Professors compare acid notes
Local educators and their students have been working hard to find out what’s been killing the marine life in Orange County, but with classes about to end one area professor has had to reach out for more help from a research organization in Costa Mesa.
When Orange Coast College professor Dennis Kelly took his class out last week on a field trip, he made a key discovery of a thick concentration of plankton in San Pedro Harbor, a possible source of the domoic acid that’s poisoning hundreds of birds, sea lions and other marine life. But Kelly’s research assistants are nearing the end of the semester, so he called on Steve Weisberg at the Southern California Coastal Water Search Project in Costa Mesa to compare notes and keep the research going.
Kelly has also turned over all of his plankton samples to UC Irvine Professor Peter Bryant. Bryant, a molecular biologist with the university since 1969, has begun coding the DNA of the plankton to identify different species, some that may be more toxic than others.
“When we have an outbreak or something that needs to be identified and don’t have time for the conventional methods,” having the gene sequences on file will greatly speed up the process, Bryant said.
The professor and three of his students have research of their own to accomplish before they can begin sequencing the plankton samples that Kelly provided. Before they handle the plankton they need to become better acquainted with the DNA-coding equipment.
Bryant expects to have his work done by summer’s end.
Kelly and his class found a species of plankton called Pseudo-nitzschia. That substance has been known to produce the deadly acid. It’s particularly dangerous when it gets into the food chain. Humans and animals can suffer short-term memory loss or die if they eat fish, such as sardines and anchovies, with domoic acid in them.
The thing to do in this situation is warn people, Kelly said. “This could be good news since we’re aware of it. Now we can tell people not to eat this fish,” he said.
Kelly has also met with David Caron, A USC professor who is similarly following up the Pseudo-nitzschia lead. Caron found the same closely crammed plankton layer just outside of the harbor mouth but had not yet studied the waters on the other side of the jetties, Kelly said.
The researchers also discussed a number of other sources of the deadly toxin.
Tons of nutrient-rich soil has been deposited just 5 miles off the coast of Newport Beach’s Back Bay because of dredging there. Ocean currents could allow the sediment to spread rather than sink straight down to deeper waters, Kelly said.
It’s also possible that ash from recent fires has drifted into the water and carried with it nutrients for the plankton to eat. Recent storms along the coast have also stirred up sediment, Kelly said. It could be that all of these scenarios could have contributed to the problem, he added.
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