Oecologia DOI 10.1007/s00442-007-0773-4 123 COMMUNITY ECOLOGY Habitat choice, recruitment and the response of coral reef Wshes to coral degradation David A. Feary · Glenn R. Almany · Mark I. McCormick · GeoVrey P. Jones Received: 8 February 2007 / Accepted: 9 May 2007  Springer-Verlag 2007 Abstract The global degradation of coral reefs is having profound eVects on the structure and species richness of associated reef Wsh assemblages. Historically, variation in the composition of Wsh communities has largely been attributed to factors aVecting settlement of reef Wsh larvae. However, the mechanisms that determine how Wsh settlers respond to diVerent stages of coral stress and the extent of coral loss on Wsh settlement are poorly understood. Here, we examined the eVects of habitat degradation on Wsh set- tlement using a two-stage experimental approach. First, we employed laboratory choice experiments to test how set- tlers responded to early and terminal stages of coral degra- dation. We then quantiWed the settlement response of the whole reef Wsh assemblage in a Weld perturbation experi- ment. The laboratory choice experiments tested how juve- niles from nine common Indo-PaciWc Wshes chose among live colonies, partially degraded colonies, and dead colo- nies with recent algal growth. Many species did not distin- guish between live and partially degraded colonies, suggesting settlement patterns are resilient to the early stages of declining coral health. Several species preferred live or degraded corals, and none preferred to associate with dead, algal-covered colonies. In the Weld experiment, Wsh recruitment to coral colonies was monitored before and after the introduction of a coral predator (the crown-of-thorns starWsh) and compared with undisturbed control colonies. StarWsh reduced live coral cover by 95–100%, causing per- sistent negative eVects on the recruitment of coral-associated Wshes. Rapid reductions in new recruit abundance, greater numbers of unoccupied colonies and a shift in the recruit community structure from one dominated by coral-associated Wshes before degradation to one predominantly composed of algal-associated Wsh species were observed. Our results suggest that while resistant to coral stress, coral death alters the process of replenishment of coral reef Wsh communities. Keywords Coral reef Wshes · Habitat loss · Settlement Introduction Habitat loss and degradation have been major factors responsible for declining populations (Vitousek et al. 1997), loss of biodiversity (Brooks et al. 2002) and the dis- ruption of ecosystem services (McCarty 2001; Malcolm et al. 2006) in terrestrial environments. It has been esti- mated that almost one-half of the land surface has been modiWed by human activities (Vitousek et al. 1997) and more extinctions have been attributed to habitat loss than any other factor (Dirzo and Raven 2003). Terrestrial habitat loss or alteration has been caused by a number of mecha- nisms, including human predation and extinction of impor- tant predators and herbivores (Lyons et al. 2004), habitat transformation for farming or development (Vitousek et al. 1997), introduction of exotic species (Seabloom et al. 2006) and most recently climate change (Sala et al. 2000; Walther et al. 2002). One of the central issues in conservation biology has been to identify the characteristics that render species prone to habitat change (Lampila et al. 2005; Cushman 2006). A key Communicated by Roland Brandl. D. A. Feary (&) · G. R. Almany · M. I. McCormick · G. P. Jones Australian Research Council, Centre of Excellence for Coral Reef Studies, School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia e-mail: david.feary@jcu.edu.au