Thank you for signing up to our email!

Now, before you leave, do you want to make a seal's day?

Sea Lions and Heart Disease

A growing number of California sea lions rescued by The Marine Mammal Center with acute or chronic domoic acid toxicity also have heart problems. By implanting EKG loop recorders into sea lion patients, the Center's researchers will gain a better understanding of the relationship between these two health issues.

Veterinarians from The Marine Mammal Center prepare to sedate "BBQ", a California sea lion patient, before she receives an EKG loop recorder.
© Stan Jensen



"Chance" and "BBQ" are just two of about 28 California sea lions admitted to The Marine Mammal Center between January and July 2010 suffering from a neurotoxin that affects their brains, and in many cases, can be fatal. This neurotoxin is known as domoic acid toxicity and is produced by several types of marine algae that eventually enter into the marine food chain. 

Chance and BBQ have consumed enough domoic acid to have caused permanent damage to their brains which could result in debilitating seizures or heart attacks if they were out in the wild. While the prognosis for these animals is not good, researchers at the Center are using the opportunity to study the relationship between the neurotoxin and heart lesions while these patients are under medical care.  Researchers implanted EKG (electrocardiography) loop recorders into each sea lion, in order to detect rhythm disturbances in the heart that could be fatal. This information is valuable and can help prevent the suffering of countless other animals that are rescued and exhibiting signs of acute or chronic domoic acid toxicity. 

Dr. Vanessa Fravel of The Marine Mammal Center places a small EKG loop recorder into a California sea lion patient suffering from domoic acid toxicity.
© Stan Jensen

The life threatening aspects of this disease are the sequel to uncontrolled seizures; hyperthermia if a sea lion is on a beach in the hot sun, aspiration and drowning, or secondary pneumonia. It may be hard to know that these animals might die, but, it is comforting to know that they will not get turned loose to suffer at sea and that the tremendous knowledge gained from them will help researchers continue to investigate a better understanding of this uniquely aquatic toxin that is itself a potential marker of ocean health.

Click here to read a science paper about this topic co-authored by The Marine Mammal Center. 

Chance rests in her pen after her EKG loop recorder surgery.
© The Marine Mammal Center


Who are Chance and BBQ?

BBQ is a female California sea lion that was rescued on June 25, 2010 at New Brighton Beach in Santa Cruz County. She was thin and lethargic. When rescuers from the Center arrived, they saw that good-intentioned people were pouring water on her. At the Center, veterinarians diagnosed her with chronic domoic acid toxicity. Learn what to do when you come across a marine mammal that appears to be ill or injured by click here.

Chance is a female California sea lion that was rescued on July 8, 2010 at Oceano Dunes in San Luis Obispo County. She too was thin and lethargic and didn't react when approached by people on the beach.  Her working diagnosis is acute domoic acid toxicity. 

Printer Friendly


COVID Response

Focusing on safety in our core work.

Adopt a Seal

Your symbolic adoption helps our patients thrive.

Our Commitment

Expanding work on social and environmental equity.