Conservation and Management Implications of Deep-sea Coral and Fishing Effort Distributions in the Northeast Pacific Ocean
Authors: Lance E. Morgan, Marine Conservation Biology Institute; Peter Etnoyer, Aquanautix Consulting; Astrid J. Scholz & Mike Mertens, Ecotrust; Mark Powell, The Ocean Conservancy
The conservation of deep-sea corals is of growing interest in the United States. A range of issues including biodiversity protection, conservation of seafloor habitats, and the role of deep-sea corals as essential fish habitat places greater significance on understanding the distributions of these corals and fishing activities. At the same time overfishing of some groundfish populations highlights the need for ecosystem-based management. Here we present records of habitat-forming deep-sea corals from the United States Pacific Fishery Management Council region that we analyze in relation to differential ecological impacts of demersal fishing gears. We use an ecological footprint approach combining groundfish catch by gear type with a previously published ecological severity ranking of fishing gears.
Deep-sea corals in the Isididae, Paragorgiidae, Primnoidae, Antipathidae and Stylasteriidae families are widespread throughout their depth ranges in the Northeast Pacific, although the scleractinian families Oculinidae and Caryophylliidae are relatively rare. In this qualitative analysis, we highlight areas of relatively high coral concentration such as the West Coast continental shelf break and Monterey submarine canyon, areas that are presently relatively lightly fished but where corals are recorded. Bottom trawling gear has far and away the region's largest ecological footprint. Other gears with smaller footprints include bottom longline, pot/trap and hook and line gear. Most of these impacts seem to have occurred in areas where deep-sea corals are relatively scarce, but fishing closures to protect rockfish implemented in 2002 may have the unfortunate effect of redistributing fishing effort to areas of deep-sea coral aggregations. An ecosystem-based management approach would detect and prevent such unintended consequences of redistributing fishing effort and placing deep-sea corals in harm's way.
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