COMUNIDADE MICROZOOPLANCTÔNICA DE UM ESTUÁRIO TROPICAL DOMINADO POR RIO – PARQUE NACIONAL DOS LENÇÓIS MARANHENSES

Abstract

Studies of zooplankton distribution patterns and diversity associated with environmental environmental heterogeneity are important for understanding the basic structure and function of coastal ecosystems. The study emphasized the importance of environmental filters in the dynamics microzooplankton community and the ecological relationships established with phytoplankton in three zones in the tropical mesomare estuary. The microzooplankton recorded a total of 89 species, belonging to 14 phyla, with Arthropoda being the most representative (72.21%), followed by the Ciliphora and Mollusca. The class Copepoda stands out, with the species Paracalanus crassiostris, Pseudodiaptomus gracilis and Oithona nana dominating the the community. From the total, 21 species were selected as indicators, highlighting Temora turbinata in the coastal zone (CZ), Rhizodomus tagatzi in the mixing zone (MZ) and Bosminopsis deitersi in the river zone (ZR). The environmental heterogeneity showed significant spatial differences, with variations governed mainly by the gradient of salinity temperature and pH, which acted as the main environmental filters. The species species of ZC and ZM showed direct ecological relationships with the diatom blooms Skeletonema costatum and Asterionellopsis glacialis, which favored the abundance of microzooplankton was favored by their occurrence, denoting a top-down control of the trophic web. trophic network. When the partitioning of beta diversity, the turnover component was responsible for the high diversity, due to the environmental heterogeneity, which distinguished communities between zones. The MZ acted as a dispersive center, with 58% of its species migrating between all zones, thus defining it as an area that requires greater protection of biodiversity.