Toxic ocean algae blooms impacting fish populations

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Earlier this week, we reported on how some sea lions are suffering brain damage from toxic algae that has negatively impacted the Dungeness crab population, closing crab season indefinitely. Now KTVU spoke with an ocean scientist who thinks way more than crabs and sea mammals could be impacted as warm water causes toxin levels to continue to rise.

The Ocean Sciences Lab at UC Santa Cruz has been studying anchovies, a food prized by humans worldwide. and prey for many larger ocean creatures including sea mammals and large fish.
Demoic acid, a brain damaging neuro toxin that comes from warm water algae blooms, is often found in the intestines of anchovies and other sea dwellers that feeds on the algae, but washes out harmlessly in a day or so.

What scientists have now found is different.

"What's new is we found demoic acid in many, many, many new fish that aren't eating the plankton directly. And, it's actually in their muscle tissue, not just in their stomachs. The fact that it's getting into the muscle tissues suggests that it's probably there for much longer than 24 hours," says Raphael Kudela an ocean scientist at UC Santa Cruz.

Nothing found is at or near the danger level. "If it's being sold commercially and it's been tested, it's below the regulatory limit and you're not going to have any problems from eating it," says Professor Kudela.

But this will be the third straight year there have been high toxin levels in our warmer ocean waters,

Should demoic acid levels rise in fish, it could become a problem for humans similar to too much mercury in fish.

"It's by far, the most toxins that we've ever seen up and down the west coast and the most toxins we've seen in many, many types of animals," says Kudela.

With toxin levels now putting the crab season on indefinite hold, something else now looms large — the potential that these algae blooms affect the fish population.  Kudela says it would be devastating, to the already damaged fishing industry, but could also change the American diet.