Coral reef soundscapes and noise

Abstract

Building back coral reefs requires limiting greenhouse gas emissions, limiting local threats, and active restoration. Vessel noise pollution is a widespread threat acting at a local level impacting a broad range of species from cetaceans to cephalopods. Ultimate consequences of noise pollution include death due to injury or predation, failure to develop and reduced offspring quality and survival. We tested the hypothesis that protecting coral reefs from motorboat noise can improve reproductive output in fish on the Great Barrier Reef in Australia. Across an entire breeding season, we limited motorboat traffic at three separate reefs with breeding spiny chromis. We compared these protected nests with nests on three further reefs where motorboats drove regularly nearby. We replicated the breeding experiment in a laboratory setting to isolate noise as the stimulus. Protecting coral reefs from traffic noise was beneficial for breeding fish and their offspring: egg fanning and offpsring growth were enhanced with lower energetic resource use, and reproductive success was enhanced. Limiting traffic noise at the local level presents a valuable opportunity for enhancing resilience in coral reefs by improving reproductive success in fish. This could speed up recovery following climate related mass mortality events caused by bleaching and cyclones.