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Ecotoxicological tests are intended to assess effects that chemical substances or industrial effluents may have on the environment. Pursuant to Prósperi and Bertoletti (2004), an advantage of using such tests in assessing potential impacts to the coastal region is associated with toxic results, which usually indicate chemical contamination and may, therefore, be used as assessment mechanisms with an ample spectrum of effects. Algae are used in ecotoxicological tests due to their sensitivity to changes in the environment and to their relatively brief life cycle, which makes it possible to assess toxic effects over several generations (COSTA et al, 2008). Tests with sea urchins have been used to assess the chronic ecotoxicity of effluents, when they are disposed in a marine environment. Marine sediments may be deposits for persistent pollutants disposed in the water environment (MELO and ABESSA, 2002) and, then, may be converted into more enriched deposits when compared to the water column (FURLEY, 2006). Studies that address the effect of contaminants on a number of benthic species evidence that copepods are susceptible to the effects of several compounds (COULL and CHANDLER, 1992). This study is intended to assess water and sediment quality in the region of Praia Mole, with the use of ecotoxicological tests in different environmental matrices.

The study area covers the continental platform of the State of Espírito Santo, the region of Praia Mole and Carapebus beach. The collections were during the Autumn and Spring of 2013, in 12 sampling locations. The water samples were collected with a Van Dorn sampler at 50 cm from the surface and 50 cm from the bottom, while the sediment samples were collected with a Petersen-type bottom sampler. Material was collected in accordance with the procedures established in the Standard ABNT NBR 15469 (2007). For the tests, the organisms Skeletonema costatum, Echinometra lucunter and Nitokrasp. were used in surface water matrices, seabed water, and marine sediment, respectively. The methodologies complied with the Standards ISO 10253 (2006), ABNT-NBR 15350(2012), and the method proposed by Lotufo and Abessa (2002). In parallel, chemical analyses were held for parameters: BOD, Turbidity, Total Suspension Solids, Total Fluoride, Total Ammonium Nitrogen, Nitrite, Nitrate, Total Phosphorus, Total Iron, Dissolved Iron, Total Manganese, Dissolved Manganese, Total Aluminum, Dissolved Aluminum, Dissolved Zinc, Total Zinc, Total Cyanide, Total Phenols, Dissolved Lead, Total Lead, Total Copper and Dissolved Copper, based on Standard Methods (2012).

Effects were evidenced in three samples of surface water collected in the Autumn of 2013. They contained fluoride values above the limit established by CONAMA Resolution 357/2005. On the other hand, the result of seabed water analysis using E. lucunter evidenced ecotoxicity in only one location, from Autumn of 2013, yet no chronic effect to the organism Nitokra sp. was observed. Please note that chemical parameters were found to be within the limits established by CONAMA Resolution 454/2012. The sample from the Spring evidenced toxic effects in the tests with Nitokra sp. and S. costatum, which were not evidenced in the results of the chemical analyses, as compliance with the limits established by CONAMA Resolution 357/05 was confirmed for most of the chemical variables analyzed, as well as compliance with the standards established by CONAMA Resolution 454/2012.

Please note that the environmental matrix affected the ecotoxicological assessment of the marine environment, evidencing the differences in the bioavailability of pollutants present in the solid or dissolved fractions of the water column. Thus, in the matrices assessed, the surface water presented greater ecotoxicity, while samples of seabed water presented no toxic effects and the sediment evidenced an intermediate result.