Southern sea otter Yankee Doodle, wraps himself in simulated kelp strands while in rehabilitation at The Marine Mammal Center in Sausalito (TMMC), CA. The Center serves as the primary first responder for stranded sea otters across its 600-mile rescue range and recently retrofitted several existing pens at its Sausalito hospital to make them a suitable and safe space for the threatened species
Yankee Doodle, an adult male, feeds on shrimp during rehabilitation at TMMC. Sea otters must eat about a quarter of their body weight in seafood everyday just to maintain a healthy weight, and their specialized diet includes human-grade seafood such as scallops, clams, squid and shrimp
Volunteers Sue Hawley (L) and Stan Jensen (R) of TMMC release Yankee Doodle back to his ocean home at Pillar Point Harbor Beach in Half Moon Bay, CA, on Tuesday, October 24
Yankee Doodle makes his way to the water’s edge during his release at Pillar Point Harbor Beach in Half Moon Bay. As of May 2016, the southern sea otter’s range extends from south of Half Moon Bay in the north to southeast of Point Conception in the south—only a small part of their historical range
The lead item in yesterday’s NYTimes California Today column—The Plight of the Sea Otter—caught my eye for its mention of The Marine Mammal Center (TMMC), located here in the Marin Headlands. Several floating homes residents volunteer there on a regular basis. But what really grabbed my attention was the connection made between the vulnerability of the sea otters to a toxin called domoic acid and our own vulnerabilities.
Sea otters are considered to be keystone species—translation: they are fundamental (make or break) to the ecosystems in which they live. Algae blooms—naturally occurring, but increasing due to nutrient-rich fertilizer and waste runoff—are resulting in an alarming increase in harmful domoic acid, which appears toxic to sea otters. What does this mean for us, who eat the same things the sea otters eat?
Some stats from TMMC: as many as 20,000 southern sea otters may have lived along the coasts of California and Baja California at one time, but that is no longer the case. For the last 40 years, southern sea otters have been listed as threatened under the federal Endangered Species Act with the population estimated at just a few thousand.
Big Picture: land-sea pollution adversely affects marine life, and ultimately ourselves
Sea otters, once bountiful along the California coast, were virtually wiped out by fur traders in the 18th and 19th centuries.
A population estimated at as high as 20,000 fell to mere dozens.
Since coming under the protection of strict wildlife laws in 1977, the playful creatures have been rising in number, but with agonizing slowness.
In the last decade, the population of California sea otters — which range from just north of Santa Cruz down to the Santa Barbara area — has grown by an average of less than 2 percent a year, according to yearly census figures.
The most recent count in 2017 was 3,186, down 86 from a year before.
“It’s just been a real slow increase over time,” said Dr. Shawn Johnson, director of veterinary science at the Marine Mammal Center in Sausalito, a nonprofit that rehabilitates ailing marine life.
It doesn’t help that hundreds of sick and injured otters have been turning up dead or dying along the California coast.
In 2016, California wildlife officials recorded the highest ever number of stranded otters, 474. That’s up from 299 a decade earlier.
Many of the otters are mortally wounded by sharks. Some show evidence of disease, and others of poisoning linked to the algal blooms that have also been killing sea lions and menacing the state’s fishing industry.
The blooms occur naturally, but researchers believe they are being intensified by runoff that pushes waste and fertilizer into the Pacific. They release a toxin called domoic acid that winds its way through the marine life food chain.
Melissa Miller, a Department of Fish and Wildlife veterinarian who has overseen hundreds of otter necropsies, said more research was needed to fully understand how domoic acid was harming the otter population.
But she added, “I think we can safely say domoic acid is a big deal in otters. The hard part is how big of a deal.”
Otters are regarded as a keystone species, which means they are essential components of their ecosystem.
That they’re struggling should sound alarm bells not only about potential harms to marine life, but to humans as well, wildlife experts say.
“I see them as sort of a proxy for the bigger issue of land-sea pollution,” said Dr. Miller.
And don’t forget, she added, “We eat a lot of the same things that otters eat. And we clearly see that some of the things that otters are getting are associated with the food that they’re eating.”
