Contamination and toxicity in a subtropical Estuarine Protected Area influenced by former mining activities

The present paper reviews information about sources, fate, concentrations and toxicity of the metals found in the Cananéia-Iguape Estuarine Complex (CIEC), which is within a Ramsar site, the Cananéia-Iguape-Peruíbe Environmental Protected Area (CIP-PA). The main sources of metals to CIEC are the former mining sites located upstream, on the Ribeira de Iguape River basin. Pb is reported as the element of primary concern, but Cu, Zn, Cr and As have been detected in sediments and biota. In general, higher levels of metals are associated with muddy sediments, in depositional portions of the estuary. Metals appear to be bioavailable, as sediment toxicity has been reported, together with bioaccumulation and sub-chronic effects in fish and invertebrates. Areas with higher concentrations of metals and more severe sediment toxicity are not necessarily the closest to the sources. The worse conditions occur in depositional sites, which depend on rainfall in catchment basin and hydrological processes in the estuary. In fact, during the flooding season the deposition of particles seems to move southward, carrying metals to the southern portion of the CIEC. The results suggest that the protection objectives are not being fully achieved, demanding actions to ensure control of both internal and external sources of contaminants for the CIEC. Additionally, new enforcements and actions are required to control the contamination sources of mining residues located upstream. The current review highlights that estuarine and marine protected areas may be impacted by contaminants released from distant sources, and this situation should be properly addressed in management plans

Sediment quality assessment of the tributaries of the Santos-São Vicente Estuarine System – Brazil

The Santos-São Vicente Estuarine System has a long history of environmental impacts, and several studies have been performed in this region. However, the quality of its tributaries was not previously studied. This study aimed to investigate the quality of sediments from five rivers (Santana, Mariana, Piaçabuçu, Quilombo, and Diana Rivers) and three sampling sites at Piaçaguera Canal (riverbed, right and left banks), by using an integrated approach involving chemical analyses and whole sediment toxicity tests. Chronic and acute toxicity tests were performed using, respectively, copepods Nitocra sp. and amphipods Tiburonella viscana. The studied sediments presented moderate to high levels of PAHs, PCBs, metals (Cu, Hg, Ni, Pb, Zn), and As. The majority of sediments produced chronic toxic effects, and samples from Piaçaguera Canal were consistently toxic in all acute and chronic tests. The integration of data through multivariate analyses indicated that the toxicity was closely related to the sediments contamination. Chemical data were compared with sediment quality guidelines, which evidenced that the site-specific values are adequate to predict impacts. The levels of organic chemicals and metals suggest constant inputs from diffuse and point sources, demanding actions to ensure effective control and management of the contamination sources to the estuary

Water and sediment toxicity in a river affected by former mining residues

A bacia do Rio Ribeira de Iguape foi palco de intensa atividade de mineração de chumbo e, como resultado, estima-se que o \ud rio Ribeira de Iguape tenha recebido a descarga de aproximadamente 5,5 t/mês de materiais ricos em As, Ba, Cd, Pb, Cu, Cr e \ud Zn. No presente trabalho, foi analisada a toxicidade de sedimentos e águas coletados ao longo do rio com o intuito de avaliar \ud a qualidade ambiental, tendo sido realizadas 3 campanhas de coleta, entre 2009 e 2010. Os testes de toxicidade aguda foram \ud conduzidos com o cladócero Daphnia similis, utilizando as amostras brutas de água e a exposição aos sedimentos pela interface \ud sedimento-água. Os resultados indicaram, em geral, ausência de toxicidade, tanto para sedimentos quanto para águas, com \ud efeitos tóxicos agudos registrados apenas episodicamente (toxicidade marginal). Tais resultados são coerentes com as baixas \ud concentrações de metais em águas e sedimentos indicadas na literatura, porém diferem do monitoramento feito pela agência \ud ambiental estadual, que tem registrado toxicidade crônica. Essa toxicidade aguda eventual indica, ainda, que embora a qualidade do Rio Ribeira de Iguape esteja sendo recuperada, as condições ainda não estão totalmente controladas.The Ribeira de Iguape River basin received intense mining activities for lead exploiting and, as a result, the river received the \ud discharges of estimated amounts of 5.5 tons/month of material rich in As, Ba, Cd, Pb, Cu, Cr and Zn. In this article, the toxic-ity of waters and sediments collected in Ribeira de Iguape River was assessed aiming to estimate environmental quality. Three \ud sampling campaigns were conducted, from 2009 to 2010. Toxicity tests with the cladoceran Daphnia similiswere done for water \ud samples and for sediments, in this case using sediment-water interface exposure. Results showed in general absence of toxicity \ud for sediments and waters, and only eventually were acute effects registered (marginal toxicity). Results are consistent with the \ud conditions indicated by the literature, of low concentrations of metals in waters and sediments; however they differ from the \ud monitoring made by the state environmental agency, which registered chronic toxicity. The occurrence of eventual acute toxicity \ud indicates that although Ribeira de Iguape River quality is being restored, conditions still are not totally under control.FAPESPFundação de Amparo a Pesquisa do Esta-do de São Paulo (FAPESP) - Processos n. 2008/54607-5 e n. 2009/52762-

Ecological Risk Assessment due to metal contamination in the South of the Estuarine Complex of Cananeia-Iguape

O histórico de contaminação por metais no Vale do Rio Ribeira de Iguape é bem conhecido, com evidências de transporte destes contaminantes ao Complexo Estuarino Lagunar de Cananéia-Iguape (CELCI), adsorvidos ao material em suspensão. Assim, os metais podem alcançar o setor sul do CELCI, podendo acumular nos sedimentos e nos organismos filtradores. Neste estudo foi realizada uma avaliação de risco ecológico no CELCI associado à presença de metais oriundos das antigas áreas de mineração do Alto Ribeira, utilizando diferentes linhas de evidência. Os resultados foram avaliados de forma integrada, incluindo análises geoquímicas e biológicas (ensaios de toxicidade aguda, medidas de bioacumulação e biomarcadores bioquímicos em brânquias de bivalves). Os sedimentos apresentaram níveis moderados a altos de metais e toxicidade aguda, a qual foi associada, especialmente, com as concentrações de Cu, Pb e Zn. Da mesma forma estes metais foram encontrados em concentrações altas nos tecidos de bivalves. Os biomarcadores bioquímicos (MT, GSH, GST, GPx, GR, AChE, LPO e danos em DNA) indicaram a ocorrência de efeitos significativos nos bivalves. Portanto, os resultados mostram que os metais estão sendo carreados para a porção sul do estuário, causando bioacumulação e efeitos nos organismos aquáticos e, portanto, gerando riscos ecológicos para o CELCI.The historic of contamination by metals in the Valley of Ribeira de Iguape River is well known, and there are evidences that these chemicals are carried to the Estuarine Complex of Cananeia-Iguape (ECCI), adsorbed on the suspended particles. Metals can thus reach the south of the ECCI, where they may accumulate in the sediments and filter feeding organisms. This study aimed to evaluate the ecological risks associated to the metals originated from the former mining areas of the upstream Ribeira de Iguape River, by using different lines of evidence, which included geochemical and biological analysis (acute toxicity tests, bioaccumulation and biochemical biomarkers in bivalves\' gills). The sediments presented moderate to high levels of metals and acute toxicity, which was correlated with the concentrations of metals (Cu, Pb and Zn). These elements were found in high concentrations in the bivalves soft tissues. The biochemical biomarkers (MT, GSH, GST, GPx, GR, AChE, LPO, and DNA damage) indicated the occurrence of significant effects in the bivalves. Therefore, the results showed that metals are carried into the South portion of the estuary, accumulating in the biota and causing negative effects to the aquatic organisms, producing thus ecological risks to the ECCI

Organotin contamination in South American coastal areas

Organotin compounds(OTs)were used in antifouling paints for more than four decades. However, due to their wide spread intensive use and high toxicity, undesirable effects in non-target marine organisms have been detected since the early 1980s. Consequently, the International Maritime Organization banned new maritime applications of these products on January 1, 2003 and their presence on ship hulls from January 1, 2008. Although extensively studied in Europe, North America, Oceania, and Asia, environmental levels and effects of organotin contamination are still poorly known for South America. Thus, the current review aimed to present the actual status of this problem in South America by summarizing and comparing the available data in the literature. An over view of the OTs concentrations in sediment and biota and their effects, mainly imposex in marine gastropods, are presented. This work showed that in Atlantic coastal areas of South America there are “hotspots” of OTs contamination, similar to that observed in industrialized countries of Northern Hemisphere. On the other hand, the number of accomplished studies in the Pacific coast is extremely low. Despite the limitation on studies about OTs environmental levels and their relate deffects, the available data pointed out for a wide spread TBT contamination along the South American coastal areas. Therefore, the establishment of base lines of organotin contamination in the Pacific coast and the implementation of temporal trend studies in the South American coastal areas is crucial to verify the effectiveness of local regulations and OTs global ban, and to map the most sensitive areas related to present and future antifouling impacts

Comparative toxicity of antifouling compounds on the development of sea urchin

In the present study, embryotoxicity experiments using the sea urchin Lytechinus variegatus were carried out to better clarify the ecotoxicological effects of tributyltin (TBT) and triphenyltin (TPT) (the recently banned antifouling agents), and Irgarol and Diuron (two of the new commonly used booster biocides). Organisms were individually examined to evaluate the intensity and type of effects on embryo-larval development, this procedure has not been commonly used, however it showed to be a potentially suitable approach for toxicity assessment. NOEC and LOEC were similar for compounds of same chemical class, and IC10 values were very close and showe overlapping of confidence intervals between TBT and TPT, and between Diuron and Irgarol. In addition, IC10 were similar to NOEC values. Regardless of this, the observed effects were different. Embryo development was interrupted at the gastrula and blastula stages at 1.25 and 2.5 μg l−1 of TBT, respectively, whereas pluteus stage was reached with the correspondin concentrations of TPT. Furthermore, embryos reached the prism and morula stages at 5 μg l−1 of TPT and TBT, respectively. The effects induced by Irgarol were also more pronounced than those caused by Diuron. Pluteus stage was always reached at any tested Diuron concentration, while embryogenesis was interrupted at blastula/gastrula stages at the highest concentrations of Irgarol. Therefore, this study proposes a complementary approach for interpreting embryo-larval responses that may be employed together with the traditional way ofanalysis. Consequently, this application leads to a more powerful ecotoxicological assessment tool focused on embryotoxicity

Developing a protocol whole sediment toxicity testing with the polychaete Armandia agilis

Sediments constitute a key compartment of coastal and marine ecosystems. They also constitute the ultimate sink for most of the chemical substances and a source of contamination to the benthic fauna. In this study, we aimed to develop a protocol for acute toxicity tests using the polychaete Armandia agilis as a model species. To achieve that, we evaluated the species tolerance to the salinity of overlying water (in the presence and absence of sediment), the tolerance to sediments with different particle sizes, the sensitivity to reference substances (potassium dichromate – K2Cr2O7, zinc sulfate – ZnSO4; and Sodium Dodecyl Sulfate - SDS), and the responses to clean and contaminated sediments. The species survives in several latitudes on the American coast (North Carolina, Gulf of Mexico, and South-Southeast of Brazil) in different haline conditions (above 20) in typically sandy textures. In Ilhabela (SE Brazil), the species was available throughout the year. The LC50-48h values calculated to the K2Cr2O7, ZnSO4, and SDS, were 20.94 (33.38-14.04); 4.25 (7.66-2.98); 4.90 (6.59-3.84) mg L-1 respectively; thus A. agilis can be considered as sensitive as other benthic organisms. The responses of A. agilis to environmental sediments were similar to those exhibited by the amphipod Tiburonella viscana, showing that this polychaete is responsive to contaminated sediments. Armandia agilis can be considered a promising organism to be used in sediment toxicity tests

Levels of hydrocarbons and toxicity of water-soluble fractions of maritime fuels on neotropical invertebrates

Accidents involving fuels and oil spills are among the main sources of hydrocarbons to the marine ecosystems and often damage the biota. Diesel and bunker oil are two examples of fuels with broad application that release hydrocarbons to the aquatic environment and little is known about their toxicity on tropical organisms. This study aimed to assess the toxicity of the water-soluble fraction (WSF) of diesel and bunker oils to neotropical marine invertebrates. Commercial fuels were purchased for WSF extraction, analyzed for total petroleum hydrocarbons (TPH), and polycyclic aromatic hydrocarbons (PAHs), and acute and chronic toxicity determined. The WSF analyzed contained varied levels of TPH and PAHs mixtures, especially low molecular weight PAHs; bunker WSF presented higher amounts of TPH and PAHs. Both WSFs tested produced significant mortality of the brine shrimp Artemia salina, affected the reproduction rate of the copepod Nitokra sp, and impaired the embryo-larval development of the mussel Perna perna and of the sea urchin Lytechinus variegatus. In general WSF from diesel was more toxic to the organisms tested, but bunker WSF was more toxic to embryos of L. variegatus. Toxicity started from concentrations of 3% WSF, which can be environmentally relevant after an oil spill, indicating that marine biota may be adversely affected in short term.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP: 2020/00068-8FAPESP: 2013/15482-0CAPES: 88887.124100/2016-00CNPq: 311609/2014-7CNPq: 308533/2018-

Toxicidade de águas e sedimentos em um rio afetado por atividades mineradoras pretéritas

The Ribeira de Iguape River basin received intense mining activities for lead exploiting and, as a result, the river received the discharges of estimated amounts of 5.5 tons/month of material rich in As, Ba, Cd, Pb, Cu, Cr and Zn. In this article, the toxicity of waters and sediments collected in Ribeira de Iguape River was assessed aiming to estimate environmental quality. Three sampling campaigns were conducted, from 2009 to 2010. Toxicity tests with the cladoceran Daphnia similis were done for water samples and for sediments, in this case using sediment-water interface exposure. Results showed in general absence of toxicity for sediments and waters, and only eventually were acute effects registered (marginal toxicity). Results are consistent with the conditions indicated by the literature, of low concentrations of metals in waters and sediments; however they differ from the monitoring made by the state environmental agency, which registered chronic toxicity. The occurrence of eventual acute toxicity indicates that although Ribeira de Iguape River quality is being restored, conditions still are not totally under control