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Universidade Estadual da Paraíba (2013)

Macroinvertebrados bentônicos como indicadores de qualidade ambiental em reservatórios na região semiárida

AZEVEDO, Evaldo de Lira

Titre : Macroinvertebrados bentônicos como indicadores de qualidade ambiental em reservatórios na região semiárida

Auteur : AZEVEDO, Evaldo de Lira

Université de soutenance : Universidade Estadual da Paraíba

Grade : Mestre em Ecologia e Conservacao 2013

Reservoirs are ecosystems subjected to anthropogenic pressures, particularly, brought about by the benefits that these environments can provide. The loss of biodiversity is one of the reasons that leads to reduction of the environmental quality of these aquatic ecosystems. For the assessment of environmental quality samplings were performed 60 in three reservoirs located in the Paraíba River basin in december 2011 ; Argemiro de Figueiredo, Epitácio Pessoa and Poções . This dissertation consists of two chapters, the first being for the first record of the exotic clam Corbicula largilliet (Philippi, 1844) in the Rio Paraiba, and second on the evaluation of the environmental quality of reservoirs in semiarid region using the community benthic macroinvertebrates as bioindicators. In the first chapter, was recorded the exotic clam Corbicula largilliet reservoir Epitácio Pessoa (Boqueirão), located in the middle course of the Rio Paraiba, municipality of Boqueirão-PB. This is a freshwater bivalve family Corbiculidae (Bivalvia, Heterodonta, Veneroida) of Asian origin and endemic Lakes system of the Yangtze Kiang in China who invaded different regions in South America and can damage the local biota. In this context, implementation of the river São Francisco, in addition to thicken populations of exotic species existing in the Paraíba River basin as Melanoides tuberculatus (Müller, 1774) and Corbicula largilliet, can facilitate the introduction of other exotic species, such as mollusk Limnoperma fortunei (Dunker 1857). This fact highlights the need for further studies considering the introduction of aquatic species in the semiarid region of Brazil. The second manuscript was to evaluate the environmental quality of reservoirs in semiarid region using metrics disorder, physical and chemical parameters of the water and benthic macroinvertebrate community as an indicator. We collected water samples, benthic macroinvertebrates and held the application of 600 evaluation protocols of physical habitats in 60 sampling sites. The implementation of the protocol aimed to collect data from human influence, for subsequent calculation of metrics anthropogenic disturbance of the riparian zone and flood zone of the reservoirs. The metrics disorder were significantly different (PERMANOVA : pseudo-F1, 59 = 86.65, p = 0.001) among the sampling sites. Data of physical and chemical variables in water were grouped according to the metrics of anthropogenic disorder, showing significant difference between the sampling points (p <0.05). We collected 11,145 bodies distributed in 23 taxa. When considering all taxa community no significant difference between the sampling sites (p> 0.05). Thus, for statistical analysis considered only the fauna of Chironomidae (Diptera, Insecta), having been identified to genus level and have shown significant difference (PERMANOVA : Peseudo-F1, 59 = 3.5916, P = 0.005) among the sampling sites. The exotic mollusk Melanoides tuberculatus showed high densities in both groups formed by disturbance metrics anthropogenic disturbance. The analysis of the metrics of human disturbance, physical and chemical variables and genera of Chironomidae (Diptera, Insecta), separated the sampling sites into two groups, group 1, local environmental quality and group 2, with lower local environmental quality. The genera of Chironomidae Goeldichironomus in lower density, and Aedokritus Fissimentum indicated better environmental quality, while gender Goeldichironomus, Chironomus, and Coelotanypus in higher densities, indicated places with lower environmental quality. Most sampling locations classified as having good environmental quality occurred in the reservoir Argemiro de Figueiredo. The improved environmental quality in this reservoir is due to limited occupancy of its banks, which are very steep, which hinders the development of human activities. The reservoirs Epitácio Pessoa and Poções have extensive occupation of its banks, which meant that most of the sampling sites located in these reservoirs were classified as having poor environmental quality. The results show the need to take measures to conserve these ecosystems, the data generated can be used for conservation and management measures for the maintenance of ecological services provided by these reservoirs.

Mots clés : Qualidade ambiental Qualidade da água Ecossistema aquático Rio São Francisco


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