Comparison of zooplankton community structure between impacted and non-impacted areas of Paranaguá Bay Estuarine Complex, south Brazil

Abstract

We analysed the seasonal distribution of the zooplankton community in an anthropogenically impacted area (Paranaguá Bay) and a non-impacted area (Laranjeiras Bay) of the Paranaguá Bay Estuarine Complex. Large phytoplankton (> 50 μm) and zooplankton were collected every two months, between August 2003 and June 2004. The phytoplankton community was numerically dominated by diatoms (78%) and dinoflagellates (19%). Zooplankton abundance varied between 670 and 100,716 individuals m^–3, with a dominance of copepods, mainly the calanoids Acartia lilljeborgii, Acartia tonsa and Pseudodiaptomus acutus. A clear seasonal pattern was observed: copepods were significantly more abundant during the rainy than in the dry season. Significant differences in abundance between the two bays were detected only for cirripede larvae, which were more abundant in Paranaguá Bay. This lack of difference between the two areas was probably a consequence of the water circulation along the estuary, which may have diluted and dispersed the pollutants from Paranaguá Bay to other areas of the estuary.

Keywords:

• Copepoda
• Paranaguá Port
• pollution
• estuary
• South Atlantic

Acknowledgements

This study was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq #142203/2010-6 to L.K.M., #134641/2005-1 to J.E.M.F. and #307928/2010-1 to R.M.L.). We thank Dr Jefferson Turner for English editing in an earlier version of this manuscript, and two reviewers for constructive comments.