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Sea otters are a lifeline for reefs in a changing ocean

With their round, furry faces and tendency to hold hands while they sleep, sea otters seem almost perfectly built to appeal to our sense of the adorable. But they also play a vital role in protecting their ecosystem from the effects of climate change.

Sea otters are what scientists refer to as a keystone species—their presence keeps an entire ecosystem in balance. In a recent paper, Justin Ries, a professor of marine and environmental sciences at Northeastern, and his colleagues demonstrated how keystone predators like sea otters can help mitigate the effects of climate change and give an ecosystem a fighting chance.

“It’s really an example of the importance of ecosystem stability when climate change is occurring,” Ries says. “If the ecosystem is healthy, the system can withstand more climate change stress than when the system is out of balance for ecological reasons, like the top predators removed.”

The researchers focused on the frigid waters around the Aleutian Islands, which curl off the southwestern tip of Alaska. Here, forests of looming kelp fronds provide homes and habitats for a bevy of marine life, including sea otters and their favorite prey—sea urchins.  

Sea urchins are grazers. They have five sharp teeth that come together on the bottom of their body to grind down and devour whatever they climb on top of, including the stems of kelp. Sea otters protect kelp forests by chowing down on the urchin population.

“In the system without the otters, there could be 100 urchins in a 10 foot by 10 foot square space,” Ries says. “The kelp are gone, and it just looks like a desert.” 

Read more at Northeastern Global News.

AP Photo by Jacob King/PA Wire

Author: Laura Castañón