Top predator species of the Southern Ocean, far-ranging seabirds, are tied to the health of the ecosystem and to global climate regulation through a mutual relationship with phytoplankton, according to a study from the University of California-Davis, published in Proceedings of the National Academy of Sciences.

When phytoplankton are eaten by grazing crustaceans called krill, they release a chemical signal that attracts krill-eating birds. The chemical signal, dimethyl sulfide (DMS), forms sulfur compounds in the atmosphere that also promote cloud formation and help cool the planet.

Seabirds consuming the krill then fertilize the phytoplankton with iron, which is scarce in oceans. “The data is really striking,” says Gabrielle Nevitt, Ph.D., a professor of neurobiology, physiology and behavior at the university, who co-authored the paper. “This suggests that top marine predators are important in climate regulation, although they are mostly left out of climate models. More attention should be focused on how ecological systems impact climate. Studying DMS as a signal molecule makes the connection.”

Source: Environmental News Network (enn.com)