catcher processors, and in 1999, the catch is almost evenly divided between the two sectors (National Marine Fisheries Service, 2001c). There are 202 catcher vessels, most 18–37 m long (Hiatt and Terry, 1999). These vessels must carry the National Marine Fisheries Service observers 30 percent of the time. There are 40 catcher–processors ranging from 41 m to 130 m—most are longer than 54 m—that have 100 percent observer coverage (Hiatt and Terry, 1999). There are three “mother ships” that are longer than 133 m. Ownership of the groundfishing fleet is mixed; some vessels are owned by individuals, some by limited partnerships, and others by processing companies.
The state of Alaska manages the weathervane scallop fishery under the auspices of a federal fishery management plan that implements a license limitation program. The fishery is prosecuted by catcher– processor vessels that, with the exception of a few small vessels in Cook Inlet, are required to carry observers. The state of Alaska also manages shrimp fisheries throughout state and federal waters. Catches are taken mostly by otter trawl, beam trawl, and pot gear. The open-access shrimp fisheries currently have few participants because of low shrimp abundance, except in Southeast Alaska where more stable fisheries under a state-run limited entry program have sustained higher participation.
The analysis of the intensity and distribution of fishing effort in the North Pacific was divided into three areas: the Bering Sea, the Gulf of Alaska, and the Aleutian Islands. The effort data include only trawl tows sampled by observers. Observer coverage includes 100 percent of the vessels longer than 38 m, and 30 percent of the 22–41 m vessels. Data were unavailable for vessels less than 22 m. Although the database is not complete, it is roughly representative of the spatial distribution and temporal changes in intensity.
Bottom trawling in the Bering Sea during the early 1990s was most intense on the slope and shelf area north of the Aleutian Islands and the Alaska peninsula in the vicinity of Unimak Island, east of the Pribilof Islands, west of Bristol Bay, and off Cape Constantine (Appendix B). Large areas of the Bering Sea appear to have no trawling activity because of closed management areas, less productive fishing grounds, or unobserved tows. Both the spatial extent and the intensity of fishing effort decreased significantly in the 1990s. Between 1998 and 2000, 57 percent of the total area monitored was swept annually by bottom trawl gear; less than 2 percent of the area was swept more than once a year. The Gulf of Alaska experienced considerably less trawling activity than did the Bering Sea during the 1990s, and there were significant reductions in the geographic extent and the intensity of trawling in the Gulf of Alaska. The number of observed tows in the region was reduced by about half because of management area closures and because of general reductions in fishing effort associated with fisheries management. Bottom trawling off the Aleutian Islands extends from Unimak Island to 168°E longitude. The intensity of trawling was relatively light compared with the Bering Sea during the 1990s, and there was about a 40 percent reduction in observed effort during that decade.
Domestic trawl and dredge fisheries are conducted along most of the continental shelf and slope adjacent to the United States, although the level of fishing effort, and hence the amount of area affected, varies widely by region and by the spatial distribution of the fishing grounds. Groundfish trawls dominate the Alaska, Pacific coast, and New England fisheries; shrimp trawling is the major fishery in the Gulf of Mexico and in the coastal southeast Atlantic.
Over the past decade, management measures in some regions have closed areas to dragged gear to reduce gear conflicts, bycatch, or fishing mortality. Severe stock declines in some trawl and dredge fisheries have resulted in an overall reduction in bottom fishing effort. Although some areas of New England and the Gulf of Mexico are swept frequently, much of the continental shelf and slope area is trawled infrequently (less than one tow per year) if at all.