Spatial and temporal changes in interstitial meiofauna on a sandy ocean beach of South America

Abstract

Spatial and temporal patterns of meiofauna community from a Brazilian sandy beach were investigated. The objective of this work was to analyze the meiofauna distribution using a statistical model that considers the biological data as variables, and granulometric characteristics, organic matter, and temperature as covariables.Four zones were sampled throughout one year in a Brazilian sandy beach and three sediment cores were taken monthly from each zone. The meiofauna was composed by 12 taxa, with tardigrades and nematodes comprising 92% of the total fauna. The meiofauna mean density varied from 1556.25 to 13125.25 ind.10 cm-2, with the highest densities in December. The results of multiple regression showed that the mean effects of zones, vertical layers, and months on the organisms were significantly correlated with the principal taxa of meiofauna. The retention zone and the 0-10 cm layer presented the highest densities. The temporal distribution showed different patterns and some taxa were more abundant in the dry season, and others in the rainy season. Sedimentological variables had strong and significant effects on the meiofauna taxa. According to the results, physical variables at the retention zone create optimal living conditions for the meiobentos, making this zone an area that favors the basic and applied ecological studies.