Status of the sperm whale, Physeter macrocephalus in Canada

The Sperm Whale (Physeter macrocephalus) is the largest of the toothed whales. Members of this species are extreme, or distinctive, among cetaceans in many ways which include their large brain size, sexual dimorphism, diving behaviour, social organization, communication system and ecological significance. They occur in all the deeper waters of the world's oceans that are not ice-covered, although females are generally restricted to areas where surface temperatures are warmer than 15 degrees C and depths are greater than 1000 m. Sperm Whales range widely with no clear divisions between populations. Sperm Whales were depleted during two massive, world-wide hunts (peaking in approximately the 1840s to the 1860s and the 1950s to the 1970s). The current world population likely numbers a few hundred thousand, but there are considerably fewer Sperm Whales now than there were before whaling. Recovery of the population is slow because of a very low reproductive rate, possibly compounded by thr lingering effects of a socially disruptive hunt concentrated on large males. Sperm Whales are found off both the east and west coasts of Canada with particular concentrations at the entrance to the Hudson Strait, on the Scotian Shelf and west of Vancouver Island. Both sexes occur off western Canada, but females only occasionally use the southern most waters off Atlantic Canada. Although no immediate threats to Sperm Whale populations are known, these animals are vulnerable to particular kinds of human disturbance, and populations may be threatened, in the long term, by increasing levels of pollutants in the oceans.