O fitoplâncton como discriminador ambiental dos reservatórios do Sistema Cantareira (SP)
Carregando...
Arquivos
Data
2016-05-09
Autores
Santos, Larissa Gonçalves [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Sistema Cantareira é um multissistema responsável pelo abastecimento de aproximadamente 55% da população da região metropolitana de São Paulo, atuando diretamente no desenvolvimento econômico e regional. Devido aos diversos tipos de impactos gerados pelas ações antrópicas, o processo denominado de eutrofização, contribui para o aumento da degradação e perda da qualidade da água. Contudo, estudos através da identificação do fitoplanctôn pelos traços funcionais têm contribuído cada vez mais dentro da ecologia, principalmente como ferramenta bioindicadora no monitoramento dos ecossistemas aquáticos. Dessa forma, essa pesquisa tem como objetivo principal caracterizar e comparar sazonalmente as massas de água, do ponto de vista do estado trófico e verificar se há uma distribuição espacial horizontal da comunidade fitoplanctônica ao longo de um eixo longitudinal em cada reservatório e entre os reservatórios utilizando o fitoplâncton como ferramenta de predição ambiental. As coletas foram realizadas em maio/junho (período seco) e em novembro/dezembro (período chuvoso) no ano de 2013, nos reservatórios Jaguari-Jacareí, Cachoeira, Atibainha e Paiva Castro. As análises incluíram variáveis físicas, químicas e clorofila-a da água, bem como análises qualitativas e quantitativas da comunidade fitoplanctônica. Em relação ao estado trófico o reservatório Jaguari nos dois períodos de coleta apresentou alto grau de trofia, exibindo maiores sinais de degradação da qualidade da água, com elevados teores de nitrato, amônio e clorofila-a, no sentido rio/barragem, oscilando de supereutrófico a mesotrófico, e os reservatórios a jusante variaram de mesotrófico a oligotrófico. Foi registrado 252 táxons, distribuídos em 15 classes taxonômicas, sendo as classes Chlorophyceae, Cyanophyceae e Bacillariophyceae, as que mais contribuíram para a riqueza, nos dois períodos de coleta. A densidade algal máxima ocorreu no período chuvoso, com maiores valores no reservatório Jaguari (3.860,970 ind.ml-1) e com maior abundância da classe Cyanophyceae (2.966,832 ind.ml-1), porém os menores valores ocorreram no Paiva Castro (212.208 ind.ml-1). O reservatório Atibainha (ponto rio), no período chuvoso, registrou alta diversidade e baixa dominância, já o reservatório Jaguari (barragem) no período seco, apresentou baixa diversidade e alta dominância da espécie invasora Ceratium furcoides. Através da análise de cluster (presença/ausência), observou-se a divisão de dois grandes grupos e pelo índice de Jaccard verificou-se que as comunidade são taxonomicamente diferentes. As maiores contribuições da biomassa foi no reservatório Jaguari nos dois períodos sazonais, sendo que na seca a espécie Ceratium furcoides foi a que mais contribuíu sobre a biomassa específica e no período chuvoso foi a espécie Aphanizomenon gracile. Com análise de similaridade (ANOSIM) foi possível verificar a heterogeneidade na escala espacial e sazonal, comprovando uma diferença significativa na composição de espécies entre os períodos e entre os reservatórios. E através das análises de correspondência canônica, observou-se que tanto as classes taxonômicas, grupos funcionais segundo Reynolds et al. (2002)/ Padisák et al. (2009) e grupos funcionais baseado na morfologia segundo Kruk et al. (2010), relacionaram-se significativamente entre as variáveis ambientais, apresentando um gradiente longitudinal entre os reservatórios em relação a trofia. Conclui-se que por mais que os agrupamentos taxonômicos e funcionais são ótimas ferramentas para o biomonitoramento, ainda é necessário a utilização de outros meios para complementar de forma eficiente um contínuo monitoramento desses reservatórios e aplicar de forma adequada planos de manejos sustentáveis para uma melhor gestão das bacias hidrográficas.
Cantareira System is a multi-system responsible for supplying approximately 55% of the population of the metropolitan region of São Paulo, acting directly in the economic and regional development. Due to the different types of impacts of human activities, the process called eutrophication, contribute to increased degradation and loss of water quality. However, studies by identifying the phytoplankton by functional traits has contributed increasingly in ecology, mainly as a bioindicator tool in monitoring of aquatic ecosystems. Thus, this research aims to characterize and seasonally compare the water bodies, from the point of view of the trophic state and check for horizontal spatial distribution of phytoplankton along a longitudinal axis in each reservoir and from the reservoir using phytoplankton as environmental prediction tool. Samples were collected in May/June (dry season) and in November/December (rainy season) in 2013, in Jaguari-Jacarei reservoirs, Cachoeira, Atibainha and Paiva Castro. The analysis included physical, chemical and chlorophyll to the water, as well as qualitative and quantitative analysis of the phytoplankton community. In relation to trophic state the Jaguari reservoir in the two collection periods presented high degree of hypertrophy, showing major signs of degradation of water quality, with high levels of nitrate, ammonium and chlorophyll-a, towards the river/dam, ranging from super eutrophic to mesotrophic and downstream reservoirs ranged from mesotrophic to oligotrophic. Was recorded 252 taxa, distributed in 15 taxonomic classes, and the classes Chlorophyceae, Cyanobacteria and Bacillariophyceae, contributed the most to wealth, the two collection periods. The maximum algal density occurred in the rainy season, with higher values in Jaguari reservoir (3.860.970 ind.ml-1) and greater abundance of cyanobacteria class (2.966.832 ind.ml-1), but smaller values occurred in the Paiva Castro (212.207 ind.ml-1). The Atibainha reservoir (river point) in the rainy season, recorded high diversity and low dominance, since the Jaguari reservoir (dam) in the dry season, showed low diversity and high dominance of invasive Ceratium furcoides species. Through cluster analysis (presence / absence), there was the division of two groups and the Jaccard index was found that the community are taxonomically different. The major contributions of biomass was in Jaguari reservoir in two seasonal periods, and in the dry species Ceratium furcoides was the most contributed on the specific biomass and the rainy season was the species Aphanizomenon gracile. By similarity analysis (ANOSIM) observed heterogeneity in spatial and seasonal scale, showing a significant difference in species composition between periods and between the reservoirs. And through canonical correlation analysis, it was observed that both the taxonomic class, functional groups according to Reynolds et al. (2002)/Padisák et al. (2009) and functional groups based on morphology second Kruk et al. (2010), related significantly between environmental variables, with a longitudinal gradient between the reservoirs in relation to trophic. It is concluded that while the taxonomic and functional grouping are great tools for biomonitoring, one is still required use of other means to complement efficiently a continuous monitoring of these reservoirs and to adequately apply sustainable management plans for better management watershed.
Cantareira System is a multi-system responsible for supplying approximately 55% of the population of the metropolitan region of São Paulo, acting directly in the economic and regional development. Due to the different types of impacts of human activities, the process called eutrophication, contribute to increased degradation and loss of water quality. However, studies by identifying the phytoplankton by functional traits has contributed increasingly in ecology, mainly as a bioindicator tool in monitoring of aquatic ecosystems. Thus, this research aims to characterize and seasonally compare the water bodies, from the point of view of the trophic state and check for horizontal spatial distribution of phytoplankton along a longitudinal axis in each reservoir and from the reservoir using phytoplankton as environmental prediction tool. Samples were collected in May/June (dry season) and in November/December (rainy season) in 2013, in Jaguari-Jacarei reservoirs, Cachoeira, Atibainha and Paiva Castro. The analysis included physical, chemical and chlorophyll to the water, as well as qualitative and quantitative analysis of the phytoplankton community. In relation to trophic state the Jaguari reservoir in the two collection periods presented high degree of hypertrophy, showing major signs of degradation of water quality, with high levels of nitrate, ammonium and chlorophyll-a, towards the river/dam, ranging from super eutrophic to mesotrophic and downstream reservoirs ranged from mesotrophic to oligotrophic. Was recorded 252 taxa, distributed in 15 taxonomic classes, and the classes Chlorophyceae, Cyanobacteria and Bacillariophyceae, contributed the most to wealth, the two collection periods. The maximum algal density occurred in the rainy season, with higher values in Jaguari reservoir (3.860.970 ind.ml-1) and greater abundance of cyanobacteria class (2.966.832 ind.ml-1), but smaller values occurred in the Paiva Castro (212.207 ind.ml-1). The Atibainha reservoir (river point) in the rainy season, recorded high diversity and low dominance, since the Jaguari reservoir (dam) in the dry season, showed low diversity and high dominance of invasive Ceratium furcoides species. Through cluster analysis (presence / absence), there was the division of two groups and the Jaccard index was found that the community are taxonomically different. The major contributions of biomass was in Jaguari reservoir in two seasonal periods, and in the dry species Ceratium furcoides was the most contributed on the specific biomass and the rainy season was the species Aphanizomenon gracile. By similarity analysis (ANOSIM) observed heterogeneity in spatial and seasonal scale, showing a significant difference in species composition between periods and between the reservoirs. And through canonical correlation analysis, it was observed that both the taxonomic class, functional groups according to Reynolds et al. (2002)/Padisák et al. (2009) and functional groups based on morphology second Kruk et al. (2010), related significantly between environmental variables, with a longitudinal gradient between the reservoirs in relation to trophic. It is concluded that while the taxonomic and functional grouping are great tools for biomonitoring, one is still required use of other means to complement efficiently a continuous monitoring of these reservoirs and to adequately apply sustainable management plans for better management watershed.
Descrição
Palavras-chave
Fitoplâncton, Estado trófico, Grupos funcionais, Reservatórios, Phytoplankton, Trophic state, Functional groups, Reservoirs