Since 2019, an international group of scientists, field biologists and volunteers have been investigating a mysterious phenomenon known as an Unusual Mortality Event, or UME, that’s been killing off one the world’s heartiest survivors: the northern Pacific gray whale. In that time, the number of stranded gray whales has reached 500 — a fraction of the many thousands that likely died and sank to the ocean floor.
While its underlying cause remains elusive, many researchers point to the conditions in and around a rapidly changing Arctic Ocean. The retreating ice sheet, warming waters and a shifting ecosystem may be decimating gray whales. Understanding these threats to the whales could reveal an even broader ecological impact — and another piece of Earth's biome rewritten by climate change.
Before the 2019 UME, the eastern North Pacific gray whale's population had grown to over 25,000, making it the poster child for marine mammal recovery. Commercial whaling had nearly wiped out the Pacific grays until the practice was banned in the US in 1971 and then internationally in 1986 under the International Whaling Commission. In 1994, the whales were no longer endangered.
Part of their success story is that they're a resilient species. The Atlantic variety of gray whale was deemed extinct in the 1700s. But in 2021, a lone male gray whale was found hungry and swimming in the Mediterranean Sea. Surviving as a species on this planet for some 200,000 years can have that effect. Gray whales have learned how to make it.
“My money’s always on gray whales,” said Sue Moore. “As I’ve said — now maybe too many times — they don’t call them robustus for nothing. They are a robust species.” She’s referring to their scientific name: Eschrichtius robustus.
As humans we should stop hunting them, hitting them with ships, and entangling them in fishing gear, she said. But in terms of responding to a warming climate, when compared with humans, Moore’s bet is on the whales.
There’s no better example of the whale’s hardiness than a small tribe of grays that stopped migrating altogether. Unlike their ambitious cousins, these gray whales stay in the Vancouver Island habitat. They’re known as "Sounders" because they live year-round in the northern Puget Sound area.
Read the full article in CNN.