Environmental reconstruction of a coastal lagoon: a case study of Itapeva Lagoon (RS)

Abstract

The Itapeva Lagoon is an elongated water body, parallel to the shoreline, with an area of approximately 124 km2. This coastal environment, located at 29º30'S and 40º49'W, at the coast of Rio Grande do Sul state, between the cities Torres, Dom Pedro de Alcântara, Três Cachoeiras, Arroio do Sal and Terra de Areia is the study area of this project, which has the objective to determinate elements levels: As, Cd, Cr, Cu, Ni, P, Pb, Sc and Zn, in sediment cores collected in the region. Furthermore, it will be calculated indices of sediment contamination: contamination factor, enrichment factor and pollution load index (PLI), beyond the relation of the values of recent geochronology. Most of the Brazilian population lives at the coastal zone, which increases the anthropogenic pressure over these areas and with this, the importance of studies at those regions. From previous works, it is possible to notice the importance of heavy metals concentrations in water bodies, as to the survey of environmental data to understanding the process of anthropic alteration, specially in areas next to cities, where they use water for domestic use, agriculture and industries purposes. The tendency around the Itapeva Lagoon is the increase of the population density (inhab/km2) and the enhancement of residues discharged from industries and from population centers, besides the natural environment alteration due to anthropic activities (construction of houses, enterprises, barriers, etc.). In order to realize this project, it will be performed the analysis of the elements of interest using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP OES), the granulometry determination, biodetritic carbonate content, total carbon and total nitrogen. Through this detailed study, with the environmental reconstruction of the lagoon with the parameters listed before, it will be possible to know the anthropogenic degree of Itapeva Lagoon.