Can We Have More Whales and Fewer Whale Strikes?
Anchovies sparkled and seawater sprayed from the crusty maws of gray whales as they burst through the surface, again and again, off the coast near Pacifica, fifteen miles south of San Francisco. Groups of up to six gray whales devoured fish for 28 days straight in June 2022.
This was no ordinary feast. For those who know gray whales, it was odd for a couple of reasons.
First, gray whales are known for being the only baleen whales that primarily feed at the bottom of the ocean, eating krill such as crustaceans, shrimp, and worms. They turn sideways in shallow coastal waters with one fin poking up in a behavior known as “sharking.” Then they rake their bristly, sieve-like comb teeth along the ocean floor to scoop up mouthfuls of invertebrates, sifting them out of the mud with their baleen. And there’s a lot of whale to feed: gray whales can grow to be 40 to 50 feet long — as big as a full-length school bus — and can weigh more than 35 tons. Adult gray whales can hoover up 660 pounds of food per day.
Gray whales also journey farther than other species. Every year, gray whales embark on a 12,000 mile round trip voyage — the longest migration of any mammal. Gray whales often fast through the four months between leaving their summer feeding grounds in the Arctic, journeying to breed and raise calves in Baja California in winter, and coming back again. Researchers and whale watchers typically expect gray whales to cruise past California without stopping for as much as a snack along the way.
So why were whales in Pacifica bucking these norms?