Fish Habitat: Essential Fish Habitat and Rehabilitation

Abstract

<em>Abstract.—</em> Freshwater and marine essential fish habitat (EFH) for chinook <em>Oncorhynchus tshawytscha</em> , coho <em>O. kisutch</em> , pink <em>O. gorbuscha</em> , and sockeye <em>O. nerka </em> salmon within Washington, Oregon, California, and Idaho was described and identified using the available literature and databases on salmon distribution and life history. The diversity of freshwater habitats utilized by individual species of salmon coupled with the limitations of existing distribution maps precluded identification of specific stream reaches, wetlands, and other water bodies as EFH for Pacific salmon. A more holistic watershed approach consistent with the ecosystem method recommended by the revised Magnuson-Stevens Fishery Conservation and Management Act was necessary. Therefore, Pacific salmon freshwater EFH was delineated and described as all existing water bodies currently and historically utilized by Pacific salmon within selected watersheds defined by U.S. Geological Survey hydrologic units. Areas above some long-standing artificial barriers to juvenile and adult salmon migration were excluded from designation as Pacific salmon EFH. Delineation of marine EFH was also problematic because of the paucity of scientific studies on offshore Pacific salmon habitat use and distribution. However, available scientific data augmented by information from commercial fisheries indicate that juvenile salmon are found in high concentrations in the nearshore areas of the continental shelf off the Washington, Oregon, and California coasts from late spring through fall. Therefore, Pacific salmon marine EFH was identified as all waters within 60 km of the Washington, Oregon, and California coasts north of Point Conception, California. This initial effort to identify Pacific salmon EFH emphasized the need for accurate, fine-scale geographic information systems data on freshwater and marine salmon distribution and habitat quality and the need for compilation of uniform data sets. Future efforts should focus on developing accurate seasonal salmon distribution data at a 1:24,000 scale to aid in more precise and accurate delineation of Pacific salmon EFH. Furthermore, detailed information on winter distribution of Pacific salmon would be useful in delineating marine EFH.