Habitat-mediated soundscape conservation in marine ecosystems

Abstract

The nexus between changing habitats, faunal communities, and anthropogenic stressors represents an enduring conservation challenge. We propose that habitat-mediated soundscape conservation—the ability of biogenic habitats to attenuate anthropogenic noise—plays an unrecognized role in mitigating underwater noise pollution, a pervasive disturbance that disrupts the ability of species to perceive acoustic cues and communicate. We hypothesize that noise attenuation depends on the composition and physical complexity of biogenic habitats, and severe habitat degradation can cause acoustic conditions to exceed ecological tipping points, resulting in the emergence of alternative acoustic states. We examine this concept in coral reefs and kelp forests, given that the global decline of both ecosystems provides the requisite conditions to investigate our hypothesis. We then explore why anthropogenic structures fail to provide acoustic refugia. Finally, we assess whether habitat restoration or acoustic enrichment can reestablish natural soundscapes. Our review underscores the importance of considering habitat degradation when evaluating the risk that pollutants pose to ecosystems.