REPORT Patterns of recruitment and microhabitat associations for three predatory coral reef fishes on the southern Great Barrier Reef, Australia C. K. C. Wen • M. S. Pratchett • G. R. Almany • G. P. Jones Received: 4 March 2012 / Accepted: 15 November 2012 Ó Springer-Verlag Berlin Heidelberg 2012 Abstract This study examined recruitment patterns and microhabitat associations for three carnivorous fishes, Plectropomus maculatus, Lutjanus carponotatus and Epinephelus quoyanus, at the Keppel Islands, southern Great Barrier Reef, Australia. Habitat selectivity was highest for recruits that were found mostly with corymbose Acropora, predominantly on patches of live coral located over loose substrates (sand). Adults were more commonly associated with tabular Acropora. The proportion of P. maculatus (72 %) found with live corals was higher than for L. carponotatus (68 %) and E. quoyanus (44 %). Densities of recruits were highly variable among locations, but this was only partly related to availability of preferred microhabitats. Our findings demonstrate that at least some carnivorous reef fishes, espe- cially during early life-history stages, strongly associate with live corals. Such species will be highly sensitive to increasing degradation of coral reef habitats. Keywords Coral reefs  Coral trout  Habitat use  Plectropomus Introduction A large proportion of coral reef fishes have very specific microhabitat requirements. Jones et al. (2004) suggested that up to 75 % of reef fish species rely on individual coral heads for food, shelter or recruitment substrata. Moreover, both abundance (Carpenter 1981; Jennings et al. 1996; Findley and Findley 2001) and diversity (Bell and Galzin 1984; Sano et al. 1984; Bouchon-Navaro and Bouchon 1989; Chabanet et al. 1997; Munday 2004) of coral reef fishes is often positively correlated with live coral cover. Declines in live coral cover, reported for many coral reef ecosystems around the world (Gardner et al. 2003; Bell- wood et al. 2004; Bruno and Selig 2007; De’ath et al. 2012) will therefore affect many species of coral reef fishes (Sano et al. 1987; Jones et al. 2004; Pratchett et al. 2008a). Effects of coral loss on fishes are most apparent among highly specialised coral-dependent species, including but- terflyfishes, damselfishes and gobies (Munday et al. 1997; Syms and Jones 2000; Booth and Beretta 2002; Pratchett et al. 2006). However, some larger, carnivorous species such as coral trout (Plectropomus spp.) also decline in abundance following extensive coral loss (Graham et al. 2007; Russ et al. 2008). On the Great Barrier Reef (GBR), for example, densities of coral trout (Plectropomus spp.) declined [ 20 % following severe coral loss at the Keppel Islands in 2006 (Russ et al. 2008). Mechanisms underlying these effects are unclear because there little is known about specific habitat requirements of such fishes. Reef fishes that do not typically feed on, or live within, live coral are nonetheless dependent on live coral, and may be negatively affected by coral loss (e.g. Jones et al. 2004; Wilson et al. 2006, Graham et al. 2007). These fishes may indirectly depend on coral-dominated habitats for access to prey (Westmacott et al. 2000) or to moderate competition Communicated by Biology Editor Dr. Hugh Sweatman C. K. C. Wen  G. P. Jones School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4814, Australia C. K. C. Wen  M. S. Pratchett (&)  G. R. Almany  G. P. Jones ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4814, Australia e-mail: morgan.pratchett@jcu.edu.au 123 Coral Reefs DOI 10.1007/s00338-012-0985-x