Effects of Commer Effects of Commercial Otter Cial Otter Cial
American Fisheries Society Symposium 41:439–460, 2005 © 2005 by the American Fisheries Society Effects of Commercial Otter Trawling on Benthic Communities in the Southeastern Bering Sea ELOISE J. BROWN,1 BRUCE FINNEY, AND SUE HILLS Institute of Marine Science, University of Alaska Fairbanks, 245 O’Neill Building, Post Office Box 757220, Fairbanks, Alaska 99775, USA MICHAELA DOMMISSE Monash University, Department of Geography and Environmental Science, Post Office Box 11A, Clayton 3168, Australia Abstract. The effects of commercial bottom trawling for yellowfin sole Limanda aspera on benthic communities were investigated in a sandy habitat exposed to high wave and tidal disturbance at 20–30 m depth in the southeastern Bering Sea. We compared an area that has been closed to commercial trawling for 10 years with an adjacent area that is now open to commercial trawling. In addition, we examined the immediate effects of experimental trawling on benthic community structure in the area closed to trawling. The fished area was characterized by reduced macrofauna density, biomass, and richness relative to the closed (unfished) area, but diversity was not different. Interannual variability of macrofauna assemblages was high in the system, yet assemblages in the two areas were distinguished using multivariate analyses and dominant taxa. After 10 years, sessile taxa (e.g., Maldanidae polychaetes) were prevalent in the closed area, and mobile scavengers (e.g., Lysianassidae amphipods) were more common in the fished area. Immediate responses of macrofauna to experimental trawling were subtle (i.e., reduced richness, absence of rare taxa, and patchy changes in assemblage biomass), but no differences were detected relative to controls for density, diversity, or total biomass.
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