Acid-producing plankton found

While leading a field trip near the San Pedro harbor, Orange Coast College instructor Dennis Kelly stumbled upon an important biological discovery.

Kelly just may have happened upon the source of the domoic acid that has been killing sea lions and birds along the California coast. Technically, it’s called “Pseudo-nitzschia.”

No one yet knows why the plankton produce the deadly toxin.

Kelly returned with another class on Thursday to confirm the discovery. Living five meters deep and measuring one-meter in depth, the plankton was so thick no light could pass through it.

During the spring, the plankton has been known to produce domoic acid, a neurotoxin that causes short-term memory loss and eventually death to animals and to people if they eat the contaminated marine life.

The acid has killed hundreds of sea lions and thousands of coastal birds since April.

Kelly said that recent storms may have churned the water, creating a nutrient-rich, fertile environment for plankton to grow in.

The lack of rain between the large storms did nothing to keep the plankton population down, leading to enormous concentrations of phytoplankton in shallow water, Kelly said.

“If it comes up at night when the fish and sea lions feed all bets are off,” Kelly said, adding that this could wipe out the local population of sea lions, birds and dolphins.

“The only thing we can do now is warn people,” Kelly told his class during Thursday’s outing. He added that the most likely ways for people to ingest the toxin is through sardines or anchovies.

Most of the animals cannot be saved once they’re poisoned, he said. The sea lions “freak out” when they ingest the domoic acid and swim to shore, while the birds often end up flying into things, Kelly said.

The plankton finding, a timely discovery, was only part of the excursion. The class of 12 separated into five groups and compiled sediment, sea life, water, and navigational readings along with plankton samplings.

Levin Eliopulos and Michael Marini were in charge of determining how clear the water was during the outing to the Port of Los Angeles Harbor in San Pedro.

They did this by dropping a white marker into the water until they could not see it anymore.

Cory Freeman and Hank Seaman gathered data on the types of animals found in the harbor.

A large net dropped off the back of the research vessel gathered flounders, shrimp and scores of other marine life, which were measured and tallied by Jordan Eden.

Eden, 21, of Costa Mesa was assigned the task of collecting every group’s data and compiling it into one presentation. He will write a conclusion based on the findings that will be posted in OCC’s applied sciences building.

“I hypothesized that because of the high and low levels of rain, a lot more plankton would be produced,” Eden said.

The class has not yet tested Newport Harbor’s waters, and it looks unlikely that they will, Kelly said. Meanwhile, the plankton samples were sent to UC Irvine researchers who will conduct DNA tests to determine the number of phytoplankton species in local waters.

The floating carcass of a sea lion seen on the way back into port sharply reminded the students of the importance of their studies.

“That’s [the third] I’ve seen in the last month,” boat safety instructor Bob Adams said.