• The good, the bad, and the distant: soundscape cues for larval fish

      Piercy, Julius J. B.; Smith, David J.; Codling, Edward A.; Hill, Adam J.; Simpson, Stephen D.; University of Essex; University of Exeter; University of Derby (2015-11)
      Coral reef noise is an important navigation cue for settling reef fish larvae and can thus potentially affect reef population dynamics. Recent evidence has shown that fish are able to discriminate between the soundscapes of different types of habitat (e.g., mangrove and reef). In this study, we investigated whether discernible acoustic differences were present between sites within the same coral reef system. Differences in sound intensity and transient content were found between sites, but site-dependent temporal variation was also present. We discuss the implications of these findings for settling fish larvae.
    • Habitat quality affects sound production and likely distance of detection on coral reefs

      Piercy, Julius J. B.; Codling, Edward A.; Hill, Adam J.; Smith, David J.; Simpson, Stephen D.; University of Essex; University of Derby; University of Exeter (2014-12-03)
      The interwoven nature of habitats and their acoustic fingerprints (soundscapes) is being increasingly recognized as a key component of animal ecology. Natural soundscapes are crucial for orientation in many different taxa when seeking suitable breeding grounds or settlement habitats. In the marine environment, coral reef noise is an important navigation cue for settling reef fish larvae and is thus a possible driver of reef population dynamics. We explored reef noise across a gradient of reef qualities, tested sound propagation models against field recordings and combined them with fish audio grams to demonstrate the importance of reef quality in determining which reefs larvae are likely to detect. We found that higher-quality reefs were significantly louder and richer in acoustic events (transient content) than degraded reefs, and observed that sound propagated farther with less attenuation than predicted by classic models. We discuss how zones of detection of poor-quality reefs could be reduced by over an order of magnitude com-pared to healthy reefs. The present study provides new perspectives on the far reaching effects habitat degradation may have on organisms that utilize soundscapes for orientation towards or away from coral reefs, and highlights the value of sound recordings as a cost-effective reef survey and monitoring tool.