These sulfur compounds are also known to serve as odor signals to marine organisms and are likely to play an equally important role in marine ecology, said Gabrielle Nevitt, professor of neurobiology, physiology and behavior at UC Davis and senior author on the study. The researchers wanted to know if reef fish also respond to these chemicals.
DeBose released plumes of DMSP at low concentrations on reefs off the Caribbean island of Curacao, Netherlands Antilles.
"It was pretty impressive," she said. "We would be surrounded by hundreds of fish for up to 60 minutes." The plumes mostly attracted fish known to feed on plankton, such as brown chromis and Creole wrasse, and the researchers noted that these fish were mostly arriving from down-current as if they were following a plume of scent.
The fish are using scent to "listen" to the interaction between plant plankton and their predators, DeBose said.
"They’re not smelling food, but other cues that might lead them to food," she said.
DMSP is also given off by zooxanthellae, one-celled organisms that live inside coral polyps and allow them to photosynthesize. Stressed or damaged coral can lose its zooxanthellae and become "bleached," Nevitt said.
"DMSP is the smell of a productive, healthy reef," she said.
DMSP has mostly been studied in the context of atmospheric chemistry and global climate regulation, and not as a signaling molecule, Nevitt said. A better understanding of its effects could help in the recovery of damaged reefs, and understanding the links between climate change and the biological realm.
Sean Lema, Assistant Professor of Biology and Marine Biology, Center for Marine Science of the University of North Carolina in Wilmington, is also an author on the paper, published in the March 7 issue of the journal Science. The work was funded by the American Museum of Natural History and the Philanthropic Educational Organization.
Adapted from materials provided by University of California – Davis, via EurekAlert!, a service of AAAS.