Assessing Biodiversity: Pacific Northwest Coast Ecoregion
Conservation assessments serve as a guide for planners and decision-makers, and have no regulatory authority. These assessments are conducted in a transparent manner and are made accessible to the widest range of users possible. They should be treated as a first approximation, and the gaps and limitations described within these regional assessments must be taken into consideration.
The Pacific Northwest Coast ecoregional assessment is the product of a partnership initiated in 2001 to identify priority conservation areas in this ecoregion. The Nature Conservancy, the Nature Conservancy of Canada, and the Washington Department of Fish and Wildlife are the primary partners in this project. NatureServe, the Oregon Natural Heritage Information Center, the Washington Natural Heritage Program, Nearshore Habitat Program of the Washington Department of Natural Resources, and the British Columbia Conservation Data Centre were major contributors of technical expertise and data. The project has also benefited from the participation of many other scientists and conservation experts as team members and expert reviewers. The first iteration of the ecoregional assessment is now complete which identifies conservation priority areas in terrestrial, freshwater, and coastal marine environments.
This ecoregion is a narrow, elongated landscape lying to the west of the Coast Range mountains and stretching from the southern border of Oregon to the northern tip of Vancouver Island. The ecoregion includes nearly all of the Olympic Peninsula and most of Vancouver Island, British Columbia encompassing some 8,170,260 hectares (30,900 square miles) of temperate rainforests, beaches and rocky intertidal zones, bays and estuaries and coastal rivers.
The outer coasts of Oregon, Washington and the West Coast of Vancouver Island in British Columbia offer a wide range of intertidal and subtidal marine diversity. From exposed rocky shores of the Pacific Ocean to protected estuarine systems, the Pacific Northwest Coast ecoregion encompasses over 9,000 kilometers of shoreline. In general, the region is characterized by large amounts of rain in places along the coast which contribute freshwater run-off and land-derived nutrients to the marine environment.
We have added an offshore marine boundary to the Pacific Northwest Coast ecoregional assessment that originally delineated only terrestrial and coastal environments. This marine region boundary generally follows those identified by the NOAA NERRS program. These are biogeographically-based, determined primarily by the distribution of marine species and ecosystems. The Pacific Northwest Coast ecoregional assessment includes the continental shelf and slope down to 2,500 meters below sea level.
For this case study only the U.S. portion of the marine ecoregion was examined. We developed a 500 hectare planning unit with a hexagon spatial format for compiling information on biological and physical features and threats. Where units straddled the coastline we split those hexagons to account for the boundary between land and sea. The planning region contained 32,180 units for a total of 14,263,550 hectares. Split between land and sea units, there were 13,188 (5,467,050 hectares) and 18,991 (8,796,500 hectares) units respectively. Although our analysis was integrated we focused on site selection output from the marine portion of the study area.