Climate change and biodiversity in Melanesia: implications for and impacts upon reef fishes

Abstract

Climate change poses a significant set of problems for reef fishes associated with coral reef systems, mainly from the negative effects of habitat loss from coral bleaching, ocean acidification, and subsequent physical degradation. The effects are direct (i.e., loss of obligate or facultative microhabitat, food supply or breeding sites) or indirect (i.e., effects of community phase shifts from coral to algal domination, effects on non-obligate coral reef species from loss of prey associated with corals, etc.). In addition, cumulative negative effects upon reef fish diversity and abundance from other sources. Exploitation and over-exploitation are expected to continue regardless of local and regional declines in the diversity and abundance of target species that may be affected directly or indirectly by climate change processes. Changes in the assemblage structure of reef fishes, and corresponding changes in ecological communities, because of climate change effects, will have profound effects upon human users of reef resources. Simple rules of thumb on how to proceed to conserve species in a relatively short time span are needed, as is the application of existing and new methodologies towards understanding how species will respond to habitat loss and what can be done to reduce extinction threats on local, regional and global scales.