The Smell of the Reef

Phytoplankton and algae living on coral reefs release a chemical which attracts fish from miles around, and could play a key role in reef ecology.

Ecosystems are all about balance, and the phytoplankton have an ingenious way to keep things in check.  Phytoplankton are similar to plants, they harvest energy from sunlight using chlorophyll, and are a vital part of the ocean ecosystem.  Zooplankton also play a vital role, including feeding on the phytoplankton.  Jennifer DeBose and colleagues at the University of California at Davis have shown that in response to being grazed by zooplankton, phytoplankton release a chemical, Dimethylsulfoniopropionate (DMSP), which attracts fish which feed on zooplankton.

DeBose and team tested the hypothesis at different reefs by releasing either DMSP or distilled water from special tanks and found over four times as many fish attracted to the DMSP plumes.

Their findings suggest that planktivorous fish, those that eat plankton, have developed a way to 'eavesdrop' on the interactions between phyto- and zooplankton to help find good food resources.