California’s Marine Lions: Seaweed’s Aggressive Impact
- LOS ANGELES (AP) — Unusually aggressive behavior by sea lions,including two recent attacks on swimmers in California,might potentially be linked to a toxic algae bloom,experts say.
- the suspected culprit is Pseudo-nitzschia australis, a type of algae that produces domoic acid, a potent neurotoxin.
- Warmer ocean temperatures,exacerbated by climate change,create favorable conditions for the algae to thrive.
Toxic Algae Bloom Suspected in California Sea Lion Attacks
LOS ANGELES (AP) — Unusually aggressive behavior by sea lions,including two recent attacks on swimmers in California,might potentially be linked to a toxic algae bloom,experts say. The incidents,while rare,have raised concerns about the health of marine life and potential risks to humans.
Harmful Algae Bloom Linked to Domoic Acid
the suspected culprit is Pseudo-nitzschia australis, a type of algae that produces domoic acid, a potent neurotoxin. According to researchers, this neurotoxin can disrupt the nervous systems of various animals, including marine mammals, birds, and even humans.
Warmer ocean temperatures,exacerbated by climate change,create favorable conditions for the algae to thrive. Experts have noted an increase in the frequency and intensity of these blooms along the California coast over the past decade.
how Domoic Acid Affects Sea Lions
Sea lions don’t directly consume the algae. Rather, they ingest the toxin by eating contaminated fish, such as sardines and anchovies, which feed on the algae. While low levels of domoic acid are typically manageable for sea lions, high concentrations can lead to domoic acid toxicosis.
The Channel Islands Marine & Wildlife institute reports dealing with as many as 150 cases of sea lion intoxication daily.According to the Marine Mammal Center, sea lions suffering from domoic acid toxicosis exhibit a range of symptoms, including head swaying, seizures, lethargy, and perhaps fatal heart problems. Survival rates for treated sea lions range from 55% to 65%. Common dolphins are almost always fatally affected.
Attacks on Swimmers
While no recent cases of human poisoning have been reported, two incidents involving sea lion attacks on swimmers have occurred. rj Lamandola, a 40-year-old surfer, was bitten on the back and described the animal as having a ”ferine” and “possessed” appearance. Phoebe Beltran, a 15-year-old girl taking a lifeguard exam, was briefly hospitalized after being bitten on the arm.Beltran initially feared a shark attack.
Experts suggest that even low-level exposure to domoic acid can cause exaggerated reactions to external stimuli, potentially contributing to the aggressive behavior observed in the recent attacks.
Human Health Concerns
Humans can be affected by consuming contaminated seafood. Domoic acid intoxication in humans can damage the amygdala, a part of the brain, leading to short-term memory problems, a condition known as “amnesic shellfish poisoning.”
Toxic Algae Bloom and Sea Lion Attacks: A Q&A
What’s causing the unusual sea lion behavior and attacks?
Experts suspect a toxic algae bloom is linked to the unusual aggression of sea lions, including recent attacks on swimmers in California.
what type of algae is responsible for the toxicity?
The suspected culprit is *Pseudo-nitzschia australis*, a type of algae that produces domoic acid, a potent neurotoxin.
How does domoic acid affect sea lions?
Sea lions ingest domoic acid by consuming contaminated fish, such as sardines and anchovies, that feed on the algae. High concentrations of the toxin can lead to domoic acid toxicosis.
What are the symptoms of domoic acid toxicosis in sea lions?
Sea lions with domoic acid toxicosis can exhibit several symptoms, including:
- Head swaying
- Seizures
- Lethargy
- Potential heart problems
What is the survival rate for sea lions with domoic acid toxicosis?
Survival rates for treated sea lions range from 55% to 65%. Common dolphins are almost always fatally affected.
Have there been any recent human poisonings?
No recent cases of human poisoning have been reported.
Have there been any sea lion attacks on humans?
Yes,two incidents involving sea lion attacks on swimmers have occurred recently.
What are the potential effects of domoic acid on human health?
Humans can be affected by consuming contaminated seafood. Domoic acid intoxication in humans can damage the amygdala, perhaps leading to short-term memory problems, known as “amnesic shellfish poisoning.”
How is climate change related to the algae blooms?
Warmer ocean temperatures, exacerbated by climate change, create favorable conditions for the algae to thrive. There has been an increase in the frequency and intensity of these blooms along the California coast over the past decade.
What does the Channel Islands Marine & Wildlife Institute report regarding sea lion intoxication?
The Channel Islands Marine & Wildlife institute reports dealing with as many as 150 cases of sea lion intoxication daily.
Summary Table
Here’s a summary of the key facts:
| Topic | Details |
|---|---|
| Suspected Cause of Aggression | Toxic algae bloom producing domoic acid |
| Algae Type | Pseudo-nitzschia australis |
| How Sea Lions are Affected | Ingest toxin thru contaminated fish |
| Sea Lion Symptoms | Head swaying,seizures,lethargy,possible heart problems |
| Sea Lion Survival Rate | 55% to 65% with treatment |
| Human Health Risk | Amnesic shellfish poisoning from contaminated seafood |