Variação espaço-temporal de Rotifera em um reservatório eutrofizado no sul do Brasil

Abstract

ABSTRACT. Spatial-temporal variation of Rotifera in an eutrophic reservoir in southern Brazil. We analyzed the spatial and temporal variation of rotifers in a small, shallow and eutrophic reservoir, with intense Cyanobacteria blooms, in seven sampling stations during 17 months (March/2002 to July/2003. Fifty-two taxa were identified, comprising 16 families. Brachionidae, Conochilidae, Synchaetidae, Lecanidae, Collothecidae, Trichocercidae, and Gastropodidae were the most commonly found. Collotheca sp. was abundant in the winter (dry period), while numbers of Conochilus coenobasis and Keratella cochlearis were low. The abundance of Brachionus mirus var. reductus, Filinia longiseta and Keratella lenzi peaked in the summer (rainy season), while for Kellicottia bostonensis, Ploesoma truncatum, Polyarthra remata, Polyarthra vulgaris and Ptygura sp., abundance was highest in the winter, mainly associated with atypical rainfall. Significant differences in the number of taxa and abundance of rotifers were observed during the sampling period. The canonical correspondence analysis explained 46% of the relationship between rotifer abundance and environmental variables, positively correlated with rainfall, nitrite, water temperature, organic nitrogen, nitrate and air temperature. Variations in rotifer abundance were observed a month after changes in the phytoplankton community. Taxa, such as Filinia longiseta, Keratella lenzi and Keratella cochlearis, showed a temporal variation similar to that of other eutrophic reservoirs, while the heterogeneous distribution pattern observed in most taxa could be due to the hydrodynamics of the recently built reservoir and the adverse climatic conditions. KEYWORDS.Water supply, eutrophication, Cyanobacteria. RESUMO.A variação espacial e temporal de rotíferos foi analisada em um reservatório pequeno, raso e eutrófico, com intensas florações de algas Cyanobacteria, em sete pontos de amostragem durante 17 meses (março/2002 a julho/2003). Foram identificados 52 táxons em 16 famílias, sendo Brachionidade, Conochilidae, Synchaetidae, Lecanidae, Collothecidae, Trichocercidae e Gastropodidae as mais frequentes. Collotheca sp. foi abundante no inverno (período seco), enquanto Conochilus coenobasis Skorikov, 1914 e Keratella cochlearis Gosse, 1851 apresentaram baixas abundâncias. Brachionus mirus var. reductus (Koste, 1972), Filinia longiseta (Ehrenberg, 1834) e Keratella lenzi (Hauer, 1953) apresentaram picos de abundância no verão (período chuvoso), e Kellicottia bostonensis (Rousselet, 1908), Ploesoma truncatum (Levander, 1894), Polyarthra remata (Skorikov, 1896), Polyarthra vulgaris Carlin, 1943 e Ptygura sp. no inverno, entretanto, relacionados a chuvas atípicas. Diferenças significativas do número de táxons e da abundância total dos rotíferos ocorreram entre os meses amostrados. A análise de correspondência canônica explicou 46% da relação da abundância dos rotíferos e variáveis ambientais, correlacionados com a pluviosidade, nitrito, temperatura da água, nitrogênio orgânico, nitrato e temp...

Reservoir Eutrophication: Preventive Management: An applied example of Integrated Basin Management Interdisciplinary Research

“…The number of species found was similar to that found in the Paraibuna and Guarapiranga Reservoirs, both located in the Southeast region of the country (CABIAN-CA, 1991;CALLEFI, 1994), and in the Iraí Reservoir, in the hydrographic basin of the Iguaçu River (SERAFIM-JUNIOR, et al 2005). The number of species found was similar to that found in the Paraibuna and Guarapiranga Reservoirs, both located in the Southeast region of the country (CABIAN-CA, 1991;CALLEFI, 1994), and in the Iraí Reservoir, in the hydrographic basin of the Iguaçu River (SERAFIM-JUNIOR, et al 2005).…”

“…The zooplankton species that were recorded with high frequency and in abundance in the Rio Verde Reservoir were also recorded in other Brazilian reservoirs and are characteristic of oligo-mesotrophic environments (SENDA-CZ, 1999;NOGUEIRA, 2001;SERAFIM-JUNIOR et al, 2005;LANSAC-TÔHA et al, 2005). For the rotifers, Matsumura-- Tundisi et al (1990) proposed the association of P. vulgaris and K. Tropica as indicators of less eutrophic environments and C. unicornis and K. cochlearis as characteristic of more eutrophic environments.…”

Spatial Distribution of Zooplankton Diversity across Temporary Pools in a Semiarid Intermittent River

“…It is likely that the opposite relationship observed in the Santana reach is related with the greater human impact that this reach suffers in comparison with the others, since it receives organic inputs from local human communities and from an adjacent intermittent tributary that receives waste water from a nearby town. This probably resulted in the observed high abundance of species that are indicative of eutrophic environments such as the genus Brachionus [59] and specially Brachionus angularis and B. havanaensis [60].…”

Zooplâncton (Rotifera, Cladocera E Copepoda) E a Eutrofização Em Reservatórios Do Nordeste Brasileiro

“…Alguns autores afirmam que a competição, a predação, temperatura, a qualidade e disponibilidade de nutrientes são as variáveis que mais influenciam na heterogeneidade desses organismos. Tais fatores físico-químicos e biológicos podem atuar concomitantemente ou interagir em diferentes situações (Sampaio et al 2002, Perbiche-Neves et al 2007, Ghidini et al 2009, Serafim-Júnior et al 2010.…”