Bottom-up processes mediated by social systems drive demographic traits of coral-reef fishes
MetadataShow full item record
© 2018 Ecological Society of America. Ectotherms exhibit considerable plasticity in their life-history traits. This plasticity can reflect variability in environmental and social factors, but the causes of observed patterns are often obscured with increasing spatial scales. We surveyed dichromatic parrotfishes across the northern Great Barrier Reef to examine variation in body size distributions and concomitant size at sex change (L 50 ) against hypotheses of directional influence from biotic and abiotic factors known to affect demography. By integrating top-down, horizontal, and bottom-up processes, we demonstrate a strong association between exposure regimes (which are known to influence nutritional ecology and mating systems) and both body size distribution and L 50 (median length at female-to-male sex change), with an accompanying lack of strong empirical support for other biotic drivers previously hypothesized to affect body size distributions. Across sites, body size was predictably linked to variation in temperature and productivity, but the strongest predictor was whether subpopulations occurred at sheltered mid and inner shelf reefs or at wave-exposed outer shelf reef systems. Upon accounting for the underlying influence of body size distribution, this habitat-exposure gradient was highly associated with further L 50 variation across species, demonstrating that differences in mating systems across exposure gradients affect the timing of sex change beyond variation concomitant with differing overall body sizes. We posit that exposure-driven differences in habitat disturbance regimes have marked effects on the nutritional ecology of parrotfishes, leading to size-related variation in mating systems, which underpin the observed patterns. Our results call for better integration of life-history, social factors, and ecosystem processes to foster an improved understanding of complex ecosystems such as coral reefs.
Showing items related by title, author, creator and subject.
Modern fringing reef carbonates from equatorial SE Asia: An integrated environmental, sediment and satellite characterisation study.Madden, Robert; Wilson, Moyra; O'Shea, M. (2013)Fringing reefs of SE Asia may conservatively comprise ~30% of the world’s coral reef area, but remain almost unstudied (White, 1987; Tomascik et al., 1997). This study provides insights into the primary sedimentological ...
Madden, Robert Henry Christopher (2013)This combined sedimentological, diagenetic and remote sensing study of SE Asian Cenozoic carbonate systems has implications for the understanding of how depositional and diagenetic conditions unique to the equatorial ...
Gradients of disturbance and environmental conditions shape coral community structure for south-eastern Indian Ocean reefsZinke, Jens; Gilmour, J.; Fisher, R.; Puotinen, M.; Maina, J.; Darling, E.; Stat, Michael; Richards, Zoe; Mcclanahan, T.; Beger, M.; Moore, C.; Graham, N.; Feng, M.; Hobbs, Jean-Paul; Evans, S.; Field, S.; Shedrawi, G.; Babcock, R.; Wilson, S. (2018)Aim: To describe, model and assess the relative importance of environmental and climatic factors likely influencing the regional distribution of coral cover and assemblages with contrasting life histories and susceptibilities ...