Scales of recruitment of Caribbean reef fishes.
Fisher, Rebecca*,1, Hogan, Derek1, Sale, Peter1, 1 Department of Biology, Unviersity of Windsor, Windsor, Ontario, Canada
ABSTRACT- Empirical evidence suggests that competition for limiting resources cannot explain the spatial and temporal variability in abundance found in reef fish populations. It is suggested that most reef fish populations are recruitment limited. As a result, variability in supply of larval fishes is likely to have the largest effect on dynamics and demographics of populations. Recruitment can be used to forecast the dynamics and demographics of populations. Recruitment can infer the abundance of larval fishes, therefore can be used to define the scales at which pelagic processes act to cause variation in supply. The purpose of this study is to define the scales at which recruitment is most variable, and to generate hypotheses about the factors that likely affect recruitment. Recruitment of 17 focal species was monitored over the span of 3 summers across 21 sites in the Mesoamerican Barrier Reef System (MBRS). Recruitment coherency, a measure of similarity, was calculated for each unit of a given spatial or temporal scale (e.g: site vs. site or year vs. year comparison). The coherency of recruitment across all species tended to decrease with increasing spatial scale, also, coherency tended to increase with increasing temporal scale. These results suggest that regional scale processes acting in short temporal time frames (i.e. storms, current patterns) tend to cause variation in recruitment. Furthermore, there was little effect of habitat on recruitment coherence at larger spatial scales, alternatively, distance between sites and locations was correlated with coherence.
Key words: recruitment, reef fish, larval dispersal, settlement
All materials copyright The Ecological Society of America (ESA), and may not be used without written permission.