Bioaccumulation and biomagnification of heavy metals in trophic webs of estuaries of the southern and southeastern of Brazil

A região costeira do Brasil é historicamente impactada por atividades antrópicas, que liberam contaminantes, como os metais pesados. Nos estuários de Paranaguá (PR), Cananéia e Santos (SP), tais atividades estão presentes em diferentes níveis. Neste estudo foram investigadas as concentrações de arsênio, cádmio, chumbo, cobre, cromo, níquel, selênio, zinco e mercúrio, além de isótopos estáveis de carbono e nitrogênio, em sedimentos, fragmentos vegetais e organismos marinhos, como invertebrados bentônicos, peixes bentívoros e mamíferos marinhos, coletados nos três estuários. As amostragens foram realizadas em 2015, sendo as análises de isótopos realizadas por EA-IRMS e as análises de metais pesados realizadas por ICP OES-VGA e ICP-MS. As razões isotópicas permitiram a distinção entre fontes de matéria orgânica e nível trófico. Exemplares da ictiofauna e de cetáceos analisados não apresentaram distinção entre os níveis tróficos 3 e 4, indicando uma dieta generalista para estes animais e potencial compartilhamento de nicho trófico. Os metais apresentaram maiores concentrações nos sedimentos do estuário de Santos, coincidindo com o local com maior intensidade de atividades antrópicas. Comparando os estuários há maior acumulação de: Cr, Cu, Zn e Hg em Paranaguá, As e Pb em Cananéia, e Cd, Ni e Se em Santos, resultados justificados por atividades antrópicas, fontes naturais e características geoquímicas de cada região. A tendência de biomagnificação de Se foi observada nas teias tróficas de todos os estuários, e de Zn e Hg nas teias de Paranaguá e Cananéia. Entretanto, As, Cr, Cu, Ni e Pb demostraram tendência a biodiluição nas teias tróficas estudadas, com maior bioacumulação em invertebrados bentônicos. Portanto, este estudo traz um panorama atual da distribuição espacial e trófica de metais pesados nos estuários, colaborando com o monitoramento e ações de gestão costeira.The coastal region of Brazil is historically impacted by anthropic activities, which release contaminants such as heavy metals. In the estuaries of Paranaguá (PR), Cananéia and Santos (SP), these activities are present in different levels. In the present study, concentrations of arsenic, cadmium, lead, copper, chromium, nickel, selenium, zinc and mercury were investigated, as well as stable carbon and nitrogen isotopes in sediments, plant fragments and marine organisms such as benthic invertebrates, benthivorous fish and marine mammals, collected in the three estuaries. Samples were collected in 2015, with isotope analysis performed by EA-IRMS and heavy metal analysis performed by ICP OES-VGA and ICP-MS. Isotopic ratios allowed the distinction between organic matter sources and trophic level. The specimens of the ichthyofauna and cetaceans analyzed did not present distinction between trophic levels 3 and 4, indicating a generalist diet for these animals and a potential sharing of trophic niche. The metals have presented higher concentrations in the sediments from Santos estuary, what coincides with the place with greater intensity of anthropic activities. Comparing the estuaries, there is more bioaccumulation of Cr, Cu, Zn and Hg in Paranaguá, As and Pb in Cananéia, and Cd, Ni and Se in Santos; results which are justified by anthropic activities, natural sources and geochemical characteristics of each region. A biomagnification tendency of Se was observed in the trophic webs of all estuaries, and Zn and Hg in the Paranaguá\'s and Cananéia\'s webs. However, As, Cr, Cu, Ni and Pb displayed a tendency to biodilution in the studied trophic webs; with a higher bioaccumulation in benthic invertebrates. Therefore this study provides a current overview of the spatial and trophic distribution of heavy metals in the estuaries. Thus, it is collaborating with the monitoring and actions of coastal management

Bioaccumulation of heavy metals and assessment of biomagnification in biota of Almirantado Bay, Rei George Island, Antarctica

O continente Antártico é considerado um ambiente pouco impactado, porém com o aumento das atividades humanas e do número de estações de pesquisa, há uma tendência de aumento dos níveis de alguns contaminantes. Neste estudo estabeleceram-se os níveis de arsênio, cádmio, chumbo, cobre, cromo, mercúrio, níquel, zinco, e a razão isotópica de nitrogênio, em sedimentos e na biota, coletados em 2003, na Baía do Almirantado, Ilha Rei George, Antártica. Os metais pesados foram quantificados por Espectrometria de Emissão Ótica com Plasma Indutivamente Acoplado (ICP-OES). Os resultados demonstraram elevadas concentrações de cobre e zinco nos sedimentos, atribuídas à composição geológica da região. Verificou-se bioacumulação de arsênio na biota da Baía do Almirantado, e bioacumulação de cádmio e zinco na biota da Enseada Martel. Somente cobre apresentou tendência de biomagnificação na teia trófica estudada. O molusco Laternula elliptica se apresentou como um bom biomonitor das concentrações de metais pesados para o ambiente Antártico. Além disso, os resultados foram úteis para o conhecimento dos níveis de metais pesados nas condições pré-acidente da Estação Antártica Comandante Ferraz (EACF), que ocorreu em 2012, e para comparação com as atuais condições, dentro dos trabalhos de monitoramento que estão sendo realizados pelo INCT-APA (Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisas Ambientais).The Antarctic continent is considered a slightly affected environment, but as the human activities and the number of research stations are increasing, there is a tendency of a higher level of some contaminants. This study established the levels of arsenic, cadmium, lead, copper, chromium, mercury, nickel, zinc, and nitrogen isotope ratios in sediments and biota collected in 2003, in Almirantado Bay, Rei George Island, Antarctica. Heavy metals were quantified by Optical Emission Spectrometry with Inductively Coupled Plasma (ICP-OES). The results showed high concentrations of copper and zinc in sediments attributed to the geological composition of the region. There was arsenic bioaccumulation in biota of Almirantado Bay, and bioaccumulation of cadmium and zinc in the biota of Martel Bay. Only copper tended to biomagnification in the trophic web studied. The clam Laternula elliptica presented itself as a good biomonitor of heavy concentrations of metals for Antarctic environment. Moreover, the results were useful for the acknowledge of the levels of heavy metals in pre-accident conditions of Comandante Ferraz Antarctic Station (EACF), which occurred in 2012, and for comparison with current conditions within the monitoring work now performed by INCT-APA (National Antartic Institute of Science and Technology Environmental Research)

Elementos-traço em Cathorops spixii (Pisces, Ariidae) no complexo estuarino de Paranaguá

Resumo: No Complexo Estuarino de Paranaguá (CEP), Paraná, atividades urbanas, portuárias, industriais, agrícolas e pesqueiras impactam o sistema e sua biota pela liberação de contaminantes, como os elementos-traço. A avaliação destes contaminantes e sua influência sobre organismos aquáticos constitui uma preocupação atual, em razão de suas características como persistência, bioacumulação e toxicidade. Este trabalho investigou as variações espaciais de cádmio (Cd), zinco (Zn), cromo (Cr), cobre (Cu), chumbo (Pb), níquel (Ni) e arsênio (As) no tecido muscular dorsal, da espécie de peixe demersal e estuarina residente Cathorops spixii no CEP. Pretendeu-se ainda estabelecer relações entre as concentrações de elementos-traço e fatores biológicos sexo, comprimento e peso e verificar se o C. spixii funciona como bioindicador da contaminação por elementos-traço no sistema em questão. As campanhas de amostragem foram realizadas em março de 2011, nos setores Baía de Paranaguá e Baía de Antonina do eixo leste-oeste (perfil poluído), e setores Guaraqueçaba e Enseada do Benito do eixo norte-sul (perfil controle). As amostras compreenderam 48 exemplares de C. spixii, dos quais foram retiradas amostras do tecido muscular dorsal, seguindo a metodologia descrita em LANA et.al. (2006), as quais foram analisadas por ICP-OES. Nossos resultados apontaram padrões de distribuição espacial para todos os elementos, porém não diferiram quanto ao sexo dos exemplares de C. spixii. Foram verificadas correlações positivas com o tamanho e o peso para as concentrações de Cu e Ni, e negativas para As, Cr e Zn. A espécie se mostrou um bom bioindicador das concentrações de traços no CEP. Cobre e níquel não violaram os limites da legislação para consumo humano, porém cromo e zinco apresentaram níveis acima do limite máximo permitido pela legislação. A concentração de arsênio em C. Spixii, ultrapassou estes limites bem como os teores encontrados em peixes de diferentes sistemas nacionais e internacionais, indicando uma grave contaminação do CEP por este metal. Palavras chave: Elementos-traço. Cathorops spixii. Complexo Estuarino de Paranaguá

Mercury in Brown Booby (Sula leucogaster) Feathers from the São Pedro and São Paulo Archipelago as a Tool for Environmental Biomonitoring

Seabirds are important bioindicators of environmental quality as their feathers contain records of metal concentration. Among the metals, mercury (Hg) is toxic, causing damage to the organism even in small concentrations. The objective of this study is to determine and evaluate the total Hg levels in brown booby feathers in the São Pedro and São Paulo archipelago (SPSPA) (0º55´02´´N; 29º20´42´´W), comparing to literature levels of metal in feathers of different Sula species in several locations from Brazil and elsewhere in the world. To determine Hg levels, the study uses the methodology of partial digestion of collected feathers, followed by the analysis by inductively coupled plasma optical emission spectrometry (ICP-OES). The average value of the Hg concentration was 2.6 ± 3.5 mg L-1, which is below the threshold for the occurrence of adverse effects due to mercury toxicity in seabirds. For the statistical analysis of comparison between sexes of the SPSPA population, and for comparison between species of the genus Sula in different places around the world, this study uses Analysis of Variance (ANOVA), followed by the Tukey test. There was no significant difference between sexes in Hg concentration. However, there was a significant difference between the compared sites, demonstrating that the SPSPA has a low Hg concentration, differing only from Daphne Island, Galapagos a region with high Hg atmospheric deposition due to its climatic conditions. Between the species of the genus Sula, the study detected a significant difference in the accumulation of Hg. The species S. leucogaster differed from the species S. granti, which is also associated with Galapagos. The other species displayed accumulation of Hg resembling that of S. leucogaster, confirming a similarity between their nourishment habits and their trophic niches. The results support future Hg monitoring programs in this important Marine Conservation Unit and Environmental Protection Area.&nbsp

Trophic dynamics in two South American estuaries encompassing industrial development and a biodiversity hotspot

Estuaries are critical to the life histories and development of many marine species, and support some of the most productive aquatic ecosystems. However, owing to their geographic accessibility, many estuaries face considerable anthropogenic threats, which can be exacerbated in developing nations. Understanding the ecological implications of anthropogenic activities as a precursor to dedicated conservation activities requires comprehensive assessments of baseline trophic relationships. This study addresses a shortfall in such information for two tropical, coastal ecosystems globally identified as priority areas for biodiversity conservation: the Paranagua estuarine complex; and the Cananeia-Iguape estuarine lagoon system in southern Brazil. Ecological relationships were investigated through carbon and nitrogen stable isotope (delta C-13 and delta N-15) determination in sediments, plant fragments and the muscle tissues of marine species occupying different trophic levels, including benthic invertebrates, ichthyofauna (Stellifer rastrifer, Paralonchurus brasiliensis, and Isopisthus parvipinnis), and delphinids (Sotalia guianensis and Pontoporia blainvillei). Isotope ratios facilitated distinguishing plant fragments, sediments (which were terrestrially influenced) and biota (predominantly marine influenced). However, despite variation among anthropogenic stressors, isotope ratios did not vary between the studied estuaries, implying similar impacts on trophic relationships which might reflect some inter-estuary mixing. All ichthyofauna and the delphinids had similar generalist diets and shared the same trophic niche, which may reflect their consistent spatio-temporal distributions and habitat patterns in the estuaries. The data illustrate the utility of isotopically characterizing biodiversity-hotspot estuaries as a mechanism for rapidly assessing ecological relationships between key species and regional habitats. Such an approach can be used to evaluate ecological connectivity as a baseline for management and might be applied more broadly, embracing multiple regions as part of estuarine and coastal biome conservation efforts

Chemical characterization of deep-sea corals from the continental slope of Santos Basin (southeastern Brazilian upper margin)

Carbonate mounds and pockmarks are geologically and ecologically important features distributed worldwide in the world’s oceans. In the present study, we present a chemical characterization of deep-sea scleractinian coral skeletons collected in these geomorphological areas at the southeastern continental margin of Brazil. Coral samples were collected from ten sampling stations during cruises aboard the R/V Alpha Crucis, in 2019. Three species of scleractinian corals were studied: Enallopsammia rostrata, Solenosmilia variabilis, and Desmophyllum pertusum. Stable isotopes of carbon and oxygen (δ13C and δ18O), metals, and phosphorus present in the coral carbonate skeletons were analyzed. Corals are recognized as archives of physical-chemical variations in the marine environment, and the Element/Ca ratios, δ13C, and δ18O allowed for the characterization of the studied areas. Chemical composition found in pockmark areas indicated affinity to terrigenous and particulate materials input (Ba/Ca, Fe/Ca, Mn/Ca, Li/Ca, and Mg/Ca). Greater availability of nutrients and anthropogenic materials (Pb/Ca, Cd/Ca, Zn/Ca, and P/Ca) is also likely to occur in this region, with some elemental ratios higher than those measured in other oceans. These mounds can act as barriers for metals from land flows. Also, corals benefit from a higher food supply due to stronger currents. The corals at the top of the Alpha Crucis Carbonate Ridge receive significant marine influence. Most coral samples have carbonate of aragonitic origin, except for a specimen of D. pertusum, which presented carbonate of biogenic calcite and aragonite. The results demonstrate the potential of scleractinian corals in the chemical characterization of the deep ocean and the need for further investigation of carbonate mound areas from the SW Atlantic

Globalization of the Antarctic seas: Pollution and Climate Change Perspectives

The Antarctic continent is entirely surrounded by the Antarctic Ocean alsonamed Southern Ocean, forming a barrier to the movement of organismsinto and out of Antarctica. Therefore, the Antarctic Continent has uniquecharacteristics because of its geographic isolation.It is regarded as one of the remaining environments on the planetwhere human activities have little direct impact. Thus, this region hasbeen considered an ideal observatory for research on global change andenvironmental impacts caused by man (Xuebin et al. 2006).Fil: Montone, Rosalinda. Instituto Oceanografico (iousp); Brasil. Universidade de Sao Paulo; BrasilFil: de Castro Martins, Cesar. Centro de Estudos do Mar, UFPR; BrasilFil: Maruch Tonelli, Marcos Henrique. Universidade de Sao Paulo; Brasil. Instituto Oceanografico (iousp); BrasilFil: Hoppe Trevizani, Tailisi. Universidade de Sao Paulo; Brasil. Instituto Oceanografico (iousp); BrasilFil: Caruso Bicego, Marcia. Universidade de Sao Paulo; Brasil. Instituto Oceanografico (iousp); BrasilFil: Lopes Figueira, Rubens Cesar. Universidade de Sao Paulo; Brasil. Instituto Oceanografico (iousp); BrasilFil: Coaracy Wainer, Ilana Elazari Klein. Universidade de Sao Paulo; Brasil. Instituto Oceanografico (iousp); BrasilFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge

Although carbonate mounds have been investigated for 100 years, few studies focus on the giant variety. The Alpha Crucis Carbonate Ridge (ACCR), a ~17 x 12-km ring-shaped ridge formed by hundreds of mounded structures, located between the 300 and 800-m isobaths and reaching a maximum height of 340 meters above the adjacent seafloor, is the first giant carbonate mounded feature described for the SW Atlantic margin. This study provides the first multiproxy approach to investigate sediments covering the ACCR and its adjacencies. Most of the area is located under the Intermediate Western Boundary Current (IWBC) flow, which carries the nutrient-rich Antarctic Intermediate Water (AAIW). Radiocarbon aging shows pronounced differences for the shallow layers (MIS3 for the top of the mounds and late Holocene for the adjacencies). Grain size data indicate the prevalence of sandy fractions on top of the mounds and muddy sediments in the adjacent areas. Fe/Ca and Ti/Ca proxies allowed for identifying mainly biogenic sedimentation in the area. However, the input of allochthonous terrigenous sediment is necessary for mound buildup, and values of Fe and Ti collected on the top of the mounds are significant. End-Members distributions and metal concentrations also allowed for recognition of distinct sources of sediment. εNd and Ln(Fe/K) indicated two primary terrigenous sources, the Precambrian rocks of the Brazilian shield (Cabo Frio end-member) and the multiple lithologies drained by the Rio de la Plata basin. Redox condition proxies indicated that the area is submitted to oxic conditions, probably reflecting the action of the IWBC. This work provides the first insight into an integrated grain-size and geochemical characterization of the Alpha Crucis Carbonate Ridge (southwestern Atlantic margin)

Methane-related community of a carbonate-enriched pockmark, Brazilian Southeastern continental slope

Pockmarks are geological features that often sustain hydrocarbon-related communities of microorganisms when active, seeping oil or methane. Microbial communities of inactive pockmarks have not been well studied until the present. Plenty of pockmarks in the Southwestern Atlantic Ocean have been discovered. However, no information is available about the organic characteristics in association with the microbial diversity related to methane and non-methane hydrocarbon consumption. This study examined the identity and potential ecology of the methane-related microbial community in an inactive SW Atlantic Carbonate-enriched Pockmark (SWACP). Undisturbed sediment cores were enriched with CH4 99.5% at 5°C, with samples harvested at 16h, 120h, 240h, 720h, and 960h, followed by metataxonomics functional prediction, and the correlation of microbial groups with incubation and enrichment types. The SWACP is depleted in organic compounds, and chemosynthetic production is dominant. Incubated mini-cores of sediment were affected by incubation time and enrichment type, which influenced the microbial composition. Although several taxa were shared among all sediment samples, specific groups per enrichment type and incubation time were observed. These communities comprised taxa previously reported in marine bottom waters, carbonate crusts, active cold-seeps, and inactive pockmarks. The methane-enriched taxa were predominantly related to aerobic methanotrophy, methylotrophy, aerobic and anaerobic non-methane hydrocarbon degradation, and fermentation. This study brings the first survey of the key microbial groups in methane fluxes of a Brazilian deep-sea pockmark, providing data for understanding the ecology surrounding the SW Atlantic gas field areas