Marine heat wave impacted humpback whale population: study

Marine heat wave impacted humpback whale population: study

Humpback whales are a significant draw off B.C. waters, but a new study is raising concerns about the effect of warming oceans on the health of humpback whale populations.

Jackie Hildering is a humpback researcher with Canadian Pacific Humpback Collaboration, one of the 46 organizations involved in the study.

“We had some localized sense in seeing emaciated whales having lower reproduction rates in certain rates,” Hildering said. “Our colleagues in Alaska really saw the impact of this heat wave on humpback whales.”

The study determined that the population of North Pacific humpback whales declined by 20 per cent between 2012 and 2021.

The main reason?

The marine heat wave known as “the blob” that impacted our waters from 2014 to 2016.

The warmer water led to a reduction in plankton, a key food source for the whales according to humpback researcher, Tasli Shaw.

“They need to eat a lot of food everyday, well over a thousand pounds. So when they are not getting enough to eat, it will affect their survival rates, and also likely their calving rates as well,” Shaw said.

In 2012, an estimated 33,500 humpbacks were found in the North Pacific, growing at an annual rate of six per cent.

Almost decimated by whale hunting, which was banned in 1976, the humpback comeback resulted in many sightings along the coast, but scientists say that increase in whales could have been the result of a geographical shift, not necessarily a healthier population.

Mark Malleson has spent the past 28 years taking tours out whale watching for Prince of Whales.

“The humpbacks,it’s been incredible seeing the return of the humpbacks in the last 20 years.”

He says humpbacks are often in the waters off Victoria, but the study’s findings are concerning.

“I was a bit surprised when I heard that population in the North Pacific had declined. I was a bit surprised. It’s a concern with global warming. It’s a concern for sure. These animals are shifting to other areas,” Malleson said.

The federal body overseeing species at risk in the country now lists humpbacks as “a species of special concern.”

That’s because even though the species is recovering, it’s still not secure.

READ MORE: Humpback whales, Island-based marine society featured in BBC’s ‘Planet Earth III’

Mary GriffinMary Griffin

Recent Stories

Send us your news tips and videos!