A recent influx of California sea otters off the coast of Santa Barbara has raised questions about what impact the migrating animals will have on local marine ecosystems.

In addition to environmental concerns, fishermen fear the otters’ consumption of shellfish in the area will negatively affect the fishing industry. Two decades ago, state and federal officials attempted to address these concerns by establishing a U.S. Fish and Wildlife Service “no otter zone,” which attempted to establish an otter population on San Nicolas Island and relocate those who strayed. Most of those otters died, however, and others are now returning to the area.

Some environmentalists argue that the influx of otters could help bring balance to the ecosystem. Allison Ford, executive director of The Otter Project, a Monterey-based non-profit organization, said otters eat sea urchins, creatures that can cause kelp beds to diminish.

“It’s our belief that otters, as a keystone species — from a conservationist standpoint — will be greatly beneficial to the Santa Barbara area,” Ford said. “As otters move back into the system, you are likely to see an increase in bio-diversity.”

Ford also said the impact on shellfish will not be huge or immediate, and will likely take years to create a threat to local companies. 

“The environmental and economic benefits that come with the otters outweigh the bad,” Ford said. “Sea otters are like gardeners; they prune the pests.” 

The Otter Project published a report this month noting a decrease in the otter population. The animals are listed as a threatened species under federal law, and the Project’s study showed a 3.8 percent lower otter count from 2008, leaving a total of 2,654 otters in California.

According to Ford, the otters are dying in part because of weakened immune systems and in part because of the water quality.

UCSB Marine Science Institute scientist Milton Love said otters are ambitious animals and can dive about 300 feet under water in order to find food. Once their numbers grow in local waters, the otters will be forced to compete for resources, he said.

“Eventually there will be large numbers off the campus front, which will limit the number of food they can eat,” Love said. “They’ve been seen digging down three feet down in some mudflats up north. They dig down for clams a number of feet, and they will break [shellfish] shells apart using rocks.”

Like other ocean animals, otters are susceptible to oil exposure but, despite the rich oil deposits off Santa Barbara’s coast, Love said otters would not be heavily affected. He said Santa Barbara oil comes from natural deposits seeping up through the rock. Because the water is exposed to oil through natural processes, sea life is less affected.

In fact, Love said local oil rigs would probably serve as a source of food.

“Ironically, one of the major food of otters are muscles, and the platforms are likely to be a good food source for otters,” Love said.