Sea otters are good for kelp and good for us

Kelp is a keystone species. Underwater kelp forests provide habitat and hunting grounds for many species, including floating furballs known as sea otters, and are excellent at storing carbon.


A sea otter enjoying their time in a kelp forest

This week is Sea Otter Awareness Week and it’s meant to celebrate, well… sea otters.

These marine mammals are incredible critters and are absolutely vital in keeping our coastal ecosystems healthy here on the Pacific Coast. In particular, sea otters help foster kelp forests that are excellent at storing carbon and provide the habitat and hunting ground for countless sea creatures, including otters.

A forest beneath the waves

At a surface glance let’s face it, kelp is pretty unsightly. However, below the surf, towering kelp forests flow in the current and almost glisten in the sunlight. Kelp is an incredible plant that can stretch over 100 feet from the seafloor and grow over one foot a day in some cases. Within those towering strands is the perfect home for numerous kelp-loving critters like abalone, rockfish and Dungeness crab.

And because of how dense and tall these forests can get, they are also one of the most effective ecosystems at sequestering carbon from our atmosphere. In fact per acre, these underwater forests are able to sequester up to twenty times more carbon than terrestrial forests.

We know that addressing climate change requires storing carbon, and nature can do that.

We must support our forests, and ones made of kelp are certainly no exception. Sadly though, kelp forests in the Pacific are under attack from a plight of purple sea urchins, and some estimates suggest a 95% loss of kelp in some areas. Fortunately, our fuzzy floating friends may offer the perfect solution.

An otter’s favorite snack

Before being hunted to the brink of extinction, hundreds of thousands of otters inhabited coastal areas from Mexico to Alaska. Today, pockets of a few thousand live in California’s and Washington’s waters (southern sea otters and northern sea otters, respectively), where they feast on an overabundance of purple sea urchins, one of their favorite treats.

But without otters and if left unchecked, these spiny sea creatures will continue to threaten kelp all across our coast, which is why we need sea otters now more than ever.

Giving kelp a helping hand

Urchins are a favorite food, and otters chow down. They keep warm with a high metabolism. An otter eats about a quarter of its body weight each day. Think of it this way — this is the equivalent of a 150 pound human eating 37.5 pounds of food in one day.

By feasting on urchins throughout the year, otters mitigate the impacts urchins have on kelp forests. We know without them, kelp disappears, which would prove disastrous for our climate and for all the rockfish, abalone and Dungeness crab that call these underwater forests home.

What ‘otter’ we do about it?

It’s clear otters are critical for healthy kelp forests that are essential for our coastal ecosystems and a livable climate. The more that we can do to protect and restore their historic range the better.

That’s why we advocated that federal protections for southern sea otters remain in place. Thank you to the U.S. Fish and Wildlife Service for keeping them in place. And we support reintroducing otters to habitats where they once thrived.


Ian Giancarlo

Protect Our Oceans Campaign, Advocate, Environment America

Ian works to protect our oceans and marine ecosystems. Ian lives in Denver, where he enjoys triathlons, hiking, and local breweries in his free time.

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