bar spacing in the TED also appears to contribute to overall bycatch reduction. That reduction was even more pronounced after we increased the mesh size of the tailbag \u2014 the end-most part of the trawl where shrimp and fish are collected.<\/p>\n During the first two years of our research, only larger shrimp boats \u2014 that is, greater than 40 feet \u2014 tested experimental gears, and principally in estuarine waters. For the third and final year of the study, smaller boats, as well as ocean-going trawlers, tested additional gear configurations.<\/p>\n Based on the most recent five-year average, in North Carolina smaller vessels comprise nearly 73 percent of the state\u2019s shrimp trawl fleet. Further, they account for 56 percent of the effort, as identified by the number of trips reported to the N.C. Trip Ticket Program, administered by DMF. Also, while the majority of shrimp trawling effort occurs in estuarine waters, approximately 25 percent occurs in the nearshore Atlantic Ocean.<\/p>\n