The west coast's shellfish industry has been shut down by an unprecedented toxic algal bloom. The toxic algae extends from California to the Canadian border. Shellfish in California, Oregon and Washington state is unsafe to eat. The proximal cause is the extraordinarily warm east Pacific ocean where abnormally high sea surface temperatures have inhibited mixing, trapping nutrient rich water and toxic algae in a narrow coastal zone.
East Pacific ocean surface temperatures are much above normal on 16June2015. Northerly winds along the Pacific northwest coast caused cool nutrient rich water to well up in a very narrow coastal zone. The very warm water mixes very little with the cool upwelled water, trapping it and the toxic algal bloom along the west coast.
"It appears to be the largest we've seen in terms of severity and magnitude," said Michael Milstein, spokesman with NOAA Fisheries.
He said when the ocean is warm and not "mixing," algae grow and produce a toxin, which is then eaten by sardines, anchovy and other fish that feed on the algae.
NOAA has mobilized extra scientists to monitor and study the toxic bloom.
NOAA will do an extensive investigation to understand the relationship between the toxic bloom and the extraordinarily warm temperatures in the northeast Pacific, but their scientists have already published many reports that link warmer waters to reduced mixing. Reduced ocean water mixing is one of the major known destructive impacts of global warming. This extreme toxic bloom was predictable based on the extremely high water temperatures.
NOAA Fisheries mobilizes to gauge unprecedented West Coast toxic algal bloom
Offshore survey will measure extent and severity of largest harmful algal bloom in more than a decade NOAA Fisheries’ Northwest Fisheries Science Center in Seattle has mobilized extra scientists to join a fisheries survey along the West Coast to chart an extensive harmful algal bloom that spans much of the West Coast and has triggered numerous closures of important shellfish fisheries in Washington, Oregon and California.
The bloom stretches from the Central California Coast north to Washington and possibly Alaska ,and involves some of the highest concentrations of the natural toxin domoic acid ever observed in Monterey Bay and off the Central Oregon Coast. In early June elevated toxin levels led shellfish managers to close the southern Washington Coast to Dungeness crab fishing, the largest-ever closure of Washington’s multi-million-dollar crab fishery.
“We’re taking advantage of our active surveys to focus research on a serious concern for coastal communities and the seafood industry,” said Eileen Sobeck, assistant administrator for NOAA fisheries. “The better we understand what’s happening out on the water, the better we can address the impacts.”
While localized blooms of marine algae that naturally produce domoic acid are common in spring, the bloom that began earlier this year has grown into the largest and most severe in more than a decade. Sardines, anchovy and other fish that feed on the algae and other microorganisms known as plankton can accumulate the toxin, in turn poisoning birds and sea lions that feed on them.
“This is unprecedented in terms of the extent and magnitude of this harmful algal bloom and the warm water conditions we’re seeing offshore,” said Vera Trainer, manager of the Marine Microbes and Toxins Program at the Northwest Fisheries Science Center (NWFSC) in Seattle.
In mid-May a brief upwelling event along California's central coast led to an extreme toxic algae bloom in Monterey bay that caused a sudden fish die off.
Stanford University marine biologists blogged the effects of the extraordinarily high levels of toxic acid found in the fish. Conditions in the bay are improving now but the shellfish is still unsafe to eat.
"We have been following a very big bloom of Pseudo-nitzschia over the past couple of weeks here in the bay, and the amount of associated domoic acid is really extraordinary…
"Yesterday I noticed anchovies washing up on the beach in front of MBARI and [south] as far as I could see. There's also lines of fish scales (anchovy?) marking the high tide line. We picked up some of the dead fish—guts are full of Psuedo-nitzschia frustules and the fish are hot with [domoic acid]. One of the staff went snorkeling off the beach here, and saw the seafloor littered with anchovies. There's lots of birds feasting on the fish—we are seeing some dead birds amongst the fish, so I would guess some are getting hammered with [domoic acid].
"The bloom appears to be most toxic in the southern side of the bay for reasons we don't understand. Heads up to the [Monterey Bay Aquarium] for your seawater intake, and keep an eye out for seizuring sea lions, sick birds, maybe sick otters. You may also see fish washing up…
"Don't eat shellfish or forage fish from [Monterey Bay]—very nasty right now!!!"