Discussion
Strikingly, nearly 70% of Pocillopora corals bleached and died between August 2007 and July 2008 at our three study sites in the Galápagos, which coincided with the 2007-2008 La Niña-related cold-water anomaly. This represents a major loss of live coral foundational habitat for associated fishes and mobile macroinvertebrates. Nevertheless, dead coral colonies were still able to retain the ecosystem function of hosting high species richness of associated fish and mobile macroinvertebrates for more than two years after the disturbance. However, the species composition of these assemblages (and particularly of invertebrates) significantly varied between mutualistic xanthid crabs on live corals to opportunistic and predatory pencil urchins, hermit crabs, and gastropod snails on dead corals, and shifted over time on live and dead corals. This shift in associated species composition was likely due to changes in structure and provisioning of food on coral tissue, and loss or growth of live coral tissue. Furthermore, the speciose and opportunistic associated assemblage on dead corals ultimately declined in richness due to erosion and disappearance of complex coral structure, and likely led to loss of coral-associated richness after 32-49 months.