Status of the White-beaked Dolphin, Lagenorhynchus albirostris, in Canada

White-beaked Dolphins are common and abundant in the north Atlantic. Abunda nce appears greater in northeastern areas compared to the northwestern Atla ntic where its range extends from Davis Strait to the Hague Line on George' s Bank, and into U.S. waters. Relationships between populations observed in different areas are not known. Total or local populations are not known to be reduced or depleted. The biology and ecology of this species has been i ncompletely studied. It occurs in social groups ranging from dozens to hund reds of individuals: there is some indication that groups may segregate bas ed on age/maturity. Sexual maturity occurs in females at lengths from 1.74 to 2.49 m; 50% are mature at 2.42 m. Males are larger at sexual maturity (2 .51 to 2.57 m). Factors limiting northwestern Atlantic White-beaked Dolphin s may include hunting. incidental entrapments in fishing gear, ice entrapme nts and, possibly, pollution. Such factors should be monitored carefully bu t are not, at present, believed to have substantial impacts on the species, although there may be reduction of some local populations. Factors such as ice entrapments, parasites, infections. mass strandings and predation are recognized as naturally occurring mortality and are not presumed to normall y limit the species. There is no evidence of any major threat to this speci es in zones under Canadian jurisdiction. However, careful monitoring of hun ting activities in Labrador is recommended and fisheries by-catches should be carefully monitored.