Avoiding otter chaos

Published December 10, 2012 in Oceans

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California’s sea otters eat sea urchins, holding their numbers in check. That helps keep kelp (a favorite urchin snack) abundant enough to provide food and shelter for fish and invertebrates. If the otter population falls too far, that could set in motion a chain reaction of species decline.

EDF, UC-Santa Barbara and NOAA recently began a collaboration to devise early warning indicators and management tools that will allow regulators to protect whole ecosystems by showing how key species like sea otters keep the ecosystems healthy and resilient. 

“It turns out that human activities like fishing and pollution can push ocean ecosystems past thresholds, causing them to degrade suddenly,” says EDF scientist Dr. Rod Fujita. 

The project could aid the roughly 2,800 sea otters living in California waters. The population, which once numbered some 15,000 before being decimated by the fur trade in the early 1900s, descends from a single surviving colony off Big Sur.

See more details on the project in the EDFish blog post Finding the Ecological Cliff and Staying Away from It: Thresholds for Sustainability.