title: Identification of the toxic constituents of sediments in a Brazilian subtropical estuary.
abstract: Phase 1 of the TIE method was applied to samples of elutriates from sediments of the Itajaí-Açu estuary and adjacent coastal region in southern Brazil. Embryo-larval toxicity assays were used with the sea urchin Arbacia lixula in samples of raw elutriate, and treated with Ulva fasciata, EDTA and sodium thiosulfate. Inside the estuary, ammonia was responsible for more than 40% of the toxicity in both the dredged and undredged regions. A toxicity gradient was observed, between the estuary and the coastal region, with an increase in the importance of metals for the latter. Temporally, there is strong evidence of the influence of dredging and disposal of sediments in the contamination of the coastal dumping site. The results indicating that this area presents limitations in its saturation capacity. Chemical analysis indicated the metal Cu is probably responsible for the toxicity of the sediments observed, without the interference of ammonia.
authors: Centro de Ciências Tecnológicas da Terra e do Mar (CTTMar), Universidade do Vale do Itajaí (UNIVALI), Cx.P. 458, Itajaí, SC 88302-202, Brazil.
authors: Fernanda
authors: F
authors: Poleza
authors: Centro de Ciências Tecnológicas da Terra e do Mar (CTTMar), Universidade do Vale do Itajaí (UNIVALI), Cx.P. 458, Itajaí, SC 88302-202, Brazil.
authors: Rafael C
authors: RC
authors: Souza
authors: Centro de Ciências Tecnológicas da Terra e do Mar (CTTMar), Universidade do Vale do Itajaí (UNIVALI), Cx.P. 458, Itajaí, SC 88302-202, Brazil. Electronic address: cresgalla@univali.br.
authors: Charrid
authors: C
authors: Resgalla
mesh_terms: D000641:Ammonia / Q000032:analysis / Q000633:toxicity; D001938:Brazil; D004784:Environmental Monitoring; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D008670:Metals / Q000032:analysis / Q000633:toxicity; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D000641:Ammonia
keywords: Dredging; Itajaí-Açu river; Sediment; TIE; Toxicity