Monterey Bay researchers use underwater robots to track toxic algae

By Sandeep Ravindran

Scientists are tracking toxic algal blooms in Monterey Bay using a combination of ships, underwater robots, and floating instruments. The idea is to be able to follow marine organisms as they move around in ocean currents, said Jim Bellingham, chief technologist at the Monterey Bay Research Institute.

"This is one of the biggest, toughest, problems out there," said Bellingham.

The project is a collaboration between MBARI and several other institutions and agencies, including UC Santa Cruz, the National Oceanographic and Atmospheric Administration, the Naval Research Laboratory, Cal Poly-San Luis Obispo, and NASA's Jet Propulsion Laboratory. It began earlier this month and ends Oct. 29.

In the current experiment, researchers track different types of algae in hopes of predicting when they bloom and when they release harmful toxins, said John Ryan, an oceanographer at MBARI.

They initially found large blooms of the toxic algae Pseudo-nitzschia australis, but these have decreased in intensity over the past few weeks, replaced by another organism that doesn't produce toxins, said Francisco Chavez, a senior scientist at MBARI.

But Pseudo-nitzschia may be making a comeback in the northeast part of the Bay, said Ryan. This area is relatively sheltered from ocean currents, allowing the algae to persist and form large blooms, which appear as patches on the ocean surface.

The algae come and go depending on the presence of nutrients in the water, said Chavez. When nutrients are pushed up to the surface by currents, the algae begin to grow. They can double their population in a day, and form large blooms in three to five days.

The Pseudo-nitzschia that the group found was producing large amounts of a toxin called domoic acid.

Both the algae and the toxin have been found in Monterey Bay for nearly 20 years. The toxin becomes concentrated in fish and shellfish and can harm marine birds and mammals that feed on them. The toxin can also cause amnesiac shellfish poisoning in humans who eat the shellfish.

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