Climate Change May Impact Predators to Influence Entire Ecosystems

Predators play crucial roles in ecosystems. They weed out prey that are sick or old, and they can even push species to move in order to stay in their climatic comfort zones. Now, scientists have taken a look at how climate change might impact predators which could, in turn, affect entire ecosystems.

As species adapt to a changing climate, there will be both "winners" and "losers." Some species will find themselves in better conditions and thrive, while others won't do nearly as well. In addition, how climate affects predator species could, in turn, impact the entire food web.

A historical example of this particular phenomenon is the sea otter. These mammals were once decimated by the fur trade that spanned the late 1700s to the early 1900s. This important predator species regulated prey in areas spanning from Alaska to Baja California, Mexico.

"The near extinction of sea otters is one of the most dramatic examples of human-induced impacts to the structure and functioning of temperate nearshore marine ecosystems," said Rebecca G. Martone, one of the researchers, in a news release.

Without sea otters, which live on abalone, clams, crabs, mussels, shrimp and sea urchins, kelp forests suffer. Without the otters, undersea urchins prey on kelp forests, causing dense areas to become barren and essentially disrupting entire ecosystems. In fact, scientists found that this may even have an effect on climate change.

Kelp forests grow rapidly and store large amounts of carbon. This means that if otters are absent and urchins are destroying these forests, more carbon is released. Not only that, but kelp provides a three-dimensional habitat for species such as rockfish, seals, sea lions, whales, gulls, terns, snowy egrets and some short birds. Without otters, though, these communities rapidly decline.

The analysis of the effect of sea otters shows that predators play huge roles in ecosystems. This means that climate change that affects predators negatively can also greatly impact ecosystems. A symposium focusing on climate's effects on predators will occur during the Ecological Society of America's 99^th Annual Meeting in Sacramento, California.