Numerous reports of ill sea lions found along the Central Coast of California

Scores of reports of sick sea lions along California’s Central Coast have wildlife rescuers on high alert. The culprit behind this increase in diseased sea lions? Domoic acid, a neurotoxin produced by harmful algal blooms.

The toxin accumulates in filter-feeding fish like sardines and anchovies, which are primary food sources for sea lions, dolphins, and fur seals. Giancarlo Rulli, a spokesperson for the Marine Mammal Center in Sausalito, reported that since mid-July, there has been a surge in affected sea lions along the coast in Santa Barbara and San Luis Obispo counties. Rescuers have responded to more than 70 sea lions, as well as two dolphins and two fur seals.

Tragically, approximately 25% of the sea lions did not survive, whether from the disease itself or humane euthanasia. The dolphins and fur seals also succumbed to the effects of the toxin. Rulli described the heartbreaking race against time when reaching the dolphins, noting that once they are out of water, their organs can be crushed by their own weight.

The Channel Islands Marine & Wildlife Institute has also received numerous calls regarding sick animals. Samuel Dover, the president of the wildlife rescue organization, shared that reports of sick sea lions were coming in at a rate of about 100 per day in Ventura and Santa Barbara counties. Despite their efforts, many of the animals did not survive.

Domoic acid targets the brain and heart, leading to seizures and heart failure. If left untreated, the toxin can cause permanent brain damage. Signs of domoic acid poisoning in affected animals can vary from lethargy to disorientation and classic head weaving.

This year’s algal bloom event seems to be predominantly affecting adult female sea lions, according to Dover. In past events, the poisoning did not show a preference for sex or age. The outbreak in 2023 lasted for 27 days, shorter than the 37-day outbreak in 2022.

Rescuing these large marine animals can be challenging due to their size. An adult female sea lion can weigh up to 250 pounds, while an adult male can reach up to 1,000 pounds. Resources are strained as it takes several people to rescue one adult female.

Both Rulli and Dover emphasize the importance of giving sick animals on the beach plenty of space and caution beachgoers to stay at least 50 yards away from seals and sea lions, whether they appear healthy or not. The National Oceanic and Atmospheric Administration urges the public to contact nearby wildlife rehabilitation experts if they come across marine animals they believe may be sick.

In the face of this crisis affecting California’s marine life, it is essential for the community to come together to support the efforts of wildlife rescuers and rehabilitation centers. By raising awareness and following guidelines to protect marine animals, we can work towards ensuring the health and well-being of these precious creatures.