Sediment pollution impacts sensory ability and performance of settling coral-reef fish
- 817 Downloads
Marine organisms are under threat globally from a suite of anthropogenic sources, but the current emphasis on global climate change has deflected the focus from local impacts. While the effect of increased sedimentation on the settlement of coral species is well studied, little is known about the impact on larval fish. Here, the effect of a laterite “red soil” sediment pollutant on settlement behaviour and post-settlement performance of reef fish was tested. In aquarium tests that isolated sensory cues, we found significant olfaction-based avoidance behaviour and disruption of visual cue use in settlement-stage larval fish at 50 mg L−1, a concentration regularly exceeded in situ during rain events. In situ light trap catches showed lower abundance and species richness in the presence of red soil, but were not significantly different due to high variance in the data. Prolonged exposure to red soil produced altered olfactory cue responses, whereby fish in red soil made a likely maladaptive choice for dead coral compared to controls where fish chose live coral. Other significant effects of prolonged exposure included decreased feeding rates and body condition. These effects on fish larvae reared over 5 days occurred in the presence of a minor drop in pH and may be due to the chemical influence of the sediment. Our results show that sediment pollution of coral reefs may have more complex effects on the ability of larval fish to successfully locate suitable habitat than previously thought, as well as impacting on their post-settlement performance and, ultimately, recruitment success.
KeywordsBehavioural ecology Coral reefs Environmental pollution Larval settlement Olfaction
The authors would like to thank the staff at the Tropical Biosphere Research Centre (University of the Ryukyus) for their logistical support, and the Australian Museum, the Sydney Institute of Marine Science and the University of Technology Sydney for their financial support. We also thank Ryuta Suzuki and Yasuaki Tanaka for assistance with the field and laboratory experiments. This research was carried out in accordance with Japanese law and was supported by the Japan Society for the Promotion of Science (Grant No. 24780188). All applicable institutional and/or national guidelines for the care and use of animals were followed.
- Edinger EN, Risk MJ (2013) Effect of land-based pollution on central Java coral reefs. Coast Dev 3:593–613Google Scholar
- Fiksen Ø, Aksnes DL, Flyum MH, Giske J (2002) The influence of turbidity on growth and survival of fish larvae: a numerical analysis. Sustainable increase of marine harvesting: fundamental mechanisms and new concepts. Springer, Berlin, pp 49–59Google Scholar
- Higashi T, Katayama TC, Shinagawa A (1985) Land development works and soil erosion in Okinawa Prefecture. Mem Kagoshima Univ Res Center S Pac 6:26–36Google Scholar
- Kingsford MJ, Leis JM, Shanks A, Lindeman KC, Morgan SG, Pineda J (2002) Sensory environments, larval abilities and local self-recruitment. Bull Mar Sci 70:309–340Google Scholar
- Okinawa Prefecture (1993) Survey report on the state of red soil pollution and its damage. Department of Health and Environment Okinawa, Naha, p 204Google Scholar
- Siebeck UE, O’Connor J, Braun C, Leis JM (2015) Do human activities influence survival and orientation abilities of larval fishes in the ocean? Integr Zool 10:65–82. doi: 10.1111/1749-4877.12096
- Torres JL, Morelock J (2002) Effect of terrigenous sediment influx on coral cover and linear extension rates of three Caribbean massive coral species. Caribb J Sci 38:222–229Google Scholar
- Wenger A, McCormick M, Endo G, McLeod I, Kroon F, Jones G (2014) Suspended sediment prolongs larval development in a coral reef fish. J Exp Biol 217:1122–1128. doi: 10.1242/jeb.094409