Abstract Understand the origin, transport, and character of organic matter entering Antarctic fjords is essential as they are major components of the global carbon cycle and budget. Macromolecular pools of particulate organic matter, bulk organic geochemistry, major and trace elements in surface sediments from Collins Bay were analysed as source indicators. Oceanographic conditions, bathymetry (multibeam) and grain size were considered as environmental controlling factors. Sediment samples were taken with a van Veen grab, during the ANTAR XXV Peruvian expedition (February 2018), onboard the R/V “BAP Carrasco” from the Peruvian Navy. Biopolymeric composition revealed the predominance of fresh marine protein-rich organic matter in the seafloor of Collins Bay, denoting high quality food resource for marine benthic heterotrophs. Based on Igeo values (between 0 and 1) Collins Bay can be considered unpolluted with natural levels of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Distribution of most of these elements with a gradient of decrease from the shallow inner fjord towards the outer deepest fjord, suggest their association with the deposition of detrital material and lithogenic particles supplied by Collins Glacier frontal ablation and runoff. This first comprehensive baseline information would assist in interpreting downcore sedimentary reconstructions and future climate-induce changes.

Resumo Estuários são ecossistemas costeiros que sustentam uma ampla variedade de serviços ambientais para a humanidade. Estuários abrigam muitos ambientes bentônicos com características específicas e seriamente ameaçados globalmente. Manguezais, marismas e planícies de maré são amplamente impactados por poluentes domésticos e industriais, por atividades comerciais que levam à perda de habitat e pela sobrepesca. Os diversos impactos locais, associados a mudanças regionais e globais na hidromorfologia estuarina e potenciais efeitos de mudanças climáticas, colocam sérias ameaças a ecossistemas estuarinos. A rede Bentos foi criada para estudar o efeito de mudanças no clima em ecossistemas bentônicos costeiros brasileiros. Este trabalho faz parte dos esforços iniciais do Grupo de Trabalho Estuários em rever o conhecimento sobre comunidades bentônicas estuarinas no Brasil. Aqui apresentamos uma breve revisão crítica sobre os trabalhos realizados objetivando o estudo, em nível de comunidades, do bentos estuarino e processos ecológicos associados. A partir do cenário atual, realizamos recomendações de estudo para responder questões científicas sobre efeitos de mudanças climáticas em comunidades bentônicas estuarinas, e enfatizamos a necessidade de bases de dados contínuas e de longa duração e o estabelecimento de parcerias internacionais com foco específico nos estuários brasileiros.

Abstract Estuaries are unique coastal ecosystems that sustain and provide essential ecological services for mankind. Estuarine ecosystems include a variety of habitats with their own sediment-fauna dynamics, all of them globally undergoing alteration or threatened by human activities. Mangrove forests, saltmarshes, tidal flats and other confined estuarine systems are under increasing stress due to human activities leading to habitat and species loss. Combined changes in estuarine hydromorphology and in climate pose severe threats to estuarine ecosystems on a global scale. The ReBentos network is the first integrated attempt in Brazil to monitor estuarine changes in the long term to detect and assess the effects of global warming. This paper is an initial effort of ReBentos to review current knowledge on benthic estuarine ecology in Brazil. We herein present and synthesize all published work on Brazilian estuaries that has focused on the description of benthic communities and related ecological processes. We then use current data on Brazilian estuaries and present recommendations for future studies to address climate change effects, suggesting trends for possible future research and stressing the need for long-term datasets and international partnerships.

Resumo O presente trabalho objetiva testar a viabilidade do emprego de alguns indices bióticos para o Mar Caspio Sudeste. Para tanto, a qualidade ecológica da lagoa Gomishan foi utilizada para avaliar três indices bióticos (AMBI, BENTIX, BOPA) durante o verão e o outono de 2010. Os resultados da aplicação dos indices não permitiram uma distinção clara entre as estações de coleta. Dois dos indices (AMBI e BENTIX) são bastante próximos em termos de diagnose (bom ou alto) e parecem funcionar melhor do que o BOPA. Adicionalmente, a Análise em Componentes Principais (ACP), baseada em parâmetros abióticos, mostrou claras diferenças espaciais e temporais nas variáveis ambientais. Contudo, nesses locais rasos e sem pressão do homem e com alto tempo de residência da água, a composição da comunidade bêntica pode ser associada ao estressse físico, devido ao aumento de salinidade e mudanças nas características ambientais, aliado a mudanças sazonais convencionais. A variabilidade natural de águas de transição mostrou ser um fator crucial para a correta avaliação da condição ecológica das comunidades de macroinvertebrados ao longo do sistema lagunar.

Abstract This paper aims to test the suitability of some biotic indices for their application in Southeast Caspian Sea. For this purpose, the ecological quality of the Gomishan lagoon was assessed using three biotic indices (AMBI, BENTIX, BOPA) during summer and autumn 2010. The results from the application of the biotic indices do not highlight a clear distinction between the stations. The results show that two of the indices (AMBI and BENTIX) are very close in terms of diagnosis (good and high) and seem to generally perform better than BOPA. In addition, Principal Component Analysis (PCA) based on abiotic parameters showed clear spatial and temporal differences in environmental variables. However, at this shallow sites with low human pressure and high water residence times, such benthic community composition can be associated with physical stress due to salinity increase and to changes in environmental characteristics, triggered by conventional seasonal variations. Natural variability of transitional waters is a crucial factor for a correct evaluation of the ecological condition of macroinvertebrate communities across the lagoonal system.

ResumoA cidade de Montevidéu, com mais de 1,5 milhões de habitantes, circunda a Baía de Montevidéu, onde um dos portos mais ativos e poluídos da América do Sul está localizado. No presente trabalho, foram avaliados esteróis fecais, metais traço, compostos organoclorados e derivados de petróleo nos sedimentos superficiais do Porto de Montevidéu, analisando sua distribuição espacial no interior do porto, bem como em dois dos principais tributários que chegam ao interior da baía. Especificamente para os sítios do porto, foi realizada uma comparação temporal dos metais pesados e hidrocarbonetos, considerando dados pretéritos de 12 anos. Foram observadas alterações significativas nos sítios estudados. Metais, tais como o Pb, Cr e Zn, apresentaram redução nas suas concentrações, enquanto os hidrocarbonetos alifáticos aumentaram seus valores em quase todas as estações. Foram observadas também diferenças entre o verão e o inverno, sugerindo mudanças no padrão de sedimentação, nos ingressos de substâncias e/ou mudanças hidrodinâmicas na área. Os resultados podem vir auxiliar na compreensão do estado atual e para o desenvolvimento de medidas de gestão necessárias para melhorar a qualidade ambiental do porto e da baía.

AbstractSituated opposite the Freshwater Front, Montevideo city with its more than 1.5 million inhabitants encircles Montevideo Bay, where one of the most active and polluted harbors in South America is located. Faecal sterols, trace metals, organochlorine compounds and petroleum derivatives in the sediments of Montevideo Harbor were evaluated and their spatial distribution inside the harbor as well as in the input of two main tributary streams analyzed. Specifically for the harbor sites, a temporal comparison of metal and hydrocarbons was made with previous measurements taken 12 years ago. Clear changes were observed at these sites. The concentration of metals such as Pb, Cr and Zn have diminished, while aliphatic hydrocarbons have increased their values at almost all of the stations studied. Differences were observed between summer and winter suggesting sedimentation, input or hydrodynamic changes in the area. These results help one to understand the present situation and develop the management measures needed to improve the environmental quality of the harbor and bay.

ResumoO conhecimento dos danos no DNA em organismos aquáticos de áreas poluídas é uma questão importante, já que a contaminação pode vir a alterar os organismos em níveis subletais. Apesar dos moluscos terem sido amplamente utilizados para monitorar a poluição da água, não há registros de estudos in vivo de genotoxicidade. Heleobia cf. australis é um pequeno gastrópode amplamente distribuído em quase todos os ecossistemas costeiros uruguaios, inclusive em locais altamente poluídos. O ensaio do cometa é um biomarcador genético do dano baseado na migração de fragmentos de DNA com carga negativa produzidas por agentes mutagênicos. Foram coletados indivíduos vivos na Baía de Montevidéu (área impactada) e Laguna Garzón (área controle) para analisar a presença de agentes mutagênicos que ocasionassem dano genético. Células de organismos da área impactada apresentaram níveis significativamente mais elevados de danos genéticos do que os obtidos na área controle. Esse nível de dano foi medido pela porcentagem de DNA na cauda. Embora preliminar, esta abordagem apoia a noção de que H. cf. australispoderia ser usado como sentinela para avaliar a presença de agentes mutagênicos em ambientes estuarinos, alertando sobre o impacto da poluição em estágios iniciais.

AbstractThe knowledge of the extent of DNA damage in aquatic organisms in polluted areas is an important issue because contamination may alter their health at sublethal levels. Although molluscs have been widely used to monitor water pollution, there are no records of in vivo genotoxicity studies. Heleobia cf. australis, is distributed in almost all Uruguayan coastal ecosystems, including highly polluted sites. The comet assay is a damage genetic biomarker based on the migration of negatively charged DNA fragments produced by mutagenic agents in individual cells. Live individuals were collected in the Montevideo Bay (impacted area) and Laguna Garzón (control) to analyze the presence of mutagenic agents in the former site through comet assay. Cells from organisms of the impacted area showed significantly higher levels of genetic damage than those obtained in the control population, measured by percentage of DNA in the tail. Although preliminary, this approach supports the idea that H. cf. australis could be used as a sentinel to evaluate the presence of mutagenic agents in estuarine environments, alerting to the impact of contamination in its early stages.

The Río de la Plata Estuary (RdlP) is a fluviomarine system that drains into the Southwestern Atlantic Ocean with the Paraná and Uruguay rivers as main tributaries. The estuary is fed by a 3,100,000 km2 catchment area which extends over the territories of Argentina, Paraguay, Brazil, Bolivia and Uruguay (Acha et al., 2008). The RdlP exhibits significant natural decadal- and annual-scale, hydrodynamic and oceanographic variability associated with the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO) and the El Niño/ La Niña Southern Oscillation (ENSO) (Depetris and Pasquini, 2007b; Chiessi et al., 2009; Garreaud et al., 2009). Such variability affects the moisture budget over the surrounding continental areas and leads, thus, to changes in the river discharge. PDO is associated with ENSO as both appear to display similar hydrological responses, though their inherent mechanisms are not yet fully understood (Garreaud et al., 2009). In this sense, warm and cold PDO phases strongly resemble El Niño and La Niña events, respectively (Garreaud et al., 2009). During El Niño episodes, an increase in precipitation over the RdlP drainage basin is commonly observed (Boulanger et al., 2005; Camilloni, 2005; Garreaud et al., 2009; García-Rodríguez et al., 2014), and consequently increased Paraná and Uruguay river discharges are displayed (Depetris and Pasquini, 2007a). Campos et al. (1999) have recorded a freshwater plume of low salinity and temperature (32, 18 ºC respectively) associated with an increase in RdlP discharge during the El Niño event of 1997, expanding northwards up to 23ºS. Furthermore, during negative AMO phases it was recorded an increasing trend on the precipitations over the SE South America (SESA) and, as a consequence, a concomitant increase in the Rivers Paraná and Uruguay discharge was recorded, while the opposite pattern was observed during positive phases (Chiessi et al., 2009). The aim of this paper is to infer the link between changes in the delivery of terrigenous sediment to the adjacent Atlantic Ocean with recorded hydrological variability of the RdlP. To achieve this, we used sedimentological and geochemical proxies from two sediment cores, which were retrieved from the inner continental shelf off Uruguay and encompass the past 100 AD. Sediment Core GeoB 13813-4 was taken from the inner-shelf “RdlP paleo-valley mudbelt” (Fig. 1;34°44’13’’S, 53°33’16’’W) during research cruise M76/3a (Krastel et al., 2012; Lantzsch et al., 2014). Sediment Core BAR1 was retrieved in the innershelf “Barra del Indio” zone (Fig. 1; 35°03’00’’S, 56°09’00’’W), performed by the Faculty of Sciences, Universidad de la República (Uruguay). For Core GeoB 13813-4, we analyzed the relative abundance of major elements (Ca and Ti) obtained by an X-ray fluorescent sediment core scanner AVAATECH and the Ca/Ti ratio was used to infer continental versus marine influence. This chemical elemental ratio was chosen according to previous successful applications within the Atlantic Ocean (Chiessi et al., 2009; Mahiques et al., 2009; Govin et al., 2012; Bender et al., 2013; Burone et al., 2013). Furthermore, the arithmetic mean grain size distribution was studied from both sediment cores, using the GRADISTAT program (Grain Size Distribution and Statistics Package for the Analysis of Unconsolidated Sediments) version 8 (Blott and Pye, 2001) (Fig. 4). For Core GeoB 13813-4 grain size were obtained by Laser Particle Sizer LS200 and for Core BAR1 were obtained by Malvern Mastersizer 2000 Laser analyser. The chronology from both cores was assessed by 210Pbxs dating (Table 1 and Fig. 2; Appleby, 2001; 2008). For core BAR1 we selected the CRS (Constant Rate Supply) model (which is highly used for estuarine systems), while for GeoB 13813-4 the CFCS (Constant Fluxe: Constant Sedimentation Rate) model was applied (Appleby, 2008; Bernal et al., 2010). In the last case, the decision of using the CF-CS model was due to the lack of a complete 210Pb dataset, which would bring very high sedimentation rates uncertainties (Sanchez-Cabeza and Ruiz-Fernández, 2012). To assess the climatic variability over the past century as inferred from the sediment proxies, we evaluated the climatic indices PDO and Southern Oscillation Index (SOI), of the Joint Institute for the Study of the Atmosphere and Ocean, University of Washington (http://jisao.washington.edu), as well as the AMO from the NOAA (http://www.aoml. noaa.gov/phod/amo_faq.php). We further compared these data with temporal series (encompassing the last century) of the Paraná and Uruguay fluvial discharges (http://www.hidricosargentina. gov.ar/acceso_bd.php), river-flow anomalies were calculated following the approach of Piovano et al. (2004). The generated proxy data were analyzed by running cluster analyses using the stratigraphically constrained Moristia similarity index, in PAST program version 3 (http://folk.uio.no/ohammer/ past/). The generated groups are represented with red lines in figure 3. The sedimentation rate of core GeoB 13813-4 was assumed to be constant with a mean value of 1.3 cm yr-1 (Table 1; Perez Becoña, 2014), while for the sedimentation rate of core BAR1 three groups were observed: 1911-1973; 1976-1984 and 1986-2010. The mean sedimentation rate for the above groups showed an increasing trend from 0.24 ± 0.13 cm yr-1 to 0.31 ± 0.14 cm yr-1 and 0.37 ± 0.10 cm yr-1, respectively. The most positive and stable values of SOI (La Niña events) were recorded during 1910-1970. After 1970, a higher variability and a trend towards more negative values was observed (El Niño events). After the year 2005, very negative SOI values occurred (Fig. 4). PDO showed either negative or close to zero values during the early period 1910-1970 (cold phase). During the subsequent interval, i.e., 1970- 2005, positive values (warm phase) were observed. Regarding with AMO, a positive phase was observed from 1925-1960, followed by a negative phase (1960- 2000), but then a shift to a positive phase until the present was observed. The Paraná river discharge anomalies for the years 1910-1970 were mostly associated with negative values (Fig. 4), while between 1970 and 2010 positive anomalies were documented. Between the years 2000 and 2010, we mostly registered values close to zero. Furthermore, the trends in AMO and SOI indices were negatively associated with the anomalies of both Paraná and Uruguay rivers flows, while PDO index were positive associated with such anomalies. A change in mode polarity observed for PDO and AMO took place by the middle 1970s, in addition to more frequent and intense El Niño events that led to the increased rainfall over SESA (Garreaud et al., 2009). Thus, the increase in rainfall over SESA was concomitant with positive anomalies in the Paraná and Uruguay river discharge rates after 1970 (Camilloni, 2005). In this sense, the Paraná river discharge was 20% higher during the past 30 years than the historical average of the 20th century (Mauas et al., 2008). The results of the cluster analyses groups (Fig. 3) showed a differentiation in both sediment cores that correspons to the beginning of the 1970s, which could be associated with the increasing discharge trend recorded for the Parana and Uruguay rivers over the last three decades. The increase in RdlP discharge led to a higher accumulation rate of terrigenous sediments, as inferred from the high sedimentation rate and mean grain size (BAR1), and the lowest Ca/ Ti ratio (GeoB 13813-4), and explains both the spatial and temporal sedimentological and geochemical variability. Ca/Ti ratio in the RdlP was successfully used to infer marine vs. continental influence, as Ti is associated with a continental RdlP discharge, while Ca is associated with autochthonous marine productivity (e.g. foraminifera, Burone et al., 2013). Thus, the highest continental sediment supply to the inner continental shelf is observed in GeoB 13813-4 after 1970, associated with a decrease in the Ca/Ti ratio (Fig. 4). Regarding with Core BAR1 the grainsize distribution and the sedimentation rate were both associated with the estuarine hydrodynamic changes. After 1970, the highest and most variable sedimentation rate and mean grain size was found, probably associated to an increase in both the Paraná and Uruguay river discharges during the past three decades, while the lowest and more stable sedimentation rates and mean sediment grain size recorded before 1970, is indicating a reduced RdlP freshwater supply to the study area. This study shows that both sediment cores contain a distinct continental runoff record as the result of climatic changes (PDO, AMO and ENOS), which have influenced the precipitation patterns over SESA. Both sites reflect similar responses to these environmental changes for the last 100 yr in continental terrigenous sediment supply from the RdlP watershed towards the inner continental shelf. We conclude that it is possible to assess the temporal? RdlP discharge patterns variability within the estuarine and adjacent oceanic area through the study of terrigenous proxies from sediment cores retrieved within the continental shelf.

El Río de la Plata (RdlP) presenta significativas variaciones naturales (hidrodinámicas y oceanográficas) asociadas a diferentes condiciones climáticas. El propósito de este trabajo es inferir los cambios de aportes continentales de sedimentos y su relación con las variaciones hidrológicas del Río de la Plata, a través del análisis de proxies sedimentológicos y geoquímicos en testigos de sedimentos de la plataforma interna uruguaya que registran los últimos 100 años, aproximadamente. A partir de la datación por 210Pb de dos testigos de sedimentos (GeoB 13813-4 y BAR1) se reconstruyó la geocronología del ambiente, y se relacionó con datos de las forzantes climáticas Pacific Decadal Oscillation, El Niño/La Niña Southern Oscillation, Atlantic Multidecadal Oscillation, y las anomalías hidrológicas de los ríos Paraná y Uruguay. Los valores más positivos y estables del Southern Oscillation Index, los cuales corresponden a fases La Niña, se observan en el periodo correspondiente entre 1910-1970, respecto al resto de la serie, donde se aprecia una mayor variabilidad y una tendencia hacia valores más negativos (eventos El Niño). Se hicieron dendrogramas (clustering) jerárquicos para ambos testigos. Para el testigo GeoB 13813-4, se utilizó la relación Ca/Ti y la granulometría, mientras que para BAR1 se recurrió a variables granulométricas y la tasa de sedimentación. El mayor aporte continental hacia la región de la plataforma adyacente al Río de la Plata registrado a partir del año 1970, podría ser el factor principal de los agrupamientos observados en los clusters para ambos testigos. Las agrupaciones mostraron una diferenciación en la década de 1970, lo que estaría asociado al aumento de los caudales de los ríos Paraná y Uruguay, durante las últimas tres décadas del siglo XX. Por otra parte se observa que la granulometría del testigo BAR1 presentó un mayor tamaño de grano y más variabilidad que en el caso del testigo GeoB 13813-4. También se determinó una mayor acumulación de sedimentos a través del tiempo en el cinturón de barro del Río de la Plata (plataforma continental adyacente), comparado con aquel registrado en la Barra del Indio (límite entre zona intermedia y externa del estuario). Estas diferencias podrían estar relacionadas con la influencia del Río de la Plata, el cual genera un ambiente altamente dinámico sobre la Barra del Indio y un ambiente más estable sobre el cinturón de barro en la plataforma continental.

Diversity and community organization of the benthic macrofauna were investigated along the São Sebastião Channel, northern coast of São Paulo State, Brazil, and related to sedimentary variables and organic load. These important outstanding soft bottom benthic habitats are characterized by their close proximity to sources of human impact. Sampling was undertaken seasonally, using a Van Veen grab (0.1 m²) in 15 oceanographic stations, from November 1993 to August 1994. A total of 392 species were recorded and polychaetes completed nearly 50% of the fauna. Twenty three species were most numerous and frequent and comprised the baseline pool for the area. Sites were classified with respect to sediments in three site-groupings according to Arasaki et al. (2004). The finest-sediment site-group had significantly fewer species than coarser site-groups. The stations locate at the south opening and in the axis of the channel presented sediments with organic matter predominantly of marine origin, indicating the flow of open sea waters across the channel. These places showed also higher values of diversity and species richness. The site-group located along the insular side and in the channel north mouth, stood out for the significantly higher density. Although its relative small area the channel presented species richness similar to that found in the adjacent inner continental shelf. Comparisons between channel and adjacent shelf habitats are addressed in the light of ecological data.

Se estudió la organización y diversidad de la comunidad macrobentónica de fondos blandos del canal de São Sebastião, costa norte del Estado de São Paulo, Brazil, relacionándolo con variables sedimentológicas y carga orgánica del sedimento. Estos fondos marinos importantes para especies bentónicas se caracterizan por encontrarse próximos a fuentes de impacto antrópico. El muestreo se desarrolló estacionalmente a lo largo de un año, en 15 estaciones oceanográficas, con una draga Van Veen (0.1 m²), desde noviembre de 1993 hasta agosto de 1994. Se identificó un total de 392 especies, correspondiendo los poliquetos aprox. al 50% de la fauna. De este total, 23 especies fueron las más abundantes y frecuentes. Las estaciones fueron clasificadas según el sedimento en tres grupos de acuerdo con Arasaki et al. (2004). El grupo de estaciones caracterizado por sedimentos finos presentó significativamente menos especies que los otros dos grupos. Las estaciones localizadas en el extremo sur del canal y en su eje longitudinal presentaron sedimentos con materia orgánica predominantemente de origen marino, reflejando el flujo de aguas del océano abierto a través del canal. Estas estaciones mostraron también mayores valores de diversidad y riqueza de especies. Por otro lado, el grupo de estaciones localizado del lado insular y en la boca norte del canal presentó mayores densidades. A pesar de ser un área relativamente pequeña, el ecosistema del canal de São Sebastião presentó una riqueza de especies semejante a la registrada en la plataforma continental interna adyacente. La comparación de ambos ecosistemas se discute considerando los datos ecológicos disponibles.

Foi realizado um estudo da salinidade e da composição das diatomáceas presentes no sedimento superficial em relação ao conteúdo de proteínas/carboidratos na Baía de Montevidéu e região costeira adjacente. Foram obtidas amostras sazonalmente durante um ano ao longo de um gradiente de impacto ambiental humano, e as condições tróficas foram determinadas através da análise da composição bioquímica da matéria orgânica do sedimento superficial. A coocorrência de espécies de diatomáceas marinhas-salobras, (Actinocyclus curvatulus, Actinocyclus gallicus, Coscinodiscus excentricus, Coscinodiscus radiatus, Hyalodiscus subtilis, Paralia sulcata) e diatomáceas indicadoras de águas doces (Aulacoseira granulata, Aulacoseira italica, Aulacoseira muzzanensis, Actinocyclus normanii, Amphora copulata, Cyclotella meneghiniana, Nitzschia linearis) sugerem condições mixohalinas estuarinas na área de estudo. As estações amostradas dentro da baía, próximas às fontes contaminadoras, apresentam condições hipertróficas apontadas pelos maiores valores de proteínas e pela alta abundância relativa de Actinocyclus normanii e Cyclotella meneghiniana, sendo que ambas espécies são consideradas cosmopolitas e indicadoras de degradação aquática. As concentrações de proteínas e carboidratos, bem como os pigmentos fotossintéticos registrados na região costeira adjacente sugerem condições meso-eutróficas e uma diluição dos níveis de contaminação do interior da baía rumo à região externa. A análise multivariada entre espécies de diatomáceas e parâmetros ambientais indica que o gradiente trófico possui hierarquicamente maior peso que a salinidade na explicação da distribuição das diatomáceas. Os resultados obtidos demonstram um aperfeiçoamento na habilidade de determinar a contaminação orgânica dentro da área de estudo, já que pela primeira vez tanto as variáveis orgânicas quanto os biopolímeros foram introduzidos como ferramenta para a determinação da relação degradação/saúde de uma das mais populosas regiões do Río de la Plata.

A study on sediment surface diatom composition in relation to both protein/carbohydrate content and salinity was carried out in Montevideo Bay and the adjacent coastal zone. Samples were seasonally taken during one year along a human impact gradient, and the trophic conditions were assessed from the biochemical composition of the surface sediment organic matter. The co-occurrence of the marine-brackish (Actinocyclus curvatulus, Actinocyclus gallicus, Coscinodiscus excentricus, Coscinodiscus radiatus, Hyalodiscus subtilis, Paralia sulcata) and freshwater diatom flora (Aulacoseira granulata, Aulacoseira italica, Aulacoseira muzzanensis, Actinocyclus normanii, Amphora copulata, Cyclotella meneghiniana, Nitzschia linearis), suggests myxohaline estuarine conditions in the study area. The sampling stations located within the bay, close to several contamination sources, exhibited hypertrophic conditions as indicated by the highest levels of protein content, but also by the high relative abundances of Actinocyclus normanii and Cyclotella meneghiniana, as both diatom species are very well established cosmopolitan proxies of aquatic degradation. The levels of both protein and carbohydrate content, but also photosynthetic pigments, recorded in the adjacent coastal zone suggest meso-eutrophic conditions as contamination levels from the inner bay might become diluted off shore. Multivariate diatom species-environmental data relationships, indicate that the trophic gradient is hierarchically more important than salinity in explaining the diatom distribution. The present data imply an improvement in our ability of assessing organic contamination in the study area, since both biological and biopolymer variables were introduced for the first time as a tool for assessing the benthic health/degradation in one of the most populated regions of the Río de la Plata.

A estrutura da macrofauna bêntica das regiões entre marés e infralitoral raso na porção nordeste da Baia de Todos os Santos (BTS), nordeste do Brasil, foi investigada durante um período de dois anos. Sua relação com os parâmetros ambientais mensurados foi estudada através de análises estatísticas uni -e multivariadas, sendo os principais padrões de distribuição espacial e temporal relacionados principalmente ao tipo de sedimento e ao conteúdo de três indicadores da matéria orgânica sedimentar (Carbono, Nitrogênio e Fósforo). A macrofauna, composta majoritariamente por anelídeos poliqueta (cerca de 70% do total), apresentou baixa densidade, riqueza de espécies e diversidade, exceto nas estações amostradas nos bancos recifais. Estes se destacam como ambiente peculiar, formado por sedimentos grosseiros, pobres em matéria orgânica e ricos em carbonatos, apresentando fauna abundante e diversificada. A região entre marés e os locais rasos adjacentes à refinaria RLAM são formados por sedimentos compostos principalmente por areia fina e baixo conteúdo orgânico e constituem ambiente instável, com poucas espécies altamente dominantes, como Armandia polyophthalma e Laeonereis acuta. Em outras regiões da BTS, onde dominam os sedimentos pelíticos, densidade e diversidade foram muito baixas, especialmente nas proximidades da refinaria. Aqui, os indicadores biológicos apresentaram seus mais baixos valores, sendo as estações mais próximas (4 e 7) algumas vezes azóicas. A região adjacente de Caboto, inicialmente considerada como controle, apresentou baixa densidade, porém valores médios para diversidade, o que indica ser este ambiente relativamente menos perturbado. Foi possível identificar a existência de 5 grupos com padrões estruturais próprios (entremarés; bancos recifais; infralittoral pelitico; sedimentos mistos; Caboto), que parecem estar relacionados principalmente às características físicas e químicas do sedimento.

Structure of intertidal and subtidal benthic macrofauna in the northeastern region of Todos os Santos Bay (TSB), northeast Brazil, was investigated during a period of two years. Relationships with environmental parameters were studied through uni-and multivariate statistical analyses, and the main distributional patterns shown to be especially related to sediment type and content of organic fractions (Carbon, Nitrogen, Phosphorus), on both temporal and spatial scales. Polychaete annelids accounted for more than 70% of the total fauna and showed low densities, species richness and diversity, except for the area situated on the reef banks. These banks constitute a peculiar environment in relation to the rest of the region by having coarse sediments poor in organic matter and rich in biodetritic carbonates besides an abundant and diverse fauna. The intertidal region and the shallower area nearer to the oil refinery RLAM, with sediments composed mainly of fine sand, seem to constitute an unstable system with few highly dominant species, such as Armandia polyophthalma and Laeonereis acuta. In the other regions of TSB, where muddy bottoms predominated, densities and diversity were low, especially in the stations near the refinery. Here the lowest values of the biological indicators occurred together with the highest organic compound content. In addition, the nearest sites (stations 4 and 7) were sometimes azoic. The adjacent Caboto, considered as a control area at first, presented low density but intermediate values of species diversity, which indicates a less disturbed environment in relation to the pelitic infralittoral in front of the refinery. The results of the ordination analyses evidenced five homogeneous groups of stations (intertidal; reef banks; pelitic infralittoral; mixed sediments; Caboto) with different specific patterns, a fact which seems to be mainly related to granulometry and chemical sediment characteristics.

In Uruguay, as well as in other regions of the world, IAS cause negative impacts on natural and managed ecosystems. The use of databases is a helpful tool to elaborate different strategies for prevention and control, and to develop policies and scientific analyses related to IAS. The database of IAS in Uruguay (InBUy) was developed during two time periods (2006-2007 and 2009-2010). It currently contains information on 33 specialists of different taxonomic groups, 14 research projects, 185 references, 351 species and 4,715 records, with vascular plants having both the highest number of species and records. Among vascular plants, herbaceous life forms are the most strongly represented, followed by trees and shrubs. Within animals, the fishes and mollusks are the most important groups. Analysis of the native distribution areas of IAS showed that most are indigenous from Europe, followed by Asia and Oceania. Data showed that introductions of IAS into Uruguay are mainly intentional (67%), so efforts should be focused on policies and rules in order to control the entrance of exotic organisms and prevent new invasions. The geography of the compiled dataset shows the main impact is along the coastline, where the highest exotic species richness and records occurs, and also the most biological invasions. The InBUy database is up-to-date and has successfully contributed to the creation of an official IAS list for Uruguay and both a National and a Coastal Geographic Information System. It has also been used for developing consciousness about this important threat to biodiversity, at both national and regional scales.

En Uruguay, al igual que en otras partes del mundo, las EEI han causado impactos negativos sobre los sistemas naturales y productivos. El uso de bases de datos a nivel mundial es una herramienta útil para elaborar estrategias de prevención y control, y para desarrollar políticas y análisis científicos en relación a las EEI. La base de datos de EEI en Uruguay (InBUy) fue desarrollada durante dos períodos (2006-2007 y 2009-2010). Actualmente contiene información de 33 especialistas de diferentes grupos taxonómicos, 14 proyectos de investigación, 185 referencias bibliográficas, 351 especies y 4715 registros, donde las plantas vasculares presentan el mayor número de especies y registros. Entre las plantas vasculares, las herbáceas son la forma de vida más representada, seguida por árboles y arbustos. Dentro de los animales, los peces y moluscos son los grupos más importantes. El origen geográfico de las EEI muestra que la mayoría son nativas de Europa, seguido por Asia y Oceanía. Los datos recabados muestran que la introducción de EEI a Uruguay es mayormente intencional (67%), por tanto los esfuerzos deberían ser focalizados en políticas y reglamentaciones para controlar el ingreso de organismos exóticos y prevenir nuevas invasiones biológicas. Por otra parte, los datos muestran un impacto mayor sobre los ambientes costeros, donde fue registrado el mayor número de especies y registros, así como el mayor número de invasiones biológicas. Hasta la fecha, la base de datos InBUy ha contribuido exitosamente en la conformación de una lista oficial de EEI para Uruguay, y en la construcción de un Sistema Geográfico de Información Nacional y Costero. Asimismo, ha contribuido a la concientización a través de políticas de divulgación acerca de esta importante amenaza sobre la conservación de la biodiversidad, tanto a escala nacional como regional.

Foram realizadas análises de matéria orgânica, carbono orgânico, nitrogênio, enxofre e granulometria utilizando-se 101 amostras de sedimentos superficiais na Enseada de Ubatuba, SP, com a finalidade de investigar a origem e distribuição espacial da matéria orgânica, sua origem e as relações existentes entre seus componentes químicos. O material foi coletado com amostrador tipo "corer'', em profundidades compreendidas entre 1 e 15m, a bordo do B/Pq "Veliger II'', em 5 coletas a cada dois meses. As amostras foram analisadas estatisticamente através de correlação linear de Pearson, regressão e análise de componentes principais (PCA). Foram obtidas boas correlações entre a matéria orgânica e as frações finas do sedimento. O PCA revelou a existência de duas regiões principais dentro da enseada, que refletem diretamente as condições hidrodinâmicas locais. Foi estabelecida uma equação linear simples para obtenção de boas estimativas de carbono orgânico, a partir de dados de matéria orgânica obtida por técnicas de calcinação. Considerando-se a rapidez e o baixo custo das análises de matéria orgânica quando comparadas às de carbono orgânico, o presente método mostrou-se útil em análises de rotina ou quando se fazem necessárias avaliações imediatas do conteúdo de matéria orgânica em ambientes impactados.

Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were performed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial distribution of organic matter, its origin and the relationships among its components. The samples were obtained with a manual corer, from water depths between 1 and 15m during 5 cruises of the R/V "Veliger II'', two months apart. Pearson correlation, regression and Principal Component Analysis (PCA) statistical methods were used to analyze the data. Strong correlations between organic matter and fine sediment fractions were obtained. The PCA revealed at least two main sample groups that reflect the different environmental conditions prevalent in the bay. There is a simple linear relationship between organic carbon content and the organic matter content determined by the calcination technique. Taking into account that the analysis of organic matter content is less expensive and less time consuming than the analysis of organic carbon, the present method of estimation can be useful when fast evaluation of the organic carbon content is needed for samples from similar environments.