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Effects of Minor Coral Bleaching Events on Juvenile Butterflyfishes
Paper Reviewed
Cole, A.J., Lawton, R.J., Pisapia, C. and Pratchett, M.S. 2014. The effects of coral bleaching on settlement preferences and growth of juvenile butterflyfishes. Marine Environmental Research 98: 106-110.

Cole et al. (2014) write that the types of fish that are most harmed by declining coral cover "are coral-dependent species, such as the obligate coral-feeding butterflyfishes," citing Wilson et al. (2006, 2013) and Pratchett et al. (2008a), while further noting, in this regard, that several studies have documented "disproportionate declines in the abundance of coral-feeding fishes following severe coral bleaching and coral loss," citing Kokita and Nakazono (2001), Sano (2004), Wilson et al. (2006) and Pratchett et al. (2006). However, they state that "the effects of short-term or minor bleaching events that do not cause extensive coral mortality are much less clear."

Hoping to bring some clarity to the subject, Cole et al. explored "whether there was a difference in the growth and condition of juvenile butterflyfishes inhabiting bleached versus healthy corals," while also examining "whether habitat condition (healthy, bleached and recently dead coral colonies) influenced the patterns of habitat use by juvenile butterflyfishes," which in their case were the species Chaetodon aureofasciatus and Chaetodon lunulatus, both of which settle exclusively to distinct colonies of branching corals (Pratchett et al., 2008b), and which in their case had recruited in very high abundance to reef habitats on the western side of Lizard Island, northern Great Barrier Reef, Australia, at the time of their study.

The four Australian researchers report finding that "coral condition (bleached vs. unbleached) had no significant effects on changes in [butterflyfish] total length or weight over a 23-day period." Likewise, in a habitat choice experiment, they found that "juvenile butterflyfishes did not discriminate between healthy and bleached corals," although they "actively avoided using recently dead colonies." Cole et al. concluded that "reef fish communities do appear to exhibit a higher tolerance for bleached coral than initially suspected," highlighting the fact that "juvenile coral-feeding fishes are relatively robust to short term effects of bleaching events."

Kokita, T. and Nakazono, A. 2001. Rapid response of an obligately corallivorous filefish Oxymonacanthas longirostris (Monacanthidae) to a mass coral bleaching event. Coral Reefs 20: 155-158.

Pratchett, M.S., Wilson, S.K. and Baird, A.H. 2006. Declines in the abundance of Chaetodon butterflyfishes following extensive coral depletion. Journal of Fish Biology 69: 1269-1280.

Pratchett, M.S., Munday, P.L., Wilson, S.K., Graham, N.A.J., Cinner, J.E. and Bellwood, D.R. 2008a. Effects of climate-induced coral bleaching on coral-reef fishes: ecological and economic consequences. Oceanography and Marine Biology Annual Review 46: 251-296.

Pratchett, M.S., Marnane, M.J.,Berumen, M.L., Eagle, J.E. and Pratchett, D.J. 2008b. Habitat associations of juvenile versus adult butterflyfishes. Coral Reefs 27: 541-551.

Sano, M. 2004. Short-term effects of a mass coral bleaching event on a reef fish assemblage at Iriomote Island, Japan. Fisheries Science 70: 41-46.

Wilson, S.K., Graham, N.A.J. and Pratchett, M.S. 2013. Susceptibility of butterflyfish to habitat disturbance: do 'chaets' ever prosper? In: Pratchett, M.S., Berumen, M.I. and Kapoor, B. (Eds.), Biology of Butterflyfishes. CRC Press, Boca Raton, Florida, USA, pp. 226-245.

Wilson, S.K., Graham, N.A.J., Prachett, M.S., Jones, G.P. and Polunin, N.V.C. 2006. Multiple disturbances and the global degradation of coral reefs: are reef fishes at risk or resilient? Global Change Biology 12: 2220-2234.

Reviewed 17 September 2014