Loss of Aleutian Sea Otters and Climate Change to Devastate Coral-like Reefs, Study Suggests

Jan, 2021 - By SMI

According to a new research study by the researchers of Bigelow Laboratory for Ocean Sciences have reported that loss of sea otters and climate change are adversely impacting the living reefs, an important part of Alaskan kelp forests from centuries.

Douglas Rasher, lead author of the study stated, “We discovered that massive limestone reefs built by algae underpin the Aleutian Islands' kelp forest ecosystem. However, these long-lived reefs are now disappearing before our eyes, and we're looking at a collapse likely on the order of decades rather than centuries.”

Moreover, researchers suggested that coral-like reefs that are built by Clathromorphum nereostratum (red alga), are diminished by sea urchins. This is due to increasing number of sea urchins, owing to extinct of Aleutian sea otter, which are natural predator of these sea urchins. Rising number of sea urchins have destroyed dense kelp forests, and now focusing on coralline algae that form the reef.

Clathromorphum produces a limestone skeleton that protects the organism from grazers and creates a complex reef that supports rich diversity of marine life. However, sea urchins are now entering the alga's tough protective layer to eat the alga, which has become easier for urchins due to climate change. Researchers also informed that climate change that has resulted in ocean warming and acidification are hindering the process of calcifying by organisms to generate their shells, or in this scenario, the alga's protective skeleton and have become highly susceptible to urchin grazing.

Researchers reported that the discovery of this association between predators and climate change are expected to offer several ways to tackle the reef destruction. Moreover, reducing greenhouse gases is the urgent need and reinstating sea otters is equally important, as it has the ability to alleviate reef erosion by urchins, and enhance the marine ecosystem.