Full report - Conservation Gateway

Chapter 7 - Demersal FishInvasive speciesIntroduction and transportation of non-native invasivespecies is another human impact of growing concern.Invasive species have altered benthic habitats and foodweb dynamics at a number of locations within the region.Two species of particular recent concern are Codium andDidemnum. Codium is an invasive green alga (commonlyknown as dead man’s fingers) that has taken hold in manynearshore coastal waters within the region from the Gulfof St. Lawrence to North Carolina. Codium is a dominantspecies in some subtidal zones and can radically altersubtidal community composition, structure, and function(Levin et al. 2002). The rapid growth of this species andits ability to regenerate from broken fragments assist in itsability to outcompete native plant species like kelp beds,the primary shelter for many finfish and invertebrates.Didemnum is an invasive tunicate that smothers benthicorganisms; it has been found in many parts of the region,causing particular concern by its recent spread across asignificant portion of prime fishing grounds on GeorgesBank. While extensive studies on the effect of Didemnuminvasion of seafloor habitats have not been completed todate, evidence suggests it can overgrow scallops, mussels,other sessile species, and gravel potentially creatinga barrier between demersal fish and prey items includingworms and bivalves (Bullard et al. 2007). In addition,mat surfaces may reduce the area of the seabed suitable forsettlement of larvae of other benthic species, including seascallops (Valentine 2007).Management andConservationRegulatory AuthoritiesMost of the species included in the demersal fish groupare formally managed by one of three fishery managemententities: the NEFMC, the Mid-AtlanticFisheries Management Council (MAFMC), or theASMFC. Regulatory authority for the NEFMC and theMAFMC is provided by the Magnuson Stevens FisheryConservation and Management Act as amended in2006. The Magnuson Stevens Act delegates responsibilityfor developing fishery management plans (FMP) tothe regional councils, but those plans must be approvedby the NMFS. Prior to approval and promulgation ofimplementing regulations, NMFS must review the planssubmitted by the regional council and ensure they complywith ten National Standards included in the MagnusonStevens Act. These standards require that regulationsachieve optimum yield while preventing overfishing, rebuildoverfished populations, minimize adverse impacts toessential fish habitat caused by fishing activities, minimizebycatch and discard of non-target species, and minimizeadverse socio-economic impacts on fishing dependentcommunities consistent with the other requirements mentionedabove.Regulatory authority for the ASMFC is provided by theAtlantic Coast Fisheries Cooperative Management Actas amended in 1993. First created in 1943, the ASMFCincludes representatives from the 15 coastal states on theAtlantic seaboard. Each state appoints three commissioners,representing state fisheries management agencies,state legislators and a member of the public. The ASMFCis responsible for developing management plans for fisheriesoccurring primarily in state waters (from 0-3 miles offshore).The ASMFC focuses on five major areas interest:1) Interstate Fishery Management Plans, 2) Research andStatistics, 3) Fisheries Science, 4) Habitat Conservation,and 5) Law Enforcement.Current Conservation EffortsEleven of the species included in the demersal fish groupare managed by the NEFMC under the NortheastMultispecies Fisheries Management Plan (Acadian redfish,American plaice, Atlantic cod, Atlantic halibut, haddock,ocean pout, pollock, white hake, winter flounder,witch flounder, and yellowtail flounder). In 2004, theNEFMC and NMFS implemented a formal rebuildingprogram for many of these species through Amendment13 to the Multispecies FMP. The rebuilding plan includesimplementation of target fishing mortality rates, biomasstargets, measures to minimize fishing-related impacts toEssential Fish Habitat, and rebuilding schedules. Mostspecies are scheduled to be rebuilt by 2014, though some7-72Northwest Atlantic Marine Ecoregional Assessment • Phase 1 Report