Changes in phytoplankton composition in response to tides, wind-induced mixing conditions, and freshwater outflows in an urbanised estuarine complex

Autor(es)

Moser, G. A. O. ^[1] ; Ciotti, A. M. ^[2] ; Giannini, M. F. C. ^[2] ; Tonini, R. T. ^[2] ; Harari, J. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estado Rio de Janeiro UERJ, Fac Oceanog, BR-20550103 Rio De Janeiro, RJ - Brazil

^[2] Univ Estadual Paulista Julio de Mesquita Filho UN, BR-11330900 Sao Vicente, SP - Brazil

^[3] Univ Sao Paulo, IO, BR-05508120 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Biology; v. 72, n. 1, p. 97-111, FEB 2012.
• Citações Web of Science: 10

Resumo

Recent reports have shown an increase in potentially harmful phytoplankton in Santos bay (Southeastern Brazilian Coast), located in a highly urbanised estuarine complex. Prediction of blooms is, thus, essential but the phytoplankton community structure in very dynamic regions is difficult to determine. In the present work, we discriminate bloom forming microphytoplankton dominance and their relationship to physical and meteorological variables to look for patterns observed in different tides and seasons. Comparing 8 distinct situations, we found five scenarios of dominance that could be related to winds, tides and rainfall: i) Surfers, diatoms occurring during high surf zone energies; ii) Sinkers, represented by larger celled diatoms during spring tide, after periods of high precipitation rates; iii) Opportunistic mixers, composed of chain forming diatoms with small or elongate cells occurring during neap tides; iv) Local mixers, microplanktonic diatoms and dinoflagellates which occurred throughout the 298 sampling stations; and v) Mixotrophic dinoflagellates, after intense estuarine discharges. Results suggest alterations in the temporal patterns for some bloom-forming species, while others appeared in abundances above safe limits for public health. This approach can also illustrate possible impacts of changes in freshwater discharge in highly urbanised estuaries. (AU)

• Processo FAPESP: 03/13747-5 - Análise da variabilidade sazonal da circulação do Estuário de Santos (SP)
• Beneficiário: Joséph Harari
• Modalidade de apoio: Auxílio à Pesquisa - Regular