When climate change bites (literally)

Dane Blair, 14, was taking a swim on the beach in Del Mar, California, when a sea lion suddenly approached him.

Oliver Thansan
Oliver Thansan
15 July 2023 Saturday 04:26
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When climate change bites (literally)

Dane Blair, 14, was taking a swim on the beach in Del Mar, California, when a sea lion suddenly approached him. The appearance of the animal in that area was not too rare. Marine mammals of this species are frequent visitors, many of them residents, to the San Diego coast. What did surprise the boy were the two bites the animal gave him, one on the knee and the other on the rear. The wounds weren't deep enough to require stitches, but deep enough to make Dane bleed... And for him and his family to get a scare that will prevent them from forgetting July 4, 2023, the day of the event and the national holiday of the United States, which they ended up celebrating among journalists and television cameras attracted by the event.

The lion, the boy later recounted, appeared about thirty feet from where he was bathing and, as soon as he saw him, he submerged and seemed to disappear. But not. “Next thing I know, I felt a big bite on my leg,” Blair told NBC San Diego as he pointed to his right knee. The specimen then bit him hard on the rear and no longer wanted to let go. The boy only managed to get rid of his attacker when he reached the shore and returned to his family.

The animal stayed there, stranded on the sand. He did not show signs of aggression but of being sick. “He seemed tired. He had his eyes closed and his mouth was shaking,” Dane recalled. His father nodded: "Clearly, he was not well."

The media had been reporting similar incidents experienced by other bathers, surfers and divers for a few days, adding up to more than two dozen cases, all in the California counties of San Diego, Orange Santa Barbara and Ventura. The scientists attributed the bites to intoxication and neuronal involvement of the lions due to contamination with domoic acid, a neurotoxin produced by marine algae of the genus Pseudo-nitzschia.

Ingested by fish and zooplankton that are part of the sea lions' food chain, these harmful algae are proliferating with climate change and warming oceans. And this year they have invaded the Californian coast in a way and to an extent that biologists and specialists in the area did not remember.

Unbeknownst to Dane Blair and his father, environmental institutes had been warning bathers of the risk of coming into contact with marine mammals that might be sick from ingesting harmful algae. On June 24, the experienced swimmer and environmentalist Angela Lee, director of the NGO One With The Ocean, had suffered a sea lion attack in the waters of Santa Monica that left her with numerous injuries, especially on her arm. The story was published on July 3. And specialized centers such as the one for Pacific Marine Mammals had a "hospital alert for the influx of patients (veterinarians) affected by domoic acid" posted on their website – and yesterday they continued to have it – with the advice to stay away from these animals, the petition not to push those who were on the shore back into the sea and the indication of a telephone to report new cases.

Despite the alarm created by the bites to bathers and swimmers here and there, we must not lose sight of the fact that sea lions and the rest of the mammals in these and other waters are the main victims of large blooms of dangerous algae. Between June and the first week of July, more than 500 lions and 100 dolphins were found dead and as many sick on Californian beaches.

There is no antidote for domoic acid poisoning. Veterinarians can only treat affected animals with anti-seizure drugs and solutions to keep them hydrated, while waiting for their bodies to eliminate the toxins. It's a fight against time: the longer the poison stays in the body, the more difficult it is to recover.

The causes of the massive proliferations or blooms of toxic algae that upset and kill these animals continues to be studied. “Blooms occur when colonies of algae (organisms that live in the sea and in freshwater) grow out of control, producing toxic or harmful effects on marine mammals, fish, shellfish, birds, and sometimes sea creatures. people. The human diseases caused by this phenomenon, although rare, can be debilitating or even fatal”, they explain in the National Oceanic and Atmospheric Administration.

Scientists agree that while algal blooms are a natural phenomenon, climate change and human activities affect their frequency and intensity. And that incidence seems to be increasing.

The director of the Channel Islands Marine

The California Marine Mammal Center diagnosed the first case of domoic acid poisoning in these animals in 1998. Outbreaks were then recorded in the years 2002, 2006, 2007, 2017 and 2022, which until now had been the worst. But last summer the invasion lasted six weeks and the victims numbered a few hundred, while now there are more than a thousand in almost nine weeks, although the crisis tends to subside. Until next summer?

“We know that algae thrive in unusually warm waters off the west coast; ocean conditions that have become more frequent in recent years, as the impacts of climate change have increased," they point out at the Marine Mammal Center.

"These species are sentinels of the health of the oceans and alert us to potentially dangerous environmental changes in the ocean," Samuel Dover and his Cimwi team explain on the organization's website. If this is so, and if we take into account that the planet depends absolutely on the oceans, what does it mean that hundreds of sea lions and dolphins die year after year, each time in greater numbers, on the shores of one of the populations Most important in the world? And even knowing that their attacks are the result of a neural disorder, how should we take it when some of these animals attack people before succumbing? Isn't this, after all, one more touch of Mother Nature? Warned we are.