
Hakai Magazine: How Terrestrial Turds Lead to Marine Maladies
- Parasites
- Pathology
- Toxoplasmosis
Diseases from land animals are killing marine mammals at an alarming rate.
Published in Hakai Magazine: January 2, 2024
For marine mammals, changes in ocean temperature and chemistry caused by a warming climate and pollution may be contributing to immunosuppression. Dr. Cara Field, Medical Director at The Marine Mammal Center explains that this could be making animals more susceptible to sarcocystosis and other diseases.
“These contaminants and pollutants often affect our immune systems,” she says. “We know that when an animal’s immune system is compromised, they are more susceptible to disease and severe parasitic infections, which is very concerning.”
Even as the Center’s network of first responders grows and care improves as the world’s largest marine mammal hospital, marine mammals will continue dying from these diseases, says Field. And that is because of the diffuse, complex, and global nature of the problem: namely our land-devouring, planet-altering industrial society.
She adds, “The more that we change and exploit our natural environment…the more we remove those natural barriers that nature has established over eons to help filter out things like these protozoal pathogens.”
Meet the Featured Patient
Decker the California sea lion had been diagnosed with sarcocystis. After four months of treatment and recovery at the Center, he was released back to the wild at Point Reyes National Seashore.
Read more about Decker

Disease Research at The Marine Mammal Center
As the world’s largest marine mammal hospital, the Center learns from the hundreds of animals we rescue each year to help us all better understand the health of the ocean environment.
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Predicting Prognosis in Wildlife Rehabilitation: A Case Study of Leptospirosis in Sea Lions
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Treating California Sea Lions with Sarcocystis-Associated Multi-Phase Muscle Breakdown
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pathology
toxoplasmosis
Cara Field
Pádraig Duignan
California Sea Lion