ScienceDaily reports on Steneck’s study about reef disappearance in Alaskan kelp forests

ScienceDaily reported on a study co-authored by Robert Steneck, a professor of oceanography, marine biology and marine policy at the University of Maine, about the effects of predator loss and climate change on the devastation of living reefs in Alaskan kelp forests. According to the report, the red alga Clathromorphum nereostratum built the limestone reefs, located in kelp forests in the Aleutian Islands, but sea urchins have been consuming them at an alarming rate. The functional extinction of the sea urchin’s predator, the Aleutian sea otter, in the 1990s allowed the marine invertebrate to explode in population, devour the kelp forests and threaten the reefs built by algae. Rising global temperatures have made it easier for sea urchins to pierce through the red alga’s protective layer and eat it. “Ocean warming and acidification are making it difficult for calcifying organisms to produce their shells, or in this case, the alga’s protective skeleton,” said Douglas Rasher, a senior research scientist at Bigelow Laboratory for Ocean Sciences and the lead author of the study. “This critical species has now become highly vulnerable to urchin grazing — right as urchin abundance is peaking. It’s a devastating combination.” The study was published in the journal Science.