Grupos funcionais fitoplanctônicos sob diferentes níveis de nutrientes: efeitos da piscicultura em abordagem experimental

• Ano de defesa: 2011
• Autor(a) principal: Cruz, Patrícia Silva
• Orientador(a): Ceballos, Beatriz Suzana Ovruski de
• Banca de defesa: Sousa, José Tavares de , Barbosa, Luciana Gomes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual da Paraíba
• Programa de Pós-Graduação: Mestrado em Ciência e Tecnologia Ambiental - MCTA
• Departamento: Tecnologia Ambiental
• País: BR
• Palavras-chave em Português: Mesocosmos; Grupos funcionais fitoplanctônicos; Piscicultura; Alterações histológicas
• Palavras-chave em Inglês: Mesocosms; Light limitation; Functional phytoplankton groups; Pisciculture; Histological alterations.
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA
• Link de acesso: http://tede.bc.uepb.edu.br/tede/jspui/handle/tede/1717

The high population growth around watershed areas, mainly from supply, has led aquatic ecosystems to show high contamination levels, mainly because the increasing of nitrogen and phosphorus availability. This study aims to elucidate how the impact of nutrients addition (phosphorus and nitrogen), from the pisciculture contribution, has interfered in the composition and in the dynamic of the functional phytoplankton groups and fish respiratory and digestive system. In this context, the functional groups applicability as descriptors of shallow eutrophic ecosystems with pisciculture activity is approached. The study was carried out from January to May 2010, with samplings carried out in fortnightly intervals at the subsurface. The abiotic variables which were obtained: temperature, water transparency, euphotic zone, electric conductivity, dissolved oxygen, pH, n-ammoniacal, nitrate, nitrite, total phosphorus, soluble reactive phosphorus. The functional groups have been grouped based in the ecological/adaptive features. In general, the variation of light availability has been one of the main attributes related to changes in the planktonic algae composition in the different used treatments. The phytoplankton associations which have been identified were typical from eutrophic shallow environments and the strategies CRS have registered a predominance of R strategists, generally associated to environments with light limitation. As a response to the alterations which have occurred at the mesoenvironments, it has been evidenced in the fish intestine and gills the presence of parasites, which were favored by the storage and decay in the water quality, killing some fish copies by asphyxia and also by the hepatocytes massive death (hepatic failure), due to high contribution of N and P from fertilizations, feeding, from the fish metabolism and from its release in the water column because the organic matter degradation of the dead organisms, including algae.