Why eye-popping whale shows off the California coast are the new normal
Peter Winch, a naturalist with the Oceanic Society conservation group, said whales have been especially visible this year because cold ocean upwellings have sprinkled near-shore waters with plankton. The whales swim close to shore for anchovies, which feed on plankton, he said.
“They are taking advantage of anchovy shoals that are numerous around the coast,” Winch said. “The humpbacks have the ability to pick and choose. They can stay out in deeper water and eat krill or they can come in. In the last few years, they have just really clued in on this abundance of anchovies.”
Humpbacks have put on a show this summer inside and outside the Golden Gate — flopping around, waving their flukes and leaping out of the water — a bonanza for whale watchers in tour boats and on dry land that scientists say will remain a regular thing.
The local humpbacks migrate along the California coast past San Francisco on their way to and from their breeding grounds in Mexico and Central America. Unlike gray whales, which generally make a beeline to Alaska, humpbacks move north slowly after giving birth, feeding all along their migration route.
Jared Davis, the captain of the Salty Lady fishing and tour boat, said he and his passengers spotted 50 humpbacks on a trip from San Francisco to the Farralon Islands last month. Boaters there have also seen blue whales, fin whales, orcas, dolphins and porpoises in large numbers this summer.
“When the conditions are good, the whales flourish, and the conditions have been good the last couple of years,” said Davis, who takes people whale watching on the weekend and salmon fishing during the week. “It’s a lot of fun.”
The problem with humpbacks moving close to shore, Calambokidis said, is that boats can hit them or crab pot lines can tangle them up.
A recent study by Point Blue Conservation Science found that ships strike and kill an average of 22 humpbacks a year off the coast of California, Oregon and Washington. About 7,300 vessels pass the Golden Gate every year.
The number of whales entangled in fishing lines off the West Coast has risen sharply in recent years, with 71 cases in 2016 — up from 57 the year before and the most since the National Marine Fisheries Service began keeping records in 1982.
“There has been a dramatic increase in entanglements, particularly in crab pots,” Calambokidis said. The humpbacks, he said, “are arriving earlier in the spring to find prey and feed and that overlaps with the crab fishery.”