Hierarchical organization of spatial and temporal patterns of macrobenthic assemblages in the tropical Pacific continental shelf

Abstract

[Abstract] 1. Nowadays, studies focused to test a well-defined set of a priori hypotheses about spatial and temporal organization of assemblages in marine communities are scarce. 2. This study presents the first fully-developed application of a parsimonious approach for model selection based on the Kullback-Leibler information theory using multivariate data to determine the best spatial and temporal models among a set of a priori alternative models of a soft bottom macroinvertebrate community in the tropical Pacific continental shelf (from 10 to 90 m deep). 3. Besides of the determination of the most parsimonious model, the Akaike´s information criterion allows the exploration of the scale-dependent patterns of community organization and to determine hierarchical relations among the gradients considered. 4. Depth the most conspicuous spatial gradient affecting macrofaunal assemblages, and the main discontinuity is located between 40 and 60 m. The degree of exposure is defined as a secondary gradient and it is only relevant in shallow waters. 5. Seasonal changes in the abundance along the bathymetric gradient of some portunid crabs and shrimps defined a process of seasonal recomposition, caused by a vertical shift of the community.