Abstract
Plankton chemical ecology, the discipline investigating the role of ecological interactions that are influenced by chemicals, is a quite mature research field. Nevertheless, several conceptual problems arise if the function and evolution of chemical signalling in the sea is concerned. Modelling does not always allow prediction of an ecological role of metabolites, and bioassays that address entire plankton communities are rare. It is argued here that a comprehensive inventory of plankton signals and large scale bioassays addressing the role of selected metabolites in whole plankton communities might lead to a further understanding of infochemicals beyond laboratory systems.
