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Overview of State-Managed Marine Fisheries in Southwestern Alaska with reference to the southwest stock of sea otters. Regional Information Report 5J03-02, Alaska Department of Fish and Game, Juneau, Alaska.
EXECUTIVE SUMMARY The Southwest stock of sea otters Enhydra lutris has been declining over the last two decades. The U.S. Fish and Wildlife Service (FWS) is currently reviewing the status of sea otters and contemplating listing the species under the Endangered Species Act. This purpose of this report is to provide background information to the FWS about the potential for interactions of commercial fisheries and sea otters, both during the period of sea otter decline and for future projections. This report addresses potential interactions in commercial fisheries managed by the State of Alaska, including those for which federal agencies delegate management authority to the State. Potential interactions between fisheries and sea otters include direct entanglement in fishing gear leading to direct mortality and/or serious injury, and competition for prey species. Fisheries with potential for entanglement are considered separately from fisheries with potential for competition in this report. With a few exceptions, fisheries that have potential for competition with sea otters do not use gear that has potential for entanglement. The National Marine Fisheries Service has determined that the set gillnet fishery for salmon, trawl fisheries for groundfish, and pot fisheries for Pacific cod Gadus macrocephalus, king crab Paralithodes camtshaticus, and Tanner crab Chionecetes bairdi have the potential to entangle sea otters. To evaluate the potential for entanglement in state-managed fisheries, an analysis of trends in fishing effort in state-managed fisheries that use set gillnets, trawls, and pots, and occur in the range of the Southwest stock of sea otters, was conducted over the period 1970 to present. The FWS has determined that sea otters feed primarily on benthic invertebrates in shallow water (<100 m). Fisheries for benthic invertebrates in the range of the Southwest stock of sea otters include those for Dungeness crab, shrimps, razor and other clams, sea urchins, sea cucumbers, sea urchins, scallops, and octopus. To evaluate the potential for competitive interactions of fisheries and sea otters, narrative descriptions of the fisheries for these benthic invertebrates which occur within the range of the Southwest stock of sea otters are included in this report, along with summaries of catch and effort data. The range of the Southwest stock of sea otters is defined by FWS as including the coastal areas of the Aleutian Islands, the north side of the Alaska Peninsula from False Pass to the Kvichak River, the south side of the Alaska Peninsula from False Pass to Cape Douglas, the Kodiak Archipelago, the Barren Islands and Kamishak Bay in Cook Inlet, and the Pribilof Islands. The State of Alaska generally manages those waters which occur within 3 miles of shore. In some instances, usually where there was a management history that predated the Fishery Conservation and Management Act of 1976, the federal government has delegated management authority to the State. For some other “parallel” fisheries, management regulations are coordinated between state and federal waters so that the same seasons, gear restrictions, quotas nd other regulations apply. There are very few recorded instances of sea otter take in Alaskan fisheries, and entanglement risk is thought to be very low. Some gears, such as salmon gillnets, theoretically have the potential to entangle sea otters, but are usually fished outside of sea otter habitat or in other ways such that the reported instances of sea otter entanglement is very low. No fishery records or observations suggest that fishing gear encounters contributed to the decline of sea otters. Most commercial fisheries in the area of the Southwest stock of sea otters that take benthic invertebrates occur offshore, well outside the foraging range of sea otters. Exceptions to this include fisheries for Dungeness crabs, sea cucumbers, and sea urchins. There is a long history of competitive interactions between Dungeness crab fishermen and sea otters in other locations. Sea otters are usually able to forage far more efficiently and persist at lower crab densities than is feasible for commercial fishermen or allowed under fishing regulations. Alaskan crab fisheries are restricted by seasons, sex, and size limits, leaving the females and undersized males unharvested. A very small fishery for green sea urchins exists along the west side of Kodiak Island, with a few landings recorded from Unalaska Island as well. While there is potential for overlap with sea otter diets, fishery quotas are thought to be low enough so as to not cause local depletion, and removals have occurred only in limited areas. Red sea cucumber fisheries occur around Kodiak Island, and to a lesser extent in several areas off of the Alaska Peninsula. The fisheries are regulated by area-specific guideline harvest levels which are thought to be conservative and not result in localized depletion. Sea cucumber fishers are present in the nearshore areas for a very limited number of days each year, so disturbance is not thought to be a problem. In addition, a significant proportion of the sea cucumber resource occurs below practical diving limits and is not harvested, although it is well withing sea otter diving ranges. In many instances, state fishing regulations are in addition to, and more conservative than, associated federal fishing regulations. For instance, most state waters in the central and western Gulf of Alaska are closed permanently to trawling. The state waters Pacific cod fishery is restricted to fixed gear only. In addition, restrictions are placed on numbers of pots or jigs in an effort to provide for slow-paced fisheries that minimize effects on habitat and other species. State regulations prohibit directed fisheries for sharks and, with a few minor exceptions, no fisheries are permitted for forage fishes owing to their ecological role in the marine environment. Very strong resource conservation principles are embedded in a number of policies that guide the Alaska Board of Fisheries in their development of state fishing regulations, including the Sustainable Salmon Fishery Policy, Policy on King and Tanner Crab Resource Management, and the Guiding Principles for Groundfish Fishery Management.