SPATIAL AND TEMPORAL VARIABILITY IN THE COMPOSITION AND STRUCTURE OF MEIOBENTHIC ASSEMBLAGES (ESPECIALLY NEMATODES) IN TROPICAL BEACHES (GUADELOUPE, FWI)

Short term fluctuations in physical parameters are particularly import ant in determining faunal diversity of intertidal beaches, and the mai n objective of this paper is to describe the situation on the Caribbea n island of Guadeloupe with respect to the meiobenthos of this habitat . A meiofaunal inventory was established for 23 beaches in 1979 and si x representative beaches were surveyed five more times up to 1984. The proportions of higher meiofauna taxa present were highly variable in both space and time, and are shown to correlate with sediment grain-si ze and CaCO3, content. The nematode generic composition was highly var iable at the more wave-exposed locations, but less so at the more shel tered locations. There was a significant effect of grain-size on the g eneric composition of the samples, but not on univariate measures of s pecies diversity. Dominance patterns varied over time at a given locat ion, but the trends of variation are not consistent among stations. In terpretation of future changes in community composition in terms of an thropogenic activities must therefore be approached with caution. For example, changes which might be regarded as indicative of organic poll ution, such as switches from copepod dominance to nematode dominance, are shown to occur naturally over short periods of time (< 1 year) on the same beach.