September 16, 2025 — It’s well documented by now that the marine heatwave that hit the Pacific Ocean in 2014 had devastating effects on Alaska’s marine ecosystem and commercial fisheries.
Now, scientists are uncovering long-term impacts on Alaskan killer whales specifically – a harbinger as marine heat waves become more frequent and severe with climate change.
“We’ve learned that females that were growing during those heat wave years grew to smaller sizes,” said John Durban, a senior scientist with the New England Aquarium in Boston who has been studying killer whales in the Gulf of Alaska for two decades.
“If you’re smaller as a whale, it means you don’t have as much fasting endurance, you can’t store as much blubber,” Durban added. “So if you go through lean times, you’re less likely to bring a successful pregnancy to term.”
Durban has been partnering with the Alaska-based nonprofit North Gulf Oceanic Society to monitor several hundred resident, salmon-eating killer whales in the Gulf of Alaska. He flies drones over the water, which capture images of the whales from more than 100 feet in the air.
Those images allow researchers to measure how individual whales are developing over time.
The North Gulf Oceanic Society has been monitoring killer whales in the Gulf for more than four decades. Durban said that work became particularly important in the aftermath of the Exxon Valdez oil spill, which correlated with an “unprecedented” number of whale deaths among two pods that were exposed to the spill, according to NOAA.