Tracing the otters’ demise

When seizures wracked sea otters washing up at Morro Bay and Pismo Beach this spring, muscle tremors and comas suggested that a red tide had caused domoic acid poisoning.

But a brain parasite associated with possum feces is the culprit, state veterinarians said last month. The bug infected at least half of the 22 dead otters. It may contaminate shellfish eaten by otters.

The killer, Sarcocystis neurona, a single-cell parasite found in possum excrement, claims a few otters each year but not so many at once, according to state veterinarian Melissa Miller.

Otters, once hunted to the brink of extinction, now number about 2,825 along the California coast.

-- Ashley Powers