Estimation of Submerged Aquatic Vegetation Height and Distribution in Nova Avanhandava Reservoir (São Paulo State, Brazil) Using Bio-Optical Modeling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The climatic rhythm and blooms of cyanobacteria in a tropical reservoir in São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecological carrying capacity for intensive tilapia (Oreochromis niloticus) cage aquaculture in a large hydroelectrical reservoir in Southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Changes in the phytoplankton structure downstream a large reservoir: effects of tributaries on the assemblages attributes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coupling remote sensing bio-optical and three-dimensional hydrodynamic modeling to study the phytoplankton dynamics in a tropical hydroelectric reservoir

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Muller, 1774) in a Neotropical reservoir?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Importance of reservoir tributaries to spawning of migratory fish in the upper parana river

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Does the plankton community follow the horizontal water quality heterogeneity in a tropical urban reservoir (Guarapiranga reservoir, Sao Paulo, Brazil)?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ectoparasites of Nile tilapia (Oreochromis niloticus) in cage farming in a hydroelectric reservoir in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of summertime mesoscale convective systems on the heat balance and surface mixed layer dynamics of a large Amazonian hydroelectric reservoir

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Change detection as support for monitoring the dynamic of land around reservoir

The change detection technique was used in this study to provide preliminary information on the dynamics of land cover in the region over the western basin of the Tiete River. This area is characterized by sequence of reservoirs and intense agricultural activity, triggering series negative effects. One of the impacts is contamination and proliferation of aquatic organisms in these aquatics environments, increased by release of nutrients from human activities. This work was possible to observe a large switching classes and secondary vegetation bare land, probably related to agricultural activity.

Popularion biology of abdominant fish species of the Santa Bárbara river, a tributary of the Nova Avanhandava reservoir (low Tietê river, São Paulo State, Brazil)

The aim of this study is to characterize some population biology parameters of P. squamosissimus, A. altiparanae and S. maculatus, the dominant fish species of the Santa Bárbara river, a tributary of the Nova Avanhandava reservoir, low Tietê river. Fish samplings were performed monthly between September/2002 and August/2003, using gill nets with different mesh sizes. Females of all species have larger standard lengths than males (Mann-Whitney, p < 0.0001), and are more frequent in superior size classes (Kolmogorov-Smirnov, p < 0.0001). All populations presented isometric growth, but differences between males and females were observed. Only P. squamosissimus presented a gender ratio different from 1:1, with a higher proportion of males (1:2, X2, p < 0.05). The onset of gonadal maturation occurs at 15 cm in P. squamosissimus, 9 cm in S. maculatus and at 8.9 cm in A. altiparanae. In all species populations, the adults predominate over juveniles. The allometric condition factor (K) of P. squamosissimus and S. maculatus presented higher values in the periods from March-May and June-August, and A. altiparanae in the period from March-May (Kruskal-Wallis, p < 0.05). These results indicate that the populations successfully exploit the lentic environment, and present life cycle tactics adapted to their particular means of environment occupation.

Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, southeastern Brazil

In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures) among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.