Fish parasites and biomarkers as tool for evaluation pollution level in rivers and reservoirs at Tietê River, São Paulo State

Abstract

Fish parasites have attracted the interest of ecologists of parasitism as a potential bioindicator of ecosystem integrity, due to a variety of ways in which they respond to anthropogenic pollution. In addition to parasites, biomarkers of exposure in fish have also become important tools in ecotoxicological studies. Recently studies of ecotoxicology and parasitology have integrated environmental information about parasitism and biomarkers to understand the effect of water pollution at various levels of biological organization, ranging from the effect on the enzymatic mechanism in fish until on parasites community. The scope of this study is to assess the communities of parasites and biomarkers of two fish species (Steindachnerina insculpta and Geophagus brasiliensis) as bioindicators of environmental pollution in rivers and reservoirs of the Tietê River basin (medium / low Tietê). Fish will be collected in three reservoirs with different degrees of pollution (High = Bariri, Intermediate = Barra Bonita, Low = Promissão) during four season in year. The collection points are distributed in the tributaries rivers (n = 3) and the main channel (n = 3) of each dam/reservoir, totalizing 18 collection points. After the fish collected with nets will be kept alive until the time of necropsy, where the liver will be removed, put in aluminum foil properly identified and held in a gallon portable of liquid nitrogen (-196>C) to determine the enzymatic activity of CYP1A in the laboratory. After removal of the liver, the fish will be individualized in plastic bags and frozen for parasitological analysis in the Laboratory of Parasitology of Wild Animals (LAPAS), Department of Parasitology, UNESP. Thus, the project seeks to understand the relationship between pollution / parasitism / biomarkers and to establish a protocol with these species of fish for the design of future monitoring programs of environmental quality in the basin of the Tiete River, Sao Paulo State. (AU)