Fatores estruturantes das comunidades de invertebrados planctônicos e bentônicos como ferramenta para o biomonitoramento de reservatórios no semiárido

• Ano de defesa: 2013
• Autor(a) principal: Azevêdo, Daniele Jovem da Silva
• Orientador(a): Barbosa, José Etham de Lucena
• Banca de defesa: Pereira, Marcos Callisto de Faria , Marques, João Carlos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual da Paraíba
• Programa de Pós-Graduação: Mestrado em Ecologia e Conservação
• Departamento: Ecologia e Conservação
• País: BR
• Palavras-chave em Português: Biomonitoramento; Ecologia; Ecossistemas aquáticos
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA
• Link de acesso: http://tede.bc.uepb.edu.br/tede/jspui/handle/tede/2109

The extensive degradation on freshwater ecosystems has led to the development of tools for monitoring and actions mitigation of impacts. The tools based on biological indicators have been widely developed and applied, as it allows greater accuracy in obtaining the actual picture of the ecological quality of the ecosystem, when compared to traditional methods. Thus, the goal of this dissertation is to establish, among the factors structuring (abundance, richness, diversity and biomass) communities of planktonic and benthic invertebrates, which could compose biomonitoring tool for the ecological quality of the reservoirs in the semiarid region. For this were: i) analyzed aspects of abundance, richness, diversity and biomass of planktonic and benthic invertebrates ii) drivers related factors (physical, chemical and biological) for each of the structural aspects evaluated iii) identified the response each structural aspect (abundance, richness, diversity and biomass) in relation to environmental factors tested, reflects the ecological condition of the ecosystem and iv) related factors structuring which could be used as a tool for biomonitoring of reservoirs inserted in semi-arid climate. Our hypothesis is that the biomass among the factors structuring (abundance and diversity) of invertebrate communities is the best biological indicator for assessing the quality of reservoirs in the semiarid region, in view of sensitivity to variables related to anthropogenic influences (loading nutrient) composition and physical structure of the habitat. Data were collected in the reservoir and Poções and Camalaú, both located on the upper course of the river Paraíba, Paraíba, Brazil. Samplings were made fortnightly in two hydrological periods in 2012: April (dry season in the region) and June (rainy season in the region). In each shell collections occurred in two seasons, being: Station 1 - near the entrance of the main tributary (Paraíba river) and Station 2 - next to dam of the reservoir and, at each station, samples were collected from water, sediment and submerged plants to compose the set of environmental variables, in addition to performing the experiment in the primary productivity of phytoplankton as biological variable. Zooplankton samples were collected by filtering 25 liters of water, plankton net, and macroinvertebrate samples were obtained from the collection of the sediment with the assistance collector Ekman-Birge. The data set shows that the distribution of abundance, richness, diversity and biomass of planktonic communities and benthic invertebrates occur similarly front environmental variables, but that there are different patterns of distribution of structural features between the reservoirs Poções and Camalaú, between limnetic and littoral zone and between the dry and rainy periods, so as that the environmental variables acting on spatial scale (between reservoirs), the compartments of reservoirs (littoral and pelagic) and seasonal scale (period of lesser and greater volume the reservoirs), suggesting that the tools for biomonitoring of these bodies of water these scales of variation. The structure of zooplankton was most often associated with variables related to human impacts indication (such as high concentrations of phosphorus, nitrogen and high rates of phytoplankton primary productivity), while the structure of macroinvertebrates was significantly associated with the structure factor of the habitat (as sediment composition and presence of the submerged plants), this shows that communities of planktonic and benthic invertebrates exhibit sensitivity to environmental factors differentiated, with complementary information and thus monitoring programs reservoirs in the semiarid should include both communities for greater accuracy in assessing the ecological quality of water bodies. For both invertebrate communities, the diversity showed not to be a good attribute to be used individually as a tool for evaluating these water bodies, whereas in environments where there are dominant species, this factor is strongly influenced. The abundance, if used in isolation as a biological indicator, can lead to different conclusions for classification of ecological quality, it can reflect the plasticity of generalist species. The biomass was a good tool for biomonitoring in reservoirs, considering that for both invertebrate communities that the control variables the aspect structuring are variables related to trophic state of the ecosystem and with the physical structure of the habitat, which allows inferred areas subject to degradation and conservation priority areas in the watershed of the river Paraíba. The results also show that in biomonitoring programs for semi -arid reservoirs must be considered variables, such to: total phosphorus, total nitrogen, chlorophyll a, dissolved oxygen, dissolved oxygen% and elements related to habitat structure, since the referent set of variables was associated with the distribution pattern of abundance, richness, diversity and biomass of invertebrate communities during the study period.