Habitat degradation negatively affects auditory settlement behavior of coral reef fishes (article)
Proceedings of the National Academy of Sciences
National Academy of Sciences
This open access article is distributed under Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CC BY-NC-ND).
Coral reefs are increasingly degraded by climate-induced bleaching and storm damage. Reef recovery relies on recruitment of young fishes for the replenishment of functionally important taxa. Acoustic cues guide the orientation, habitat selection, and settlement of many fishes, but these processes may be impaired if degradation alters reef soundscapes. Here, we report spatiotemporally matched evidence of soundscapes altered by degradation from recordings taken before and after recent severe damage on Australia's Great Barrier Reef. Postdegradation soundscapes were an average of 15 dB re 1 µPa quieter and had significantly reduced acoustic complexity, richness, and rates of invertebrate snaps compared with their predegradation equivalents. We then used these matched recordings in complementary light-trap and patch-reef experiments to assess responses of wild fish larvae under natural conditions. We show that postdegradation soundscapes were 8% less attractive to presettlement larvae and resulted in 40% less settlement of juvenile fishes than predegradation soundscapes; postdegradation soundscapes were no more attractive than open-ocean sound. However, our experimental design does not allow an estimate of how much attraction and settlement to isolated postdegradation soundscapes might change compared with isolated predegradation soundscapes. Reductions in attraction and settlement were qualitatively similar across and within all trophic guilds and taxonomic groups analyzed. These patterns may lead to declines in fish populations, exacerbating degradation. Acoustic changes might therefore trigger a feedback loop that could impair reef resilience. To understand fully the recovery potential of coral reefs, we must learn to listen.
This work was supported by funding from the Natural Environment Research Council Research Grant NE/P001572/1 (to S.D.S. and A.N.R.), an NERC-Australian Institute of Marine Science CASE GW4+ Studentship NE/L002434/1 (to T.A.C.G.), and an NERC-Marine Scotland Science CASE GW4+ Studentship NE/L002434/1 (to H.R.H.); the Royal Society Research Grant RG160452 (to S.D.S. and A.N.R.); the University of Exeter (S.D.S.); the Australian Research Council Discovery Grant DP170103372 (to M.I.M.); the Australian Institute of Marine Science (M.G.M.); and Cefas (N.D.M.).
This is the final version of the article. Available from National Academy of Sciences via the DOI in this record.
The dataset associated with this article is located in ORE at: http://hdl.handle.net/10871/32469
Published online April 30, 2018
Place of publication