A Reason We “Otter” Give Thanks

A Reason We “Otter” Give Thanks

Who doesn’t enjoy watching sea otters at play? Whether frolicking freely in the waters near Monterey, CA, or entertaining aquarium visitors worldwide, otters fascinate and delight us with their antics. The smallest of aquatic mammals evoke some very big smiles.

As if the pure pleasure they bring isn’t enough of a gift to humanity, it turns out sea otters provide a significant service for humanity’s (and other creatures’) well-being. Researchers recently discovered that these agile “aquabats” serve as guardians of Earth’s kelp forests. In doing so, they protect the environment and contribute to human health, not to mention the economy.

Because sea otters are so active, they exhale a considerable quantity of carbon dioxide (a greenhouse gas), seemingly adding to our atmospheric temperature increase. However, a study led by UC Santa Cruz biologists shows that indirectly—by protecting kelp—otters take far more than they give, and that’s good.1 Their choice of food is the key.

Sea otters eat sea urchins—the spiny, prickly, purple things you may have seen in tide pools. If the urchins’ population were to grow unchecked, these voracious eaters would literally denude and devastate kelp, one of nature’s most prolific carbon consumers. In one region alone, between Vancouver Island and the westernmost Aleutian Islands, the otters’ consumption of urchins allows the kelp forests to remove 5 million tons of carbon per year.

Sea otters may prove all the more important as scientists continue to probe kelp’s potential as a significant source of both food and biofuels. Already kelp is prized as a source of dietary iodine and as an aid to human digestion. It holds promise for curbing obesity, as well.2It seems kelp farms, which require no irrigation and only minimal maintenance, represent a viable solution to multiple pressing problems. However, they do need a healthy supply of sea otters. So let’s take good care of these furry helpers, even as we give thanks for them on November 22.

  1. Christopher C. Wilmers et al., “Do Trophic Cascades Affect the Storage and Flux of Atmospheric Carbon? An Analysis of Sea Otters and Kelp Forests,” Frontiers in Ecology and the Environment (October 2012): 409–15.
  2. Lulu Sinclair, “Is Seaweed the Answer to a Dieter’s Prayer?” Sky News Online, posted March 22, 2010, https://news.sky.com/story/767265/is-seaweed-the-answer-to-a-dieters-prayer.