Sea Otters to the Rescue

California’s kelp beds have been in an unprecedented state of collapse since 2013.  Losses are patchy from San Diego to Monterey, but north of the Golden Gate, more than 95% of the kelp is gone.

 In 2013 a marine heat wave, dubbed by scientists as “the blob” caused ocean temperatures to spike, weakening the kelp which thrives in cold currents.  Then in 2019, a virus, probably supercharged by warming waters, allowed purple urchins, voracious kelp eaters, to escalate.  The purple urchins are laying waste to California’s kelp beds.

SEA OTTERS are greedy consumers of the purple urchins.  Could this be the remedy?  Furry sea otters “run hot”:  their metabolism requires that they eat up to a quarter of their body weight each day in abalone, crab, octopus  -- and urchins.  It was a remnant population of sea otters from Big Sur that recolonized Monterey Bay.   They played a key role in restoring the area’s kelp forests after the closure of Monterey’s polluting canneries.

There are some blips, of course. Too far north and there are sharks. Also, once purple urchins destroy too much kelp, they turn auto-cannibalistic rather than starve to death; they feed on themselves. The urchin barrens are thus, in part, populated by “zombies.” Otters aren’t much interested in the shell-like results.

Kelp forests are good at reproducing themselves. One hope is that the balance the otters maintain would allow kelp to reseed whenever and wherever a storm or some other natural (or human) event, scrapes away enough zombies.

Letting otters expand their range would be ideal.  If we help relocate small teams of them (10 or 12), otters could help in the battle to save North Coast kelp. The way back to a healthy ocean will take planning, funding and cooperation. Reestablishing sea otters throughout their traditional range could be a start.

Photo Credit: Getty Images