Direct and Indirect Effects of Oil on Ringed Seals ( Phoca hispida ) of the Beaufort Sea

• Published in: Journal of the Fisheries Research Board of Canada
• Main Authors: Geraci, Joseph R., Smith, Thomas G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1976
• Subjects: Northwest Territories; Norman Wells; Magdalen; Beaufort Sea; Harp Seal; Phoca hispida
• Online Access: http://dx.doi.org/10.1139/f76-252; http://www.nrcresearchpress.com/doi/pdf/10.1139/f76-252

Ninety-six ringed seals (Phoca hispida) were taken from nets at Brown’s Harbour, Northwest Territories in the fall of 1974. Comparison with two other net samples from 1971 and 1972 revealed a lower proportion of young-of-the-year and a lower mean weight of seals in all age-classes. Six seals immersed in Norman Wells crude oil for 24 h at the field netting site suffered only transient eye problems and minor kidney and possibly liver lesions; no permanent damage was observed. Three seals transported to the University of Guelph all died within 71 min after oil was introduced into their pool. Hematologic and blood chemical studies indicate that death was caused by oil superimposed on the stress of captivity. Six, 3–4 wk-old wild whitecoat harp seal (P. groenlandica) pups at the Magdalen Islands, Quebec, were coated with crude oil. No significant differences in core body temperatures were noted and no deleterious effects were observed. Five captive ringed seals at Guelph were subjected to a cumulative dosage of Norman Wells crude oil fed with their fish food. High dosage (75 ml) and low dosage (25 ml) of crude oil were also fed to two groups of six harp seal pups. No significant lesions or behavioral changes were noted. These experiments were of an acute nature and reflect the effects of a brief contact with oil only. Effects of longer contact as would probably be the case in an offshore oil well blowout situation are discussed. Possible effects of large-scale offshore oil fields are also considered.