Partitioning Spatial Variation of Juvenile Corals,from Few Centimeters to Kilometers: A Case Study from Mochima National Park, Venezuela.

Coral recruitment refers to the processes allowing maintenance and renewal of coral communities. Recruitment success is therefore indispensable for coral reef recovery after disturbances. Recruitment processes are governed by a variety of factors occurring at all spatial and temporal scales, from centimetres to hundreds of kilometres. In the present context of rising disturbances, it is thus of major importance to better understand the relative importance of different scales in this variation. Successful recruitment and survivorship of juveniles is important for shaping the community structure and population dynamics of corals. In Venezuela, most studies have focused on describing the structure of adult coral communities, while corals in their early stages have received less attention.

This study aimed to determine spatial variability of juvenile corals abundance at different spatial scales in Venezuela, in Mochima National Park, Cubagua and Los Frailes. We also tested whether brooders were more abundant than spawnners. For this, we used a fully-nested design encompassing four scales: (1) three localities  (distanced by hundreds of kilometers), (2) twelve sites (distanced by tens of kilometers), (3) four transects within sites (distanced by 5-10 m), (4) fifteen 80x90 cm2 photoquadrats within each transect (distanced by 2 m) and finally, four 25x25 cm sub-quadrats within each quadrat separated to each other by 10-20 cm as replicates. The variance component was estimated for each source of variation with an analysis of variance based on permutation (PERMANOVA). Our study is the first to investigate and measure spatial variation of juvenile corals in Venezuela; and suggests that small-scale processes might play a key role for shaping these communities.

The variability of recruitment patterns at various spatial scales emphasises the importance of micro- to macro-local variations of the environment in the dynamics and maintenance of coral populations. In this study the smallest spatial scales have more impact in the variability patterns.