Domoic acid poisonings worst in years

Wildlife officials have been logging hundreds of calls from Ventura to Orange counties reporting large numbers in deaths of birds and sick marine animals.

By Laura Tate / Associate Publisher/Editor

Dead birds by the dozens have been washing up and sick and disoriented sea lions have been found onshore on Malibu’s beaches in the past two weeks. More than 30 dead birds and several sick sea lions were photographed on Point Dume beaches on April 23, and dozens of dead birds were found on La Costa Beach this week.

Jonsie Ross, a volunteer with the California Wildlife Center’s Marine Mammal Response Team, said the organization, “has been working from sunrise to sunset rescuing sea lions that are hauling out on every beach up and down Malibu’s coastline…we can’t keep up with it, there are so many. “

“This is the worst it’s been in many years,” Ross said.

Wildlife and animal rescue officials are attributing the deaths and sick marine mammals to domoic acid poisoning, an occurrence that takes place when algal blooms increase in warmer ocean waters.

Advertisement

Reports of dead birds and sick marine mammals have also been coming in from Ventura to Orange County.

Although these incidents are not unusual, happening annually when the weather becomes warmer, the poisonings “came on early and strong,” said Tristen Joy, assistant marine mammal rescue coordinator at the California Wildlife Center.

In Malibu, a large number of cormorants have been found among the dead species of birds, along with grebes and loons, Joy said. She said some sick and dead pelicans have been collected as well, but not as many as last year.

“This is my third season here, and each one has been a little different,” Joy said. “In the past there have been some large die-offs [of other species of birds]; some years there are more sick sea lions, other years there are more sick or dead birds.”

Unable to officially explain why there were a large number of cormorants and grebes among the dead, Joy said that this past winter a large number of those types of birds had been found extremely emaciated. The theory is, she said, that because of El Niño-type weather producing warmer waters during the winter, the fish those birds feed on moved north to colder water, leaving the birds starving and in a weakened condition, and unable to withstand the domoic acid’s effect.

An official with the International Bird Rescue and Research Center in San Pedro reported that they have received hundreds of calls about the dead birds. Cristina Verduzco, a wildlife rehabilitator volunteer coordinator with IBRRC, said there is no official count of dead birds because many had been picked up by animal control officers before wildlife officials learned about the problem.

Contrary to the findings in Malibu, Verduzco said that most birds reported dead or sick have been pelicans, with some loons, grebes and cormorants among the dead, which she said they normally don’t see.

She said that pelicans probably sicken easier because they fish in deeper waters on large schools of anchovies and sardines, which are the fish most likely to be carrying larger amounts of the toxins.

Domoic acid is a neurotoxin produced by microscopic phytoplankton called Pseudonitzschia, according to the California Wildlife Center. Found in California’s oceans when a large bloom of the phytoplankton occurs, the amount of the neurotoxin increases in sardines and anchovies, which feed on Pseudonitzschia. Because of their simpler nervous system, the fish are not affected by domoic acid, but as the poison is transferred up the food chain and accumulates in larger marine mammals, the toxicity can cause disorientation, lethargy, loss of muscle control, seizures and death. Humans can be poisoned if they consume shellfish that has fed on the phytoplankton.

Officials recommend that people stay away from any wildlife, dead or alive, they may encounter.

Ross of the Marine Mammal Rescue Team wrote: “We are having problems with people interfering and harassing these already very sick animals; poking them with sticks, trying to pet them, etc. They are protected by the Marine Mammal Protection Act, which is a federal law … there is a $10,000 fine for harassing them or coming within 100 feet of them. People don’t realize that they [the sea lions] will bite and the poisoning affects their brains and can make them very aggressive if disturbed. We don’t want them to get hurt and we don’t want the public to get hurt.”

Tom Ford, associate director of the environmental organization Santa Monica Baykeeper, said he believes the problem of increasing algal blooms and the resulting poisonings is growing worse every year. He attributes part of the problem to pollution of ocean waters from runoff containing nutrients from fertilizers and agricultural agents.

13StarsManager
13StarsManagerhttps://malibutimes.com
The Malibu Times is the first newspaper in Malibu, serving the community since 1946.

Related Articles

Advertisement

Advertisement

Advertisement
Advertisement
Advertisement

Advertisement

Latest Articles

Advertisement

%d bloggers like this:
×