Ocean acidification leaves dispersing fish larvae lost at sea

Chair: Martin Grosell

Tullio Rossi, Ivan Nagelkerken and Sean D. Connell

Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, DX 650 418, The University of Adelaide, Adelaide, SA 5005, Australia.

Abstract

The dispersal of larvae and their settlement to suitable habitat is fundamental to replenishment of marine populations and the communities in which they live. Sound is a critical part of this process for some species because it can act as a cue for larvae to orientate towards suitable settlement habitat. Because marine sounds are largely of biological origin, they not only carry information about the location of potential habitat, but also information about the quality of habitat. While ocean acidification is known to have profound effects on marine life, its effect on biological sound production and its reception by navigating oceanic larvae remains unknown. Here we show that ocean acidification can profoundly alter biological sound quantity and quality of future soundscapes. A quieter soundscape indirectly penalizes oceanic larvae by reducing the detection range of coastal habitats. Remarkably, ocean acidification also caused a switch in role of marine sound cues from attractor to repellent in the auditory preferences of fish larvae. Both of these indirect and direct effects of ocean acidification put at risk the complex processes of larval orientation, settlement, and habitat connectivity.