New research finds toxic hydrocarbons in B.C. orca population

For the first time ever, researchers have examined liver and muscle tissues in 12 deceased orcas found in the waters around Vancouver Island between 2006 to 2018. The findings are giving us a better understanding of the health of our oceans.

“We call it the canary in the coal mine,” said Juan Jose Alava, principal investigator of the Ocean Pollution Research Unit at the University of British Columbia.

Alava says toxic hydrocarbons produced from fossil fuels were found in every whale sampled.

“So everything goes through the water, the phytoplankton, the herring, the salmon, and then it builds up in the food web until reaching the apex predators, which are the orcas,” said Alava.

Another source of the harmful hydrocarbons is wildfire smoke, inhaled by the surface-breathing mammals.

Also in another first, one of the orcas examined was pregnant at the time of her death. Her fetus also showed traces of the harmful toxins.

“So we observed maternal transfer,” said Alava.

Six transient orcas were tested as well as six resident whales. Those southern resident killer whales have struggled over the years, with the population currently sitting at 75.

Their challenges date back many years, beginning with the legacy of the live-whale capture that essentially eliminated an entire generation of orcas that should have been adding to the gene pool.

“We also have our current day threats and risks which includes acoustic and chemical pollution and of course there’s always the very important one of, are they getting enough to eat,” said Anna Hall, a marine zoologist based in Victoria.

Hall says the report's findings are extremely concerning.

“I think the biggest piece is the pollution that is getting into the killer whales from the wildfires,” said Hall. “There’s everything that we’ve heard about climate change and we’ve been told to expect more wildfires as the climate continues to change, to me that just means are we going to expect more contaminants moving into the marine environment.”

Researchers hope the findings will be used by policymakers to make informed decisions moving forward.

“To really protect the whales and their critical habitat and to mitigate harmful pollution,” said Alava.