How many seabirds were killed by the Exxon Valdez Oil Spill?

By:  and 
Edited by: S.D. RiceR.B. SpiesD.A. Wolfe, and B.A. Wright

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Abstract

After the Exxon Valdez oil spill of 24 March 1989, 36,115 dead seabirds were recovered from beaches and processed at morgues. Most or all of 1,888 live oiled seabirds brought to rehabilitation centers also died and about 3,260 oiled carcasses were never delivered to morgues. Of these 41,263 carcasses accounted for, we estimated conservatively that only 30,000 were killed by oil pollution. Carcass drift and recovery experiments conducted in the affected area during the spill and 1 year later, along with historical experiments conducted in other oceanographic regions, suggest that only a fraction (range = 4-30%) of birds killed were likely to have been recovered from beaches. Regression analysis of these drift-recovery data predicts a 15% recovery rate (r' = 0.38, P = 0.015). We recognize uncertainties in the assumptions and parameter values used to extrapolate total mortality from drift-recovery data, but we have confidence that mortality fell within the extreme range of estimates (100,000-690,000 birds killed) because these reflect a very wide range of observed and experimentally determined parameter values. Total mortality can also be estimated by comparing pre- and postspill colony population estimates. Uncertainties about these census data are greater than those associated with drift-recovery data, but nonetheless provide an independent mortality estimate of similar magnitude. Taken together, all evidence suggests that about 250,000 seabirds were killed by Exxon Valdez oil.

Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title How many seabirds were killed by the Exxon Valdez Oil Spill?
Year Published 1996
Language English
Publisher American Fisheries Society
Contributing office(s) Alaska Science Center
Description 8 p.
Larger Work Type Book
Larger Work Subtype Conference publication
Larger Work Title American Fisheries Society Symposium 18: Proceedings of the "Exxon Valdez Oil Spill Symposium"
First page 712
Last page 719
Conference Title American Fisheries Society Symposium 18: Exxon Valdez Oil Spill Symposium
Conference Location Anchorage, AK
Conference Date February 2-5, 1993
Country United States
State Alaska