It’s long been known that sharks help nourish coral reefs, but exactly to what extent has never been scientifically mapped out — until now.
A pioneering study — led by scientists from Imperial College London in collaboration with marine biologists from UC Santa Barbara — found that the predators, through their fecal material, transfer vital nutrients from their open ocean feeding grounds into shallower reef environments, contributing to the overall health of these fragile ecosystems. The researchers specifically examined the role of grey reef sharks (Carcharhinus amblyrhynchos), a predatory species commonly associated with coral environments but whose wider ecological role has long been debated. The international team’s findings appear in the journal Procedings of the Royal Society B.
“Our study shows that large mobile predators such as sharks may be a very important source of nutrients for even the smallest reef creatures, such as corals,” said co-author Jennifer Caselle, a research biologist at UCSB’s Marine Science Institute. “The role of sharks as top predators is well understood, but their role as nutrient vectors is far less studied.”
Working in the waters surrounding Palmyra Atoll — a national wildlife refuge managed by the U.S. Fish and Wildlife Service and situated 1,000 miles south of Hawaii — the scientists used acoustic tags to map the sharks’ movements across the atoll. They combined these insights with existing knowledge about the sharks’ feeding habits in open ocean (pelagic) environments where they consume much of their prey.
Read more at University of California - Santa Barbara
Image: This is Darcy Bradley and Jenn Caselle. (Credit: Sonia Fernandez)