A 3 Way Partnership at the Bottom of the Sea
by Sara CP Williams
In dense fields of seagrass that carpet coastal waters around the world, there’s a three-way interaction keeping the ecosystem thriving. Two-shelled mollusks, bivalves, bacteria inhabiting the bivalves’ gills, and seagrasses themselves all live symbiotically, new research reveals. The finding helps explain the long-standing puzzle of how seagrasses can survive in murky shoreline waters and offers insight into how scientists can better restore seagrass ecosystems, which are declining worldwide.
“I think it’s a really exciting and interesting idea,” says ecologist Jay Stachowicz of the University of California, Davis, who was not involved in the new study. “This is a type of interaction that people really hadn’t considered before as being critical to seagrasses.”
Often called marine nurseries, seagrass meadows harbor juvenile fish that spend their adult lives in coral reefs. Because of their shoreline locations and lush grasses, the meadows have dense layers of sediment and decaying organic material, a rich feeding ground for most ocean life. But the muddy deposits present a conundrum for the seagrasses: the bacteria responsible for breaking down the decaying matter emit high levels of sulfide, which should be toxic to the plants…
(read more: Science NOW) (image: Marjolijn J.A. Christianen)