The following article, published in 2008, summarizes evidence of ship strikes in large whales found dead in Washington State. Please click on title for PDF of full article:
Douglas, A.B., J. Calambokidis, S. Raverty, S.J. Jeffries, D.M. Lambourn, and S.A. Norman. 2008. Incidence of ship strikes of large whales in Washington state. Journal of the Marine Biological Association of the United Kingdom 88:1121-1132.
Below is the abstract of the publication in the Journal of the Marine Biological Association of the United Kingdom and presentation submitted to the 2007 Biennial Conference on the Biology of Marine Mammals in Cape Town, South Africa:
Ship strikes of large whales off Washington State, USA: an analysis using stranding records from 1980-2006
Douglas, Annie B.(1); Calambokidis, John (1); Raverty, Stephen (2); Jeffries, Steven J.(3); Lambourn, Dyanna M.(3); Norman, Stephanie A.(4)
(1) Cascadia Research Collective 218 ½ W Fourth Ave., Olympia, WA 98506 USA
(2) Animal Health Center, British Columbia Ministry of Agriculture and Food, 1767 Angus Campbell Road, Abbotsford, BC V3G 2M3 Canada
(3) Washington Department of Fish and Wildlife, 7801 Phillips Road SW, Lakewood, WA, 98498, USA
(4) Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, WA 98195 USA
Worldwide, fin whales have been recognized as the species most frequently affected by ship strikes, but as more research is undertaken, regional differences in species affected are becoming apparent. In the interest of evaluating ship-strikes off Washington State, an area where several species seasonally travel and feed within major shipping channels, we examined large whale stranding records from 1980-2006. Of 130 whale strandings, 19 (15%), representing seven species, had evidence of ship strikes. There was a significant increase in the number of ship-struck whales over this period, although the annual proportion of whales with evidence of ship strikes, compared to the total number of strandings, did not change significantly over time. Fin whales had the highest incidence of ship strikes (all seven strandings of this species), mostly consisting of immature animals with all but one occurring since 2002. Six gray whales suffered “possible antemortem ship strikes”; however, this represented only 6% of gray whale strandings since this species accounted for 80% of large whale strandings; indicating that the number of ship strikes likely reflects their seasonal abundance, rather than a high vulnerability to ship strikes. We recorded one of three stranded humpbacks as ship struck, despite concentrations of humpbacks feeding within shipping lanes. Other species documented with ship-strike injuries were blue (2/2), sei (1/1), sperm (1/3) and Baird’s beaked whale (1/1). We believe the dramatic difference in occurrence of ship-struck whales by species results from a combination of a species’ abundance, vulnerability to ship strikes, and the likelihood of a struck whale being caught on a ship’s bow and brought into waters where it may be discovered. Given the variability in species affected by ship strikes worldwide, awareness and solutions to this type of mortality will require consideration of differences in species vulnerability by region.