Metacommunity analysis of meiobenthos of deep-sea sediments from the Gulf of Mexico

Abstract

Metacommunity theory is a conceptual framework addressing the interdependence of local interactions and regional processes, especially when it is difficult to relate community structure and the environment at different spatial scales. To test the applicability of this theory to meiobenthos, 27 deep-sea sediment samples from the Gulf of Mexico were analyzed for meiobenthic and nematode community distribution and structure along with a set of environmental variables. Spatial and temporal heterogeneity in environmental conditions were found among sampling stations, and some variables, such as depth, inorganic carbon, carbon/nitrogen ratio, bottom-water oxygen, and percentage of sand, proved influential on total community abundance. Nematodes were the dominant meiofaunal group and its abundance highly variable among sites and sampling periods. Nematofauna was dominated by bacterivores, which also possessed the highest maturity index. Environmental characteristics showed a significant relation with community structure, not so the dispersal of nematode genera. In light of our findings, we posit that the deep-sea meiobenthos of the Gulf of Mexico may represent a metacommunity following the “species-sorting model.” This inference is based on the different taxonomic structures among sampling stations correlating with environmental differences, in the presence of local niche diversification and limited dispersal.