Recovery Strategy for the Atlantic Walrus
Walruses are large, gregarious marine mammals which can be distinguished from all other species of marine mammals by their tusks, which are long upper canine teeth, and the moustache of quill-like whiskers. Males grow to about 315 cm and 1100 kg, females to about 280 cm and 800 kg. Females mature at age 5-10 years, males at age 7-13 years. Maximum age in walruses may be greater than 35 years.
Walrus feed mostly on bottom-dwelling organisms such as clams and sea urchins, but are known to occasionally also eat fish, squid and even ringed and bearded seals. Their preferred habitat is shallow water (80 m or less) with bottom substrates that support a productive mollusc community, the reliable presence of open water over the feeding areas, and suitable ice or land nearby on which to haul out, sometimes in large herds.
Historically, Atlantic walruses ranged from the central Canadian Arctic in the west to the Kara Sea (Russia) in the east, north to Svalbard and south to Nova Scotia. Within Canada the extant eastern Arctic population (currently subdivided by the Department of Fisheries and Oceans (DFO) into four populations for management purposes (COSEWIC 2006) of Atlantic walrus ranges from Bathurst and Prince of Wales islands in the west to Davis Strait in the east, and from James Bay in the south to Kane Basin in the north. A fifth Northwest Atlantic population ranged south along the Labrador coast to the Gulf of St. Lawrence, Newfoundland, and Nova Scotia. This recovery strategy follows the original COSEWIC (in press) population separation which identified two Canadian populations for designation: an extant eastern Arctic population, and an extirpated Northwest Atlantic population. It is this Northwest Atlantic population which is on the federal List of Wildlife Species at Risk (i.e., SARA Schedule 1) and for which the development of this recovery strategy is required.
Originally thought to number in the tens of thousands, this Northwest Atlantic population was heavily harvested for at least a hundred years in the 17th and 18th centuries and hunted to extirpation by the late 18th century. The principal threat to existing Atlantic walrus populations is hunting for Aboriginal subsistence. Noise and disturbance from shipping, aircraft, and human activities including oil and gas exploration; contamination from oil spills; entanglement in fishing gear; and disturbance or harvesting of prey populations are potential threats to a re-established walrus population in southeastern Canada. Hunting would be an unlikely threat to a re-established Northwest Atlantic population.
Recovery of the extirpated Northwest Atlantic population is not considered biologically or technically feasible at this time. Individuals are occasionally observed in the area of historical distribution, probably migrants from the eastern Arctic population to the north, but these strays have not supported natural recovery to date. With respect to re-introducing individuals from elsewhere to establish a viable population, suitable habitat may be available but interactions with humans would have to be minimized by site selection or management. Threats could probably be mitigated. It is uncertain that sufficient numbers of mature individuals could be made available from extant populations to support re-establishment, and the challenges of humanely transporting live animals from the remote northern areas where they are found to remote areas in southern Canada are such as to make recovery technically not feasible. Captive breeding is unlikely to be a viable option for contributing to re-establishment.
Although recovery has not occurred based on migrants from the adjoining eastern Arctic population, there is a slight possibility of recovery based on natural migration. Conservation efforts to ensure healthy marine environments in southeastern Canada, along with the prohibitions on killing or harming individuals of this population which is listed as “extirpated” under the Species at Risk Act, would contribute to increasing the possibility of natural recovery. The feasibility determination will be re-evaluated as warranted in response to changing conditions and/or knowledge, in particular every five years as part of the mandatory report on implementation of the recovery strategy.
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