Padrões de dispersão, distribuição espaço-temporal e bioindicadores ambientais da macrofauna bentônica de substrato não consolidado na Baía de Guanabara

Abstract

Benthic invertebrates are sensitive to natural and/or anthropogenic changes. Species distribution was studied from 2005 to 2007 with samples collected in ten seasons during six campaigns (dry, pre and post-rainy). At each station, ten replicas were collected with Gravity corer or by free diving. Abiotic data were collected with a van Dorn bottle (bottom water) and Ekman bottom search (granulometry). The stations were grouped into sectors (Input, Intermediate and Internal) based on abiotic data and location. The unconsolidated substrate mosaic infers that structural variables and temporal distribution patterns were influenced by parameters that indicate pollution and intrusion of ACAS (South Atlantic Central Water). Scenarios of dispersion of benthic invertebrates in the water column (hyperbenthos) for saline and surface intrusion were elaborated under the following metoceanographic conditions: good x bad weather, spring x square tide and winter x summer. The RDA and RDA Parsimonious for all years and separately showed indicator taxa with high dominance in the sectors. Bivalves of the species Ervilia concentrica and ostracodes of the family Cypridinidae are indicators of natural and/or anthropogenic changes in the Entrance, while ostracodes Cyprideis salebrosa and Cyprideis sp. for the Intermediate and gastropod Heleobia australis for the Internal. PERMANOVA indicated regular seasonality between campaigns for the first year (p<0.05) and an atypical pattern for the second (p>0.05), due to the low rainfall observed in this period, evidencing responses to climate change that were observed in other estuaries. Thus, it is suggested that they be used as bioindicators for short, medium and long term natural and/or anthropogenic changes in coastal and estuarine systems.