Using chemical language to shape future marine health

“Infochemicals” (information‐conveying chemicals) dominate much of the underwater communication in biological systems. They influence the movement and behavior of organisms, the ecological interactions between and across populations, and the trophic structure of marine food webs. However, relative to their terrestrial equivalents, the wider ecological and economic importance of marine infochemicals remains understudied and a concerted, cross‐disciplinary effort is needed to reveal the full potential of marine chemical ecology. We highlight current challenges with specific examples and suggest how research on the chemical ecology of marine organisms could provide opportunities for implementing new management solutions for future “blue growth” (the sustainable use of ocean resources) and maintaining healthy marine ecosystems. Approximately 1500 different spoken languages currently exist, with ~100 of the most commonly used ones making up the great majority of global human conversation. Language is not only an important part of one's identity and cultural background, but is also a prerequisite for social interactions, social behavior, and a functioning society. However, species other than humans also “talk”, and this chatter is not limited to the terrestrial world. Underwater communication is bountiful although somewhat alien to us because it relies on means of communication that extend well beyond the audible clicking sounds produced by dolphins or the “singing” of whales. For example, glows and flashes from the light‐producing organs of deep‐sea fishes attract prey and mates or stun and confuse prey and predators (Haddock et al. 2010). Although sharks employ a range of sensory systems that include vision, touch, electroreception, and specialized organs (lateral lines) that detect water turbulence (Gardiner 2012), they also exploit chemical cues to locate prey over distances of several hundred meters (see Panel 1 for a glossary of terms; Gardiner et al. 2014). In the marine realm, use of such cues is not limited to top predators but is also very common among organisms at the microscopic scale. For instance, plankton rely on chemicals to deter enemies or synchronize mutual as well as inhibitory or “allelopathic” interactions that critically affect marine community structure and ecosystem function (reviewed by Hay 2009). The study of such chemical interactions among organisms and their environment is referred to as “chemical ecology”, which aims to translate this chemical “language” so as to interpret behaviors, processes, and functions (Hay 2014). Over