Toxicity identification and evaluation of a refinery wastewater from Brazil (Phase I)

Petroleum refineries generate a large amount of effluents, which if released without appropriate treatment can cause chronic effects to organisms. Most studies show that many contaminants can be responsible for the toxicity, among them ammonia, sulfide, cyanide, phenol and hydrocarbons. The present study evaluated the cause of the chronic toxicity of a refinery wastewater from Brazil using the organism Ceriodaphnia dubia in short-term test. The results suggest that metals such as barium, manganese and strontium can be contributing for the toxicity of the wastewater. Besides this, conductivity could be contributing to the toxicity too, since the level is high for the test organism evaluated.Â

Estudo hidrográfico e planctonológico da região entre Cabo Frio (Rio de Janeiro) e o Arquipélago de Abrolhos (Bahia) - Brasil

Plankton and hydrographic data were made on 99 samples collected from July 26th to September 20th 1984 off the Brazilian coast between Cabo Frio (RJ) and Abrolhos Archipelago (BA)» during "Espírito Santo I" Oceanographic Expedition» with the objective of obtaining informations on winter hydrographic features and upwelling studies on the bank system Vitoria - Trindade. The Tropical Water was dominant in the upper 200 m, and the South Atlantic Central Water was present above 100 m between Cabo Frio and Guarapari. The nutrient values (nitrate 104 cel. I*1) e zooplâncton (2.000 ind.m'3) ocorreram nas estações próximas a costa. Entretanto, o fitoplâncton apresentou também altas densidades nas estações próximas aos bancos oceânicos. A análise de componentes principais foi usada para descrever variações na abundância do plâncton relacionada com as condições hidrográficas. Dois fatores foram interpretados, explicando 49,5% da variância, como soido a influência do gradiente nerítico-oceânico e a oposição entre água oligotróficas e eutróficas

Brazilian silverside, Atherinella brasiliensis (Quoy & Gaimard,1825) embryos as a test-species for marine fish ecotoxicological tests

The fish embryo test (FET) is an alternative to the classic freshwater toxicity test used to assess environmental hazards and risks to fish. This test has been standardized and adopted by the Organization for Economic and Cooperation and Development (OECD). As salinity may affect the substances’ toxicity, we describe the development of an alternative euryhaline test species for embryonic ecotoxicological tests: the Brazilian silverside Atherinella brasiliensis (Quoy & Gaimard, 1825). This species is broadly distributed along the coast of South America and is able to inhabit a broad range of environmental and saline conditions. Ours is the first study on the maintenance of a native South American species for natural reproduction and the generation of embryos for tests. The embryos used are transparent and possess fluorescent cells which have only been seen in a few species and which may be used as markers, making it an alternative assessment tool for the lethal and sublethal substances in marine and estuarine environments. We provide a detailed description and analysis of embryonic development under different salinities and temperatures. The embryos and larvae developed in similar ways at different salinities, however as temperatures increased, mortality also increased. We considered the effects of the reference toxicants Zn2+ and SDS using a protocol similar to the FET that was standardized for zebrafish. Brazilian silverside embryos are as sensitive as freshwater, or euryhaline fish, to the surfactant but are more resistant to metals prior to hatching. We were able to show the advantages of the Brazilian silverside as a model for a marine fish embryo test (FETm) with high levels of reproducibility and little contaminated waste