Smell of the sea leads fish to food, affects climate

March 7th, 2008 - 11:57 am ICT by admin  

Washington, March 7 (IANS) The ocean has an “odour” that affects global climate and also attracts reef fish to feed as they “eavesdrop” on events that might lead them to food. The odour, traced to DMSP (Di-methyl-sulfoniopropionate), is given off when either tiny animals in the plankton are feeding on the algae, or during an algal bloom, said Jennifer DeBose of the University of California at Davis who conducted a study on ocean odour.

Once released into the atmosphere, derivatives of DMSP promote cloud formation, which, by reflecting more sunlight back into space, cools the earth.

These sulphur compounds serve as odour signals to marine organisms and are likely to play an equally important role in marine ecology, said Gabrielle Nevitt, co-author of the study, according to a University of California press release.

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 in the 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.

“DMSP is the smell of a productive, healthy reef.”

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