Unravelling life-history variation in coral reef fishes: it's more complex than you think
Investigations of phenotypic plasticity help to identify the capacity of populations to achieve local adaptation, thereby linking ecological and evolutionary processes. Given the direct link between life-history traits (such as growth rate and asymptotic body size) and ecosystem-level parameters that indicate overall ecosystem functioning (such as secondary biomass production), identifying the hierarchy of underlying drivers of demographic variation represents a paramount objective in the study of coral-reef ecosystems. Throughout the tropics, coral-reef fishes have high cultural, economic, and ecological value through strong linkages to coral-reef benthic environments, tourism, and commercial and artisanal fisheries. Further, the incredibly high diversity of tropical reef fish species, of life-history strategies, and the array of competitive and trophic interactions among species make these taxa ideal subjects for addressing ecological hypotheses and research questions of management and conservation value. This talk summarizes ongoing research in the Pacific region and elsewhere to understand how and why tropical ectotherms vary across space in life-history traits such as body size and life span. The processes underlying patterns of spatial variation range from straightforward to perplexing; the distinction often hinges on the spatial scale of observation and the complexity of the system. Some fundamental questions are: What drives demographic variation at different spatial scales? How do evolutionary history and environmental disturbance regime affect life-history strategies? What effects will climate change have on biomass production in tropical reef fish communities? We are beginning to answer some of these questions but there is plenty of work to do.