Author Topic: algae bloom in nor humboldt  (Read 511 times)

Offline todd

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algae bloom in nor humboldt
« on: January 27, 2011, 07:03:16 PM »

The algae bloom that turned a stretch of surf along Clam Beach into lumpy brown muck recently may actually be a positive sign for the ocean food chain, scientists say.

The algae -- identified Tuesday by Humboldt State University marine botany graduate student Greg O'Connell -- is known for blooming in the surf zone, said HSU marine botany and ecology professor Frank Shaughnessy. The bloom of Asterionellopsis socialis over the past few days is unusually large, Shaughnessy said.

”It's not common locally in my experience,” Shaughnessy said, “at least not in this amount.”

The globs of algae were mistaken for tar balls by some, and the material did resemble oil on the beach, although it didn't carry the characteristic sheen or odor. It was even spotted on Monday by a pilot who photographed the event while flying over Clam Beach, and the U.S. Coast Guard, the California Department of Fish and Game and county environmental health officials all took samples of the stuff when they investigated.

A search through the scientific literature turned up no references that the species of algae is toxic, Shaughnessy said. But the Humboldt County Department of Public Health Environmental Health Division has forwarded a sample to the state Department of Public Health in Richmond to make sure.

Interestingly, the bloom may be indicative of an early burst of ocean productivity. The warm, clear weather of the recent two weeks



could be causing surface water to warm, creating a layer on top of colder water that isn't mixing as it usually does during winter storms, said National Marine Fisheries Service research biologist Eric Bjorkstedt, also out of HSU.
At the same time, mild but steady winds offshore appear to be driving an upwelling event, in which nutrient-rich cold water is driven to the surface, Bjorkstedt said. Upwelling is strongest in the spring and summer, when strong northwest winds help drive cold water to the surface. But upwelling events do happen in the winter, Bjorkstedt said, and are starting to be seen as playing a significant role in jump-starting the food chain.

That's because some of the big copepods -- drifting plankton or plankton living on the ocean floor -- come to the surface in January and February to release their eggs. Should they encounter algae blooms, Bjorkstedt said, they can feed on them and grow bigger, faster. That gets the ocean food chain off to a head start when the main upwelling events of spring and summer begin, he said.

”In effect, you're kind of priming the pump,” Bjorkstedt said.

Plankton is important to bait species, rockfish and salmon, as well as to nesting seabirds and a host of other creatures.

Bjorkstedt said that he's trying to arrange for a cruise this weekend to determine if indeed there are other algae blooms at sea that may indicate good ocean productivity. Most of the research on wintertime upwelling has been done off Oregon, but Bjorkstedt said that researchers are now trying to look at the California current from a more year-round perspective.

That may make the sunny spells that come so infrequently during the winter seem even more precious.

”These sudden breaks in the weather are not just good for our souls,” Bjorkstedt said, “they're good for the ocean, too.”

Todd Stagnaro

Offline NorCal DiverDave

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Re: algae bloom in nor humboldt
« Reply #1 on: January 28, 2011, 01:09:38 PM »
Thanks for the information.
Its good to hear the good side of something like this.


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