The community structure of benthic macroinvertebrates in the inner branches of Estero Salado estuary and Guayas river in Ecuador

Estuarine ecosystems and watersheds have suffered significant changes in its structure and functioning due to human activities as pollution generated by discharges of domestic and industrial wastewater. This study was conducted on water and sediments samples from the basin of Guayas River and the inner branches of Estero Salado (ES) in Guayaquil city, Ecuador during the period 2007 to 2012 in different phases. In this research were evaluated the relationship between several organic and inorganic pollutants as Total Petroleum Hydrocarbon (TPH), most toxic heavy metals (Pb, Hg. And Cd) and environmental parameters that may influence the invertebrate community structure in Protected and Urban Areas in superficial sediments of branches of Estero Salado. This survey contributes to knowledge of variation of polluted agentsover space and time in estuarine sediments. To determine firstthe composition, abundance and diversity of macroinvertebrates in 43 water bodies in the Guayas province and evaluate thewater quality by use the bioticindex as(BMWP /Col).To determine changes in the macrobenthic community before and during the bioremediation process in sediments polluted by hydrocarbon in ES.To assess the feasibility of recolonization of benthic macroinvertebrates in artificial substrate on polluted areas in inner branches of ES. The main results showed that 72% of sites surveyed in the Guayas Basin are very polluted by organic matter, four different assemblages were detected in the subwatershed, 84 genera were identified, the most abundance specie wasMelanoides cf tuberculata, this and othersexotic specieswere registered such as Pomacea canaliculata and Corbicula cf fluminea. The highest diversity occurred in Bucay, El Triunfo, Simon Bolívar and Chongón counties, places being near of foothills of Coordillera Occidental de Los Andes and Chongón Colonche. The community structure of benthic macroinvertebrates in inner branches of Estero Salado is different along the time and space, the results of this research suggest a significant change in biotic ensemble in Urban Areas where decrease the diversity of native macroinvertebrates and proliferate opportunistic species have replaced characteristic species due to the physical and chemical alteration of the water column and sediment being some of the variables that significantly influence in this change were low salinities (0 psu), decrease of dissolved oxygen concentration (0 mg/L), high level of Total Petroleum Hydrocarbons (145872.7 mg/kg) and heavy metals especially lead (66.54 mg/Kg). This project aimed to develop restoration techniques as bioremediation of hydrocarbon sediment and determined that use of native bacterial consortia of ES did not affect macrobenthic communities and could be an efficient technique if there is removal of pressures and imposed on this habitat. Artificial substrate can increase the native bivalve populations in polluted area in ES.The results of this research have implications for management strategies, conservation and ecological restoration.Besides showed the role the Protected Area as Reserva de Producción Faunística Manglares El Salado as nucleus area in the conservation of few fragments of this emblematic estuarine ecosystem in Ecuado

Participação da Embrapa Solos em congressos: ano 2009.

bitstream/CNPS-2010/14826/1/doc119-2009-resumos-congressos.pd