Rotifer abundance, biomass, and secondary production after the recovery of hydrologic connectivity between a river and two marginal lakes (Sao Paulo, Brazil)

Autor(es)

Caglierani Casanova, Silvia Maria ^[1] ; Panarelli, Eliana Aparecida ^[2] ; Henry, Raoul ^[1]

Afiliação do(s) autor(es)

^[1] State Univ Sao Paulo, Inst Biosci, Dept Zool, BR-18618000 Botucatu, SP - Brazil

^[2] Univ Estado Minas Gerais, Frutal, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: LIMNOLOGICA; v. 39, n. 4, p. 292-301, DEC 2009.
• Citações Web of Science: 16

Resumo

Rotifera density, biomass, and secondary production on two marginal lakes of Paranapanema River were compared after the recovery of hydrologic connectivity with the river (Sao Paulo State, Brazil). Daily samplings were performed in limnetic zone of both lakes during the rainy season immediately after lateral inflow of water and, in the dry period, six months after hydrologic connectivity recovery. In order to identify the factors that affect rotifer population dynamics, lake water level, volume, depth, temperature, transparency, dissolved oxygen, pH, alkalinity, conductivity, suspended solids, nutrients, and chlorophyll-a were determined. Variations of water physical and chemical factors that affect rotifer population were related to the lake-river degree of connection and to water level rising after drought. The water lateral inflow from the river resulted in an increase in lake water volume, depth, and transparency and a decrease in water pH, alkalinity, and suspended solids. The lake with the wider river connection, more frequent biota exchange, and larger amount of particulate and dissolved materials was richer and more diverse, while rotifer density, biomass, and productivity were lower in both periods studied. Density, biomass, and secondary production were higher in the lake with the smaller river connection and the higher physical and chemical stability. Our results show that the connectivity affects the limnological stability, associated to seasonality. Stable conditions, caused by low connectivity in dry periods, were related with high density, biomass and secondary production. Conversely, instability conditions in rainy periods were associated to elevated richness and diversity values, caused by exchange biota due to higher connectivity. (C) 2008 Elsevier GmbH. All rights reserved. (AU)

• Processo FAPESP: 99/08748-5 - Flutuações mensais da comunidade zooplanctônica e dinâmica das populações de Cladocera em três lagoas marginais, na região de transição Rio Paranapanema - Represa de Jurumirim - SP
• Beneficiário: Eliana Aparecida Panarelli
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 97/04999-8 - Biodiversidade, estrutura das comunidades e processos ecológicos na zona de ecótono rio/lago: um estudo na região de desembocadura do rio Paranapanema na represa de Jurumirim
• Beneficiário: Raoul Henry
• Modalidade de apoio: Auxílio à Pesquisa - Temático