Effects of the Nestucca oil spill on seabirds along the coast of Vancouver Island in 1989

On 23 December 1988, the barge Nestucca was damaged off Gray's Harbour, Washington, spilling 875,000 liters of bunker C oil, resulting in high mortality of seabirds. The impact of the spill on seabirds is documented based on data collected from British Columbia. The spill resulted in 3,568 dead oiled seabirds coming ashore on Vancouver Island. Identified birds included 31 species, dominated by Common Murres (42%), Cassin's Auklets (32%), other alcids (9%), scooters (6%) and gulls (4%). Most victims were offshore species, well decomposed and encapsulated in thick oily mousse. Most lightly-oiled carcasses probably sank. Flotation tests showed that 21% of heavily oiled alcid carcasses sank 21-25 days after the spill, 44% after 25-35 days, and 63% after 50-60 days. Scavangers had eaten 54% of all carcasses, and some oiling of scavenging gulls and eagles was reported. Overall mortality in Washington and British Columbia was estimated to be 56,250 birds (probable range 47,500-68,500 birds). 55 refs., 7 figs., 20 tabs