“One of the things that is clear is there’s a lot of variation from year to year along the Pacific Coast, and some of that is tied into natural patterns, like El Niño,” Mantua said. “But what we saw in 2014, ‘15 and the first part of ‘16 was warmer than anything we’ve seen in our historical records, going back about 100 years.”

Notable impacts for the North Coast included last year’s persistent, widespread “red tide” — a bloom of Pseudo-nitzschia, a single-celled organism that thrives in warm water and produces a neurotoxin called domoic acid. In addition to contributing to fatalities among sea lions and other pinnipeds, the toxin shut down last year’s Dungeness crab fishery for 4½ months, including the lucrative holiday season, pushing many in the North Coast’s commercial fleet to the brink of insolvency.

The crisis isn’t over. Lingering toxicity along the California coast continued into early fall this year, though in a more localized distribution pattern, UC Santa Cruz Professor of Ocean Health Raphael Kudela said during an October public hearing on fisheries and aquaculture.

Warmer than usual water also is believed to have contributed to the collapse of the bull kelp forest off Sonoma and Mendocino counties, along with an explosion of purple urchins that have devoured remaining plant life. The urchins, in turn, are out-competing red abalone, the shellfish that attract thousands of sport divers and pickers each year to the Sonoma and Mendocino coast.

Evidence of starvation in abalone populations prompted authorities to impose new restrictions in the sport abalone fishery next year to limit the catch. The commercial red urchin fishery is suffering, as well, as the larger, marketable red urchins starve.

Meanwhile, the commercial salmon harvest, California’s most valuable ocean fishery, continues to suffer, with spawning populations reduced significantly by the state’s prolonged drought.

Mass-starvation events have hit a spectrum of other West Coast marine wildlife, mostly due to the collapse of food chains brought on by warmer ocean water.

Large dieoffs of Cassin’s auklets, a tiny seabird, were first noticed when dead birds began washing ashore in fall of 2014. A year later, it was malnourished and dead common murres that were found adrift.

Juvenile California sea lions, Guadalupe fur seals and other marine mammals have suffered for several years, as well, both from starvation and, to a lesser extent, from domoic acid poisoning.

The dieoff California sea lions, declared an “unusual mortality event” by scientists in early 2013, has taken a toll on the population, especially the young, with Southern California strandings peaking last year at a record-breaking 4,000, according to the NOAA Fisheries. About a third of the sea lions rescued received treatment at the Sausalito-based Marine Mammal Center.

Researchers believe nursing mothers had been unable to find enough forage, like sardines and anchovies, to properly nourish their young.

The situation for sea lions and seals — mammals known as pinnipeds — appears to have improved somewhat this year, though sea lion strandings were still above 2,000. And there’s been encouraging news on the condition of pups surveyed this fall at Southern California birthing colonies, suggesting food availability may have stabilized somewhat as the warm blob relents, researchers said.

“The short story is that the warm ocean temperatures have moderated, but it’s still noticeably warmer than normal in a narrow strip right along the coast, the entire coast, of North America,” said Nicholas Bond, a research meteorologist with the University of Washington who first coined the term to describe the huge mass of warm water offshore.

There’s some reluctance among scientists and fishermen to predict what comes next.

Washington state fisherman Ron Anderson, who came south to catch crab because northern fisheries remained closed, said the ocean temperature had dropped 6 degrees since he and his crew arrived in the North Bay around Nov. 1.

Another crabber, Bob Monckton of Santa Rosa, said he’d recently seen another harbinger of cooling conditions. “I’ve seen more anchovies out there than I’ve seen in a while,” he said.

But it’s unclear how quickly or if the ocean will return to “normal,” or even what normal would be, given the relatively short period of time during which scientists have monitored conditions historically.

“Even when temperatures moderate,“ Bond said, “it takes a while for the biology to respond, so it’s still a fairly disrupted ecosystem.”

“But all that being said, I think the event is winding down, and — probably some time at the end of winter, spring next year — it will be kind of just a distant nightmare, rather than a current bad dream.”

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.