Gray whales appearing in staggering numbers off California. Why that may mean trouble
Californians have been wondering why the gray whales keep coming. For several years, gray whales have been showing up in unusual places along the coast of the Golden State, dangerously close to shore.
In gray whales’ annual migration from Baja, Mexico, to Alaska to breed, it seems the whales have been veering off course.
But why?
From 2010 to 2017, only about 1 or 2 gray whales came into California’s San Francisco Bay every year, Bay Area News Group reported.
Between 2018 and 2023, however, scientists confirmed at least 71 gray whales in the Bay, according to the outlet. Some of those whales dangerously lingered for as long as two months, leaving them exposed to the risk of being hit by all kinds of vessels.
Similarly, Southern California has noticed a steep uptick in gray whale sightings and at off-times, according to the San Diego Natural History Museum.
And not all the whales Californians are seeing are alive. Recent research published in the peer-reviewed journal PLOS One spotlighted the increase in dead gray whales washing up on shore since 2018. The creatures had all sorts of causes of death, including starvation, vessel strikes, orca attacks and entanglements in fishing gear.
The study also highlights a drop in food availability in gray whales’ Arctic and sub-Arctic migratory destinations.
The National Oceanic and Atmospheric Administration called the die-off an Unusual Mortality Event, which officially lasted from December 2018 until November 2023.
“The UME involved 690 gray whale strandings, including 347 in the United States, 316 in Mexico, and 27 in Canada. Strandings occurred from Alaska to Mexico along the west coast of North America, including in the whale’s wintering, migratory, and feeding areas.”
NOAA experts concluded the unusual die-offs were caused by ecosystem changes in the whales’ Arctic feeding areas “that led to changes in food, malnutrition, decreased birth rates, and increased mortality all documented during the UME.”
Bill Keener from The Marine Mammal Center believes the rerouting of the whales and the die-offs have a common cause.
“We think it has a lot to do with the fact that the whales haven’t been getting enough food,” he told Bay Area News Group. “They may be weak and resting for a while, or they may be looking for an alternative food source.”
This story was originally published June 26, 2024 at 2:21 PM with the headline "Gray whales appearing in staggering numbers off California. Why that may mean trouble."