What caused killer algal blooms on the Washington coast?

The mysterious bird-killing algae that coated Washington’s ocean beaches this fall with slimy foam was the biggest and longest-lasting harmful algal bloom in Northwest history. Now the phenomenon that killed at least 10,000 seabird has scientists consumed by questions: Was it a rogue occurrence, rarely if ever to be repeated, or a sign of some fundamental marine-world shift? And did we cause it?

By Craig Welch, Seattle Times environment reporter The mysterious bird-killing algae that coated Washington’s ocean beaches this fall with slimy foam was the biggest and longest-lasting harmful algal bloom to hit the Northwest coast. Now the phenomenon that killed at least 10,000 seabirds — more than any known event of its kind — has scientists consumed by questions: Was it a rogue occurrence, rarely if ever to be repeated, or a sign of some fundamental marine-world shift? And did we cause it? Answers may come slowly. “You can think of it as a jigsaw puzzle with 500 pieces, but we only have about 50,” said Julia Parrish, a University of Washington fisheries and oceans professor. This much is known: Toxic blooms of microscopic phytoplankton sometimes called red tides are exploding worldwide, even along pristine waters like the Northwest coast. And the organisms behind these blooms can behave unpredictably, revealing how little we know about the sea. The culprit this fall was a mushroom-shaped single-celled species, Akashiwo sanguinea, that has bloomed in Puget Sound, Chesapeake Bay and saltwater from Europe to Australia and Japan without incident. But something here this time caused the cells to multiply rapidly and break open in a toxic foam. It’s been recorded happening only once before — on a smaller scale, in Monterey Bay in California, in 2007. Researchers are trying to gauge whether warming surface waters or more corrosive seas might have played a role in the two blooms, or whether they were caused by a collision of shifting currents and natural atmospheric and weather cycles like El Niño. Or maybe it’s all of the above — or something else. “We haven’t ever seen this before and now we’ve had two events in two years,” said Raphael Kudela, an ocean-sciences professor and toxic-algae expert at the University of California, Santa Cruz. “If it happens again, I’ll be concerned. Four times and I’ll be really concerned.” …

Trying to crack an ocean mystery: What caused killer algal blooms? via Apocadocs