California's sea otters were once hunted to the brink of extinction. We can thank conservation laws like the Endangered Species Act for there being a few thousand of them floating and paddling along the Central Coast today.
But their slow recovery faces a barrage of hazards fueled by climate change. These furry marine mammals are threatened by disease, sharks, harmful algae blooms, kelp forest loss, warming waters and ocean acidification. It's no wonder their population has dipped below 3,000 in recent years.
So it's a relief that they caught a break from the U.S. Fish and Wildlife Service, which last week rejected a fishing industry petition to kick the southern sea otter off the endangered species list. The California Sea Urchin Commission and Commercial Fishermen of Santa Barbara sought to strip protections on the grounds that otter numbers and their range have increased since they were listed as threatened in 1977. Sea otters' voracious appetite for sea urchins, clams and abalone has for decades put them in conflict with fishing interests.
The agency's finding against delisting was based on the animals' exposure to harmful pathogens, habitat loss and other threats that are being exacerbated by climate change and will "most likely reduce the ability of the species to sustain itself in the future."
It's right for wildlife officials to be cautious in decisions affecting keystone species like sea otters, salmon and Joshua trees, whose future is clouded by the changing climate. The vitality of the sea otter population tells us a lot about the health of the ocean food web they help sustain, especially because of their role in kelp forests and eelgrass estuaries. Otters prey on sea urchins that graze on giant kelp, keeping their populations in check and helping the kelp grow and provide more habitat for fish and other aquatic plants and animals. When otters are absent they can leave behind "urchin barrens" that are devoid of other sea life.
Southern sea otters' threatened status gives them special protections from being killed, captured, swept up in commercial fishing operations and other kinds of human interference. These important safeguards should remain in place until it can be demonstrated conclusively that sea otters have made a robust and sustained recovery. Proactive measures are also needed to help sea otters spread up the coast to reclaim more of their historical range to give them a better chance against the escalating effects of climate change.
Sea otters were once found across the North Pacific Rim from Mexico to Japan, with about 16,000 in waters from Oregon to Baja California. They were nearly wiped out by hunting for the fur trade in the 19th century. By the early 1900s, all that was left of the southern sea otter subspecies was a few dozen animals along the Big Sur coast.
Since they gained endangered species protections, southern sea otters have reclaimed about 13% of their historical range, spanning some 300 miles of California's Central Coast. But a 930-mile stretch of coastline from Northern California to Washington is devoid of otters, and their range has not expanded in more than 20 years because of fatal shark bites.