Algae blooms' sudden spread stumps scientists
Peter Fimrite
SF Chronicle
11/27/2011
Marine scientists are trying to find out why previously unknown blooms of toxic algae are suddenly proliferating along the California coast, killing wildlife and increasing the risk of human sickness.
The mysterious blooms have recently been bigger and have occurred more frequently than ever before, an alarming trend that a team of scientists led by UC Santa Cruz is attempting to figure out.
"It is a huge problem for wildlife," said Raphael Kudela, a professor of ocean sciences at UC Santa Cruz and the lead scientist for the study, which began last week. "We've seen a lot more of what we consider unusual events. It's not always the same organism, but new things keep cropping up. The million-dollar question is: What exactly is the change in the environment that these things are linked to?"
The danger was disturbingly apparent starting in August when a deadly red tide killed tens of thousands of abalone, sea urchins and other mollusks along the coast in Sonoma and Mendocino counties.
Scientists will deploy an array of sophisticated ocean-monitoring technology, including robotic gliders, a network of underwater sensors and satellite observations, during the five-year, $4.3 million study. The project shoved off using an $800,000 grant from the National Oceanic and Atmospheric Administration.
Research focus
The researchers will look at the rare species found in the red tide, known as Gonyaulax spinifera, which creates a biotoxin that kills shellfish.
But the primary focus will be on a separate single-celled diatom known as Pseudo-nitzschia. This algae, which was not part of the recent red tide, produces domoic acid, which Kudela said has rapidly become the single biggest biological threat along the California coast.
Pseudo-nitzschia was first identified in the Monterey area in 1991 and in Southern California in 2003. It is toxic to both humans and marine mammals, and although it is normally associated with springtime conditions, Kudela said it has now begun to appear at other times of the year.
The blooms quickly cover large areas and the toxins accumulate in shellfish, mussels, anchovies, sardines and other filter feeders. The domoic acid is poisonous to humans and marine mammals, particularly sea otters, that eat affected shellfish.
People can contract amnesic shellfish poisoning, which causes nausea, vomiting, dizziness and, in severe cases, disorientation, seizures, coma and even death.
It is a big problem for oyster farming and offshore aquaculture, Kudela said, and a primary reason for yearly bans on shellfish harvesting.
"It's quite common. We have toxin in the water pretty much every year, and every couple of years we have a big event, where a lot of birds are dying and sea lions are found dead on the beach," Kudela said. "There is a good monitoring program in California, and if that program didn't exist, then we would probably have more people getting sick."
Monitoring blooms
The plan is to compare conditions in Monterey Bay and along the San Pedro Shelf in Southern California, both hot spots for toxic blooms.
Deep ocean upwellings, river outflows, and agricultural and urban runoff will be looked at during the study. The work is a collaboration of UCLA, the University of Southern California, Moss Landing Marine Laboratories, the Monterey Bay Aquarium Research Institute, the Southern California Coastal Water Research Project, and NOAA's Center for Coastal Environmental Health and Biomolecular Research.
