Sea otters, the fuzzy mascots of the California coast, have fought back over the past 75 years from near-extinction. From the 1970s to the 1990s, their numbers steadily grew. But recently, their population growth has stalled. Scientists aren’t sure why, but they are alarmed. One key suspect: house cats.
In a study published in 2002, UC-Santa Cruz researchers reported that 62 percent of 107 dead sea otters collected along the California coastline from Half Moon Bay to Santa Barbara were infected with Toxoplasma gondii, a parasite found in cat waste. Biologists say they think otters are being exposed to the parasites from yards and litter boxes — whether the waste is flushed indoors or washed from outdoor areas into storm drains and streams.
Although they haven’t made a definitive connection – toxic chemicals in boat paint, blooms of harmful red tides and other theories also abound; scientists and environmental groups convinced Sacramento lawmakers in 2006 to pass a bill offering new protections to otters while the research continues. Signed by Gov. Arnold Schwarzenegger in September, the measure requires all cat litter sold in California starting Jan. 1, 2007 to have a warning label telling people not to flush it down the toilet. The bill also creates a new check-off box for donations on state tax forms to fund more sea otter research into parasites and diseases, and it doubles penalties for harming otters to $25,000. Quest follows the researchers, and sits in on an otter autopsy as scientists try to unlock the mystery.