Spatio-temporal sublittoral macrobenthic distribution and dominant species in Guanabara Bay, Rio de Janeiro, Brazil.

L A Pessoa,C A Echeverría,R R Paranhos,P C Paiva,Marcos A V Freitas

doi:10.1590/1519-6984.230792

L A Pessoa, C A Echeverría + Show 3 more

Open Access

https://doi.org/10.1590/1519-6984.230792

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Abstract

Soft-bottom macrobenthic invertebrates are sensitive to natural or anthropogenic changes in aquatic ecosystems. The distribution patterns of sublittoral macrobenthic species in Guanabara Bay were studied from 2005 to 2007. Samples were collected at ten stations during six surveys throughout the rainfall regime (dry, early and late rainy). Ten replicates were collected at each station by Gravity corer or skin diving. Van Dorn bottles (bottom water) and by Ekman sediment sampler (granulometry) provided material for abiotic data. Stations were grouped into sectors (Entrance, Intermediary and Inner) based on abiotic data and location. The Redundancy Analysis (RDA) and Parsimonious RDA for all years and each annual cycle showed indicator taxa with high dominance in each sector. PERMANOVA indicated a regular seasonality between the surveys for the first annual cycle (p <0.05), and an atypical pattern for the second (p> 0.05), possibly due the low rainfall observed during this period. The mosaic of soft-bottom substrates infers structural variables, and patterns of temporal distribution were basically influenced by parameters those indicating pollution and the SACW (South Atlantic Central Water) intrusion, as well as ecological attributes among species, such as: predation, competition. The Ervilia concentrica and Cypridinidae could be used as indicators for anthropic and natural impacts in the Guanabara Bay for the Entrance sector, while Cyprideis salebrosa and Cyprideis sp. for the Intermediary sector and Heleobia australis for the Inner sector.

Highlights

As sediments are present in almost all aquatic ecosystems (Snelgrove, 1997), all or at least part of the life cycles of a large number of species is associated with them (Alongi, 1989; Day et al, 1989)
The aim of this study is to evaluate the influence of seasonality on macrobenthic community within the Guanabara Bay estuary system
The others dominants were Cyprideis sp. (Ostracoda/1,802 ind. ~ 10%), Americuna besnardi (Gastropoda/768 ind. ~4.5%), Cyprideis salebrosa (Ostracoda/486 ind. 2.7%), Ervilia concentrica (Gastropoda/377 ind. 2.1%), Mytilidae (350 ind. ~2%), Cypridinidae (347 ind. ~2%) and the remaining taxa a total of the 3,575 ind. distributed in 117 taxa with percentages below 2%

Summary

Introduction

As sediments are present in almost all aquatic ecosystems (Snelgrove, 1997), all or at least part of the life cycles of a large number of species is associated with them (Alongi, 1989; Day et al, 1989) Invertebrates living under these conditions resort to various strategies for feeding, dispersion, locomotion, among others (Gray and Elliott, 2009), that are relevant in the dynamics of aquatic ecosystems, as a whole. Macrobenthic samples retained after washing or sieving through a 0.5 mm mesh, are mainly comprised of polychaetes, crustaceans, molluscs and others (Little, 2000) Another vital aspect of dynamics is the presence of bioturbinators involved in nutrient recycling and aeration of the sediment. The measures for increasing oxic layers are exerted by the presence of species that rework the sediment through the formation of galleries (Diaz and Rosenberg, 1995; Mermillod-Blondin and Rosenberg, 2006; Rosenberg, 2001)

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