Ash may kill ocean life

We may not see it for some time, but the adverse effects on coastal marine life resulting from last month’s onslaught of wildfires could be substantial.

Marine biology students at OCC have documented a trend in the lowering levels of plankton off the Orange and south Los Angeles county coasts since blazes broke out Oct. 21 between Santa Barbara and San Diego.

“We’re trying to figure out what the fires did to our offshore waters,” said Dennis Kelly, a marine biology instructor at the Costa Mesa community college.

A number of the classes, including Kelly’s, collected ocean water samples from the Los Alamitos Bay in south Long Beach in the weeks before and during the fires.

Kelly’s class set out again Thursday afternoon to grab samples from the waters off Long Beach to gather more samples now that the soot has settled.

What they have found so far should make people nervous.

“Ash and some of the chemicals [deposited in the waters] have significantly diminished the plankton in the coastal waters,” Kelly said.

The longterm effect may be that many marine larval animals will not reach adulthood and therefore will not replace animals that die or are eaten.

Such effects usually take months to years to affect fish. Kelly predicts a faster spread through the food chain due to the heavy amounts of ashy sediment present in the post-fire plankton samples.

“When we collected after the fires there were huge chunks of ash; it clogs the plankton and suffocates them,” Kelly said. The school keeps plankton records for the last 20 years, but it only took looking back five years for Kelly to notice the unfavorable results.

“From the records, we know how many there are and how many there should be,” Kelly said. “It jumps off the page at us really quick.”

Plankton populations have dropped to 20% of the norm, Kelly added. That’s an 80% decrease.

“The last time we saw something this dramatic was the 1989 American Trader Oil Spill,” Kelly said, referring to the spill off the coast of Huntington Beach where a tanker vessel discharged 10,000 barrels of oil into Southern California waters.

Satellite imagery showed the ash traveled 500 to 1,000 miles out to sea, carrying toxic chemicals from burning cars and paint down to Baja California and further. It will circulate throughout the Pacific ocean, Kelly said.

Tom Garrison, another instructor at OCC, noted similar findings on his classes’ outings.

“Our honors lab group had been working on the local plankton, and the samples were badly contaminated with ash,” Garrison stated in an e-mail. “We also noticed very fine droplets of oil in the surface layer — I’ve never seen anything like it.”

Garrison has not yet tested the oil, but said there is a possibility it could be residual from the “rapid burning of pine or other sap-laden wood.”

Orange County has yet to see any rain since the fires, but when it does, much of the ash sitting on roof tops, awnings, sidewalks and other areas will wash into the ocean, according to Garrison.

He predicted a “red tide” plankton bloom resulting from the “nutrient-rich environment” created from the runoff.

“When blooms like this occur, one species usually dominates,” Garrison said. “Maybe you’ve heard of the recent pseudo-nitzschia outbreaks We can hope this won’t be the dominant species, but time will tell.”

KELLY STRODL may be reached at (714) 966-4623 or at [email protected].