Postmortems and helminthological examinations were performed on beached seabirds killed by oil spilled from a grounded freighter at Ishikari, Hokkaido, Japan in November 13, 2004. The carcasses were covered with crude oil, but they had adequate subcutaneous fat levels. Gross pathological findings consisting of gastric ulcers, pulmonary edema, enlarged spleens and blackish liquid contents in the digestive tracts suggested that they had a rapid progression to death caused by a loss of ascending force, hypothermia and dehydration. Although the visceral organs had degenerated, no direct evidence of mortality caused by ingesting oil was observed. However, extensive acute inflammatory reactions caused by large numbers of mature and immature nematodes (Contracaecum rudolphii) deeply penetrating the gastric walls was observed in two of the birds. Helminthological investigations were conducted on 21 birds from six species, namely: Phalacrocorax capillatus, Aythya marila, Cerorhinca monocerata, Synthliboramphus antiquus, Aethia cristatella, and Brachyramphus perdix. Thirteen helminth species were obtained and identified, including eight nematodes (Eucoleus contortus, Baruscapillaria mergi, B. rudolphii, Amidostomum acutum, C. rudolphii, Tetrameres fissispina, Cosmocephalus obvelatus and Stegophorus stercorarii), three trematodes (Aporchis sp., Hyptiasmus sp. and Renicola sp.), one cestode (Diorchis nyrocae) and one acanthocephalan species (Andracantha phalacrocoracis). Of these, B. rudolphii from S. antiquus, C. rudolphii and Renicola sp. from A. cristatella, and C. obvelatus and Renicola sp. from B. perdix were first host records. Additionally, B. rudolphii was the first geographical record of this species in Japan.
Postmortem and helminthological examination of seabirds killed by oil spilled at Ishikari, Hokkaido, Japan, in November 2004
6. ROH2015Yoshino.pdf
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