Knowledge of fish parasitic fauna and its use in the water resource management and environmental impact process

Abstract

Estuarine environments are places of high productivity and diversity. The different profiles presented by these regions allow the fixation of many organisms, which will be exposed to the high chemical and physical variability present in the estuaries. In the surroundings of most Brazilian estuaries, many human groups have been established for many years, promoting the most diverse types of environmental degradation. In addition to the state capital of Alagoas, other municipalities grew around the Mundaú and Manguaba lagoon, which are directly linked to the sea, being typically estuarine environments. The decrease in fish stocks in the region is remarkable, with the disappearance of some species. In addition, the traditional population that depends on fish for their livelihoods is in danger of consuming toxic elements from various industries, untreated sewage, and all the waste that is carried into the ponds and their tributaries, as such pollutants can be accumulated along the food chain. To determine the biological levels of pollutants in the environment, bioindicators and bioaccumulators have been used, together with the physicochemical analyzes of water and sediments, which mainly describe the total concentrations of the respective pollutants in the environment. Fish parasites have been considered as good accumulation bioindicators, as environmental pollution significantly affects their distribution and pathogenicity. Thus, this work aims to use the parasites of the dominant fish species in the Estuarine-Lagunar-Mundaú-Manguaba Complex as possible bioindicators of environmental contamination. For this, host collections will occur in the rainy and dry periods, to observe if there was a difference in parasitic communities, considering that rainwater further changes the dynamics of the lagoons. The parasites will be collected, identified, and both these and tissue samples of their host fish will be analyzed for their ability to bioaccumulate certain elements, especially metals. The expected results will contribute to increasing the knowledge about bioaccumulative processes of pollutants in the aquatic environment, as well as to obtain information on the diversity of parasitic organisms in the region since studies involving this theme are scarce. (AU)