Exxon Valdez Oil Spill Trustee Council Restoration Exxon Valdez Oil Spill Trustee Council Marbled Murrelet Brachyramphus Marmoratus Marmoratus

M arbled murrelets, Brachyramphus marmoratus marmoratus, are small seabirds of the Alcid Family. Alcids are diving seabirds inhabiting the north Pacific and include murres, puffins, auklets, murrelets, and guillemots. Marbled murrelets occur in nearshore marine environments from California to Alaska, nesting primarily in old-growth forests. A larger subspecies, B. m. perdix, is found along the Kamchatka Peninsula and the Sea of Okhotsk in the western Pacific. Recent genetic studies indicate that the Asian form may be a distinct species. 1 A drastic decline in population is cause for concern through­ out its range. It is formally listed as a threatened species in California, Oregon, Washington and British Columbia. The main threat to marbled murrelets has been loss of their old-growth forest nesting habitat. Other threats come from gillnet bycatch mortality, oil spills, disturbance in nearshore feeding areas, and long-term changes in oceanic conditions affecting their prey. 2 The 1989 Exxon Valdez oil spill had a greater impact on marbled murrelets than any previous oil spill in North America, and most likely, in the world. 3 Most of the world's population of marbled murrelets breed in Alaska and some of the highest densities of murrelets occur in the area hit by the Exxon Valdez oil spill. Thus, a large percentage of the world's population was at risk from the spill. In summer, the marbled murrelet is common throughout the spill zone, including Prince William Sound, where it is the most abundant seabird. 4 U.S. Fish and Wildlife surveys in south­ eastern Alaska, Prince William Sound, and lower Cook Inlet estimated 550,000, 100,000 and 60,000 in those regions, respectively. 5 The marbled murrelet began its decline in Prince William Sound before the oil spill. Post-spill estimates suggest a 67% decline since surveys done in 1972 and 1973,