Can't Live Without 'Em: Southern Sea Otters

July 21, 2011

A weekly homage to endangered species, large and small

SOUTHERN SEA OTTERS

The densest fur in the animal kingdom belongs to one of the nation’s most beloved creatures—the sea otter. The southern sea otter, also called the California sea otter, is as much a part of the Golden State’s pride as killer waves and surf-n-turf diners.

Sea otters grow on average up to 4 feet long. The smaller females weigh about 45 pounds, while males can reach more than 60 pounds. Because they don’t have blubber like seals or whales to insulate them against the Pacific Ocean’s cold waters, sea otters rely on thick fur for protection against the elements.

Other than primates, sea otters are one of the few animals to use tools. They use rocks and other items from their environment like hammers to break into molluscs and other prey. They are naturally gifted hunters, perfectly adapted to their environment. Typically sea otters hunt in shallow waters of less than 60 feet, but they can dive more than 300 feet to forage the ocean floor. Because of their high metabolism, sea otters eat as much as 25 percent of their body weight each day.

Despite their cunning, sea otters have remained on the list of endangered and threatened species since 1977. Originally, oil spills were considered the main threat to their survival. The sticky stuff mats their fur, diminishing its insulating abilities. And oily otters will eventually die from hypothermia or organ failure, and sometimes from swallowing oil when they try to groom themselves clean.

New findings, however, suggest there’s more foul play afoot. Since 1998, some 40-50 percent of sea otter deaths in California have been attributed to disease. While scientists say there’s no smoking gun exactly, the otter’s fondness for dining on filter feeders, like mussels and clams, could be partially to blame. These invertebrates tend to accumulate toxins from the water, and when otters eat them, the poisons get passed along.

All-purpose Otters

Trouble for the sea otters could mean big problems for near-shore ecosystems. Sea otters keep sea urchins and other invertebrates populations in check, so they don’t devastate underwater kelp forests (large seaweeds). Kelp forests act as critical buffers against storms and provide habitat for an array of marine life — from fish to seahorses. By locking up heat-trapping pollution like carbon dioxide, kelp forests also help in the fight against climate change.

Sea otters support life on-shore as well. As sea otter populations expand, economists predict otter-related tourism could provide up to 320 new jobs and an additional revenue of $1.5 million to $8.2 million over the next decade.

For cities like Monterey, California, the sea otter already provides huge economic boost. Evidence of the animal’s popularity is apparent throughout the Monterey Bay area, where otters adorns everything, from T-shirts and banners to mugs and posters.