(Gaviota) Along the California coast, Denise Christ is used to seeing injured or stranded marine mammals. But the unprecedented number of sea lions and dolphins found dead intoxicated in recent weeks is of great concern to this volunteer.
“It’s heartbreaking, to say the least,” laments this stranding coordinator from Ventura County, in southern California (western United States), who gives her free time at the Channel Islands Marine Life Institute (CIMWI).
Animal poisoning is due to domoic acid which acts as a neurotoxin. It is present in the algae on which fish feed, which in turn serve as food for sea lions (also called sea lions), and dolphins.
Epidemic foci of this type are not unusual in summer, but two successive crises less than a year apart led the CIMWI team, based in Gaviota, about 190 kilometers north of Los Angeles, to draw the alarm bell.
“We had a very intense outbreak last year, but this year has been much worse than anything I’ve seen in 35 years in the business,” Sam Dover, executive director and co-founder of the company, told AFP. ‘institute.
“I was amazed by the number of animals that were on the beach, about 300 sea lions,” adds Ken Hughes, who works for Santa Barbara County. ” It’s very sad “.
“New Reality”
Scientists do not really explain this new epidemic this year but advance several theories.
“The seaweed generally comes from areas where there is agricultural waste,” notes Sam Dover. “This year, we have had a lot of rain in California, which means that agricultural waste is more numerous and comes from all over the state and not just from local areas. »
Ken Hughes, for his part, points out that the proliferation of algae is increasing in relation to rising temperatures and climate change.
“Things change, the ocean changes,” adds Denise Christ. “That’s the new reality.”
When sea lions consume this contaminated seaweed, it causes neurological damage and makes their behavior erratic, even aggressive.
“Basically, they no longer know they are sea lions. They no longer know where they are or what they are doing,” explains Ken Hughes.
According to Sam Dover, in 2022 the domoic acid outbreak started around mid-August.
But this year, the institute began receiving reports of affected animals as early as late May.
“Usually we treat one animal a day,” he says. “But on June 8, we started to see them appear everywhere. This is clearly the worst outbreak I have seen.”
Another particularity: the contamination now affects dolphins, for whom domoic acid is often fatal.
The institute has thus recorded at least 110 dolphins who have died of poisoning in recent weeks within its surveillance perimeter.
Since there is no cure or antidote, the only way to treat these animals is to give them fluids, food, medication to stop seizures, and patience, experts say.
For the centre’s volunteers, in addition to the emotional impact linked to all these deaths, the challenge is also logistical to pay for the medicines, feed and relocate these predatory animals.
Especially since the institute depends mainly on government aid, donations and voluntary work.
“Every day is a battle for the animals and for our finances,” says Sam Dover.