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Fish and Marine Life
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MARINE MAMMALS
Indicators
- Body condition and reproductive status of seals and whales
- Disease and contaminant loads in individuals
- Age of first maturity & reproductive rate
- Stock size and range
- Prey quantity and quality
- Quality, temporal and spatial extent of sea ice
- Ambient and anthropogenic noise levels
Current Knowledge
Bowhead whales have an estimated population of 10,470. They arrive at the Beaufort Sea for spring habitat and remain there, widely dispersed, until July; they then form loose groups by mid-August in the south-eastern Beaufort Sea. The Inuvialuit of the western Arctic harvested one bowhead whale in 1991 and another in 1996; there is a potential for additional harvesting licences to be granted.
Beluga whales (pop. about 40,000) arrive at about the same time and follow similar off-shore routes in spring. Beluga whales follow a migration route off the Tuktoyatuk Peninsula, the Mackenzie Estuary's three main bays; they then move to the Amundsen Gulf area before returning to the Bering Sea wintering areas. The Inuvialuit of the Mackenzie Delta and Paulatuk have harvested 110 belugas over the last 100 years for subsistence reasons.
Ringed and bearded seals are resident species and do not leave the region in the winter like whales do. The availability of stable sea ice is critical to the well being of seals in the Beaufort Sea. The most important factors for bearded seals habitat is the availability of benthic feeding areas and pupping areas. The ringed seal population is thought to be at least 650,000. The Inuvialuit harvest about 500-600 ringed seals per year. The size of the bearded seal population is unknown; although observations tell scientists that it is considerably lower than the ringed seal's population.
Current Monitoring
- Mackenzie Delta Beluga Harvest Monitoring - Fisheries Joint Management Committee (FJMC), Esso Resources Canada and Fisheries and Oceans Canada (DFO)
- Bowhead Whale Harvest monitoring - DFO and FJMC
- Beached bowhead whale sampling - DFO
- Ringed seal harvest monitoring - DFO, FJMC and US Minerals Management Service
- Seal and whale disease monitoring - FJMC and DFO
- Seal and whale contaminants monitoring - FJMC and DFO
Gaps and Recommendations
Information about the range, movements, and stock are needed for beluga and ringed seals. Information about the potential impacts of development and climate change/reduced ice cover on marine mammals would be helpful. The cause of death of bowhead whales that washed up annually in the Amundsen Gulf and discovered by Inuvialuit harvesters in the rim communities is unknown.
Monitoring in the following areas is recommended: underwater noise in whale habitats; marine mammal distribution, size, age and maturity. Continued community-based monitoring through harvest based projects has also been suggested. This VC is strongly linked with others such as Water Quality and Quantity.
This summary is based on: A Preliminary State of Knowledge of Valued Compnents for the NWT Cumulative Impact Monitoring Program (NWT CIMP) and Audit. February, 2002; updated February 2005.
For more details, you may also want to look at:
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