Vancouver, B.C. – Today, Fisheries and Oceans Canada (DFO) announced in a tweet that the killer whale calf found dead on the west coast of Vancouver Island on Dec. 23 was a Bigg’s killer whale of the Gulf of Alaska transient population. DNA analysis, performed by scientists at the Vancouver Aquarium Marine Science Centre using a tissue sample provided by DFO, enabled the determination of the female calf’s ecotype.
“Tracking the number of births and deaths in each population is key to monitoring the health of these killer whales; in order to do this, you need to know where the whale came from,” said Carla Crossman, molecular and marine biologist with the Vancouver Aquarium. “They’re iconic on our coast, but they’re also considered a sentinel species. Knowing how they’re doing tells us a lot about general ocean health.” Lab results identified the calf as having the GAT1 haplotype by comparisons to known DNA samples previously collected by Dr. Lance Barrett-Lennard, head of the Vancouver Aquarium’s Marine Mammal Research Program.
The Gulf of Alaska Bigg’s are separate from those that inhabit the waters off B.C., and less is known about them. The whales do spend time in our waters, but how much is unclear. Like B.C.’s Bigg’s killer whales — which are listed as threatened under Canada’s Species at Risk Act — Gulf of Alaska transients are long-lived upper trophic-level predators that are considered to be at risk due to small population size, low reproductive rate, and high levels of chemical contaminants. Because they rely on stealth and passive listening to detect prey, they are also threatened by acoustic disturbance from underwater noise. Other threats include biological pollutants, trace metals, physical disturbance, toxic spills, collisions with vessels, interactions with fisheries and decreased prey availability.
The genetic analysis of the calf was run at the Vancouver Aquarium’s new Conservation Genetics Lab, located in East Vancouver and opened as part of its Coastal Ocean Research Institute, launched in 2014. The Research Institute is working to establish a baseline for the current condition of our marine ecosystems, and to deepen our understanding of future changes.
“We’re committed to building knowledge about ocean ecosystems; B.C.’s whales and other marine mammals are a priority topic for us,” said Andrew Day, executive director of the Coastal Ocean Research Institute. “We’re happy to help provide much-needed information.”
The cause of the calf’s death is still unknown. Killer whale calves have poor survivorship in their first year, with scientists estimating it at less than 50 per cent. A necropsy of the young whale was conducted on Christmas Day; results of tissue-sample testing are still to come.
Vancouver Aquarium Coastal Ocean Research Institute
Established to measure and monitor the health of coastal ecosystems on Canada’s West Coast, the Coastal Ocean Research Institute, part of Vancouver Aquarium Marine Science Centre, is a multi- disciplinary, collaboration-based Institute established to increase dialogue and inform policy. The Research Institute is grateful for its generous founding funding partners Sitka Foundation and North Growth Foundation.
Vancouver Aquarium Marine Science Centre
The Vancouver Aquarium Marine Science Centre is a non-profit society dedicated to the conservation of aquatic life. www.vanaqua.org