Anthropogenic sound has profoundly changed the acoustic environment of aquatic habitats, with growing evidence that even a short exposure to man-made sound sources can negatively affect marine organisms. Marine invertebrates have received little attention regarding their responses to anthropogenic sound, despite their pivotal role in marine ecosystems, and preliminary evidence of their sensitivity. In this thesis, I critically review the methods used in studies investigating the effects of anthropogenic noise on marine invertebrates. I identify methodological trends that have developed along the timeline of this topic, and use this information to suggest three research strategies to further the development of research in this field. From this review, current knowledge gaps are identified, and two main routes to address them are taken in this thesis. Firstly, to address the shortage of particle motion data in anthropogenic sound literature, two new low-cost and easily accessible particle motion sensors were developed and tested, one of them at 0.1% of the cost of currently commercially available models. These sensors will allow the measurement and reproduction of the sound fields experienced by marine invertebrates in bioacoustic research, even when research budgets are tight. Particle motion is the main sound component detected by invertebrates, yet neglected in many aquatic bioacoustical studies. Secondly, to expand on the comparably small quantity of research investigating the effects of anthropogenic sound on marine invertebrates, a series of controlled laboratory experiments were conducted. Two commercially and ecologically important model species were chosen, the blue mussel Mytilus edulis, representing sessile benthic invertebrates, and the European lobster Homarus gammarus, representing mobile benthic invertebrates. Experiments on M. edulis were conducted taking a mechanistic, integrative approach to investigate the effects of sound on multiple levels of biological organisation, including biochemistry, physiology, and behaviour. The ultimate aim was to understand the underlying drivers behind, and interactions between, responses. Comet assay analysis of haemocytes and gill cells demonstrated a significant six-fold higher single strand breakage in the DNA of cells of mussels exposed to ship-noise playback, compared to those kept under ambient conditions. Superoxide dismutase analysis did not identify an excess of superoxide ions, and glutathione, and glutathione peroxidase assays showed no increase in either glutathione or glutathione peroxidase. TBAR assays however revealed 68% more thiobarbituric acid reactive substances, indicating lipid peroxidation in the gill epithelia of noise exposed specimens. Algal clearance rates and oxygen-consumption rates of noise-exposed mussels were significantly lower (84% reduction and 12% reduction respectively), than those of control animals, while valve gape was significantly (60%) wider. This seemingly converse reaction indicates a shock response in mussels with the onset of noise exposure. Finally, at the genetic level, heat shock protein 70 expression was investigated, but no change was identified during noise exposure. Investigation into the noise induced behavioural responses of H. gammarus suggests seasonal differences in behaviour, using movement as a metric, in response to anthropogenic noise playbacks. During both summer and winter exposures, lobsters spent most time away from the highest noise area (98% of the observed time in summer and 78% in winter). The observed seasonal differences in the time spent in the highest noise area (2% in summer and 22% in winter) could be linked to the lobsters' requirement for shelter during winter. This requirement seems to have had a stronger influence over the animals' behaviour than any desire to avoid high noise levels. The information generated in this thesis can be used by researchers working in the field of marine sound to develop well rounded studies exploring the effects of sound on not only marine invertebrates but other faunal groups as well. The construction details provided to produce low cost particle motion sensors, will allow bioacoustic researchers to easily include particle motion measurements in all future studies investigating the effects of sound on fish and invertebrates. The results of the conducted mussel and lobster experiments evidence how multiple aspects of invertebrate biology can be affected by noise. The observed impacts on both sessile and mobile life forms highlight that the effects of noise cannot be fully understood before a wide range of species with different biological and ecological traits have been studied. The integrative approach to noise research used here can serve as a model for other species, and the results pooled to inform governments and industry of the effects of anthropogenic noise in the marine environment.

The chemical study of three New Zealand marine organisms is described, along with a survey of the chemistry and biological activity of eighty-five marine organisms collected from New Zealand waters. The study of the New Zealand marine bryozoan Pterocella vesiculosa has resulted in the isolation of three new compounds; pterocellin H, pterocellin I and 1-methyl-5-bromo-8-methoxy-β-carboline. These compounds were characterised using high resolution mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectroscopy and X-ray crystallography. The biological activity of these compounds was investigated and a discussion of the results including a comparison with the activity of closely related compounds is also presented. The crude extracts of eighty-five marine organisms were surveyed to establish their biological activity and chemical constituents. The results of this study indicated which species had interesting biological activity. The chemical survey allowed geographical and intra-species comparisons of chemical constituents between samples, as well as potentially indicating the presence of known secondary metabolites. For the Pterocella vesiculosa samples the survey methodology clearly illustrated the presence of pterocellins A and B. Two marine organisms were chosen for further investigation based on their biological activity and chemical survey results. Bioactivity directed isolation procedures yielded no new compounds from the organisms. The sterol composition of these species is also presented.

The occurrence of unresolved complex mixtures of hydrocarbons (UCMs) in the aliphatic fraction of marine sediments and organisms from areas impacted by petroleum hydrocarbons is well documented and widely accepted as an indication of fossil fuel contamination. In contrast, the presence of an aromatic UCM is often ignored and environmental concentrations of aromatic UCM hydrocarbons in marine biota and sediments are rarely reported. The aims of this study were to establish the quantitative significance of aromatic UCMs in environmental samples and to assess the toxicological significance of both aliphatic and aromatic UCMs. A reproducible method was developed and validated for the analysis and quantification of petroleum hydrocarbons in mussel (Mytilus edulis) tissue. Emphasis was placed upon development of a method which minimized losses of more volatile, lower molecular weight, toxicologically significant hydrocarbons, without compromising recovery of higher molecular weight compounds which are useful for source identification in environmental monitoring schemes. Analysis of mussels from a small number of U. K. coastal locations indicated that aromatic hydrocarbon UCMs may form a significant proportion (ca 20 %) of the total hydrocarbon body burden of mussels from areas contaminated with petroleum hydrocarbons. Aromatic UCM hydrocarbons were not observed in mussels from relatively uncontaminated areas but concentrations of 430 μg g'' (dry wt tissue) were measured in mussels from heavily impacted areas. Aliphatic UCM concentrations ranged from 7- 3445 μg gg' (dry wt tissue). For the purposes of toxicological studies, a low molecular weight model aliphatic UCM hydrocarbon, 4-propyloctane (4-PO) was synthesised. Two low molecular weight model aromatic hydrocarbons 7- cyclohexyltetralin and 7-cyclohexyl-l-propyltetralin were also synthesised using a modification of the Haworth synthesis. All three target compounds and synthetic intermediates were characterised by NMR, MSandIR. Exposure of M. edulis to 4-PO caused a significant reduction in mussel ciliary feeding activity indicating that 4-PO was indeed toxic as measured by this bioassay. The demonstrable narcotic activity of 4-PO is presumably related to the greater aqueous solubility of branched hydrocarbons compared with similar straight chain hydrocarbons. Further experiments investigating the effect of 4- PO over exposure periods up to 120h provided a unique and detailed insight into the relationship between concentration of toxicant in the gills of M. edulis and observed feeding rate. The established method of mussel feeding rate determination was modified in light of this relationship to produce an " improved rapid and reproducible screening technique. Both of the model aromatic UCM hydrocarbons were also found to be toxic to mussel ciliary feeding activity. This appears to be the first report of investigations into the toxicity of the aromatic UCM and suggests that previous studies have ignored an environmental burden of toxicological significance. Estimates of the tissue effective concentration (TEC50) for the model UCM hydrocarbons gave comparable values with those reported for the effect of other narcotic hydrocarbons upon mussel feeding rate, providing support for the theory that non-specific narcosis occurs at a relatively constant tissue concentration of toxicant. The demonstrated narcotic activity of each of the three model UCM hydrocarbons has extended the molecular weight range of narcotic hydrocarbons studied to date. The results presented herein suggest that a small proportion of low molecular weight aliphatic UCMs and perhaps a greater proportion of aromatic UCMs are of toxicological significance.

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 42-47).

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf [64-67]).

The decrease of biological diversity from low latitudes near the equator towards high latitudes is one of the most fundamental patterns noted in ecology. These trends have been the subject of numerous terrestrial and marine studies and have caused the proposal of several explanatory hypotheses. No single hypothesis has adequately accounted for these observed trends. Furthermore, large-scale patterns are frequently modified by processes acting at meso- to small-scales. It is imperative to understand the interaction of these processes to elucidate the mechanisms controlling the structure of intertidal assemblages. The main aim of this thesis was to test the influence of multiple processes at a range of spatial scales on biogenic engineers. Biogenic engineers, such as macroalgae, have been reported to be strongly influenced by processes such as grazing, biogeography and upwelling and subsequent effects are expected to be linked to their associated assemblages. I used infaunal assemblages associated with macroalgae as a model system to understand the interactive effects of meso-scale upwelling in conjunction with large-scale factors (regional and biogeographic). Three species of macroalgae, Hypnea spicifera, Champia lumbricalis and Bifurcaria brassicaeformis, inhabiting different but overlapping home ranges were used in this study. Smaller scale, physical attributes and the associated fauna of these algal species were compared. The effects of meso- to large-scale physical gradients on marine organisms have been investigated in many instances and resultant gradients in physical variables observed. This study was undertaken to investigate morphological trends exhibited by Hypnea spicifera and Champia lumbricalis to compare possible similarities between coastlines and to determine if inferred meso- to large-scale processes influence physical trends in a similar manner despite the coastlines being affected by different hydrodynamic processes. The macroalgae were located in two distinctly different upwelling regimes, Hypnea spicifera on the east and south coasts and Champia lumbricalis on the west coast. Upwelling (delivery of nutrients and primary production) was not found to be an important factor in determining the physical characteristics of macroalgae but there were clear patterns linked to latitude. Mean percentage cover of Hypnea spicifera was positively correlated with distance along the east and south coasts. Mean mass and mean surface area of H. spicifera were, however, negatively correlated with distance from Port St Johns. Mean frond length showed a negative trend but this relationship was not statistically significant. On the west coast, there was a significant increase in mean frond length from north to south for Champia lumbricalis. Mean surface area and mean mass of C. lumbricalis exhibited non-significant negative trends from north to south while there was a non-significant positive trend for mean percentage cover. Following the “Productivity Hypothesis”, these patterns from north to south along the coastlines of South Africa could have important implications for biodiversity associated with these algae. Many previous studies have focussed on the effects of upwelling on species (i.e. effects of nutrients and temperature) but have failed to separate this effect from large scale effects such as biogeography and latitudinal gradients. I tested the influence meso-scale upwelling, large-scale biogeographic processes and latitudinal gradients with two different species of macroalgae one on the east and south coasts of South Africa and the other on the west coast. Hypnea spicifera inhabits the east and south coasts of South Africa spanning two biogeographic provinces and is generally affected by relatively weak upwelling, whereas Champia lumbricalis inhabits the west coast spanning one biogeographic province which is subjected to intense persistent upwelling year round. Within the east and west coast biogeographic provinces there are, however, regions with both upwelling and non-upwelling. On the east and south coasts, entire assemblages differed significantly among the three Regions (St Lucia, Port Alfred and Knysna, while assemblages between upwelling/non-upwelling areas were not different. Assemblages on the different shores differed significantly from each other. There were no significant effects of region or upwelling for the number of individuals of Crustacea or Polychaeta, while Mollusca showed a significant effect of region. The number of individuals of other taxa showed a significant interaction of region and upwelling. Region had a significant effect on number of species of molluscs and other taxa, while there was no effect for either region or upwelling for the Crustacea or Polychaeta. In general different factors were shown to be important (region and shore) while upwelling was rarely important. On the west coast assemblages associated with C. lumbricalis were not influenced by region or upwelling but there were significant differences between shores. Region, upwelling ad shore did not affect number of individuals. There was a significant interaction of region and upwelling for the number of species of crustaceans, while numbers of species of Mollusca, Polychaeta and other taxa showed no effects. In general, regional factors strongly influenced most organisms, while upwelling played a minor role. Hypotheses about differences between upwelling and non-upwelling regions in terms of species abundances and composition due to the input of cold nutrient rich water were not supported. A link between the effects of larger-scale biogeographic factors and their influence on habitat forming taxa and the resultant effects on associated infauna would be a likely explanation for the patterns observed in this study. Diversity of assemblages is known to be influenced by the structural complexity of a habitat, increasing complexity increases the amount of available niches therefore potentially increasing the number of species found within that habitat. Three species of macroalgae, Hypnea spicifera, Champia lumbricalis and Bifurcaria brassicaeformis were selected on the basis of being structurally similar and having their distributional ranges overlap in order to elucidate the effects of structure and macroalgal species on associated assemblages. Hypnea spicifera is different in terms of surface area and biomass from Champia lumbricalis and Bifurcaria brassicaeformis. Assemblages of species found on the three rhodophytes showed both shore and the species of alga had significant effects on composition. Only numbers of individuals of molluscs were affected by the species of alga. Crustacea and Polychaeta showed an interaction of the species of alga with shore. In the case of this study, it is likely that the three species of macroalgae mitigate biological stressors such as predation and physical stressors such as wave exposure and desiccation. In general, meso-scale upwelling is suggested to be marginalised when considering the structuring of assemblages associated with macroalgae, while large scale biogeography has more of an influence. Within shores, assemblages were also strongly influenced by smaller-scale factors such as differences in the structure and species of alga. This study indicates the importance of investigating patterns across a range of spatial scales to gain a comprehensive understanding of factors influencing intertidal organisms.

Com o objetivo de aplicar e avaliar a viabilidade de uso dos métodos disponíveis com organismos marinhos, no controle da toxicidade de efluentes líquidos que são lançados em ambientes estuarinos, foram realizados testes de toxicidade aguda com os crustáceos Mysidopsis juniae, Artemia sp, Temora stylifera e Acartia IiIljeborgi e testes de toxicidade crônica de curta duração com o equinodermo Lytechinus variegatus, utilizando-se os efluentes industriais de uma indústria siderúrgica, COSIPA e uma fábrica de fertilizantes, ULTRAFÉRTIL/JARDIM SÃO MARCOS, ambos lançados no estuário do Rio Cubatão. Dentre os organismos-testes utilizados, para avaliação do efeito tóxico agudo, o misidáceo M. juniae foi o mais sensível para ambos os efluentes, sendo que Artemia sp foi o menos sensível. Testes de toxicidade crônica com L. variegatus também se mostraram bastante úteis para avaliação de efeitos subletais. Os efluentes analisados apresentaram grande variabilidade durante o período de estudo, o que foi evidenciado através do cálculo do coeficiente de variação para testes com M. juniae. Foi avaliado, também, o efeito da salinidade sobre a sensibilidade dos crustáceos M. juniae e Artemia sp a agentes químicos (zinco e DSS) e aos efluentes industriais. A salinidade não interferiu significativamente nos resultados observados, com exceção de um experimento realizado a 15x10-3 com Artemia sp, com o efluente da COSIPA. Verificou-se, ainda, o possível efeito da utilização de salmoura obtida através dos processos de congelamento e evaporação da água do mar, sendo que o primeiro processo foi indicado para salinização de efluentes. / Acute toxicity tests with the crustaceans Mysidopsis juniae, Anemia sp, Temora stylifera e Acartia lilljeborgi and short-term chronic toxicity test with the echinoderm Lytechinus variegatus were conducted with the objective of evaluating the appropriateness of their application for the control of liquid effluents disposed off in estuarine environments. Effluents of a siderurgic industry, COSIPA, and of a fertilizer plant, ULTRAFÉRTIL/JARDIM SÃO MARCOS, were used. Both are discharged into the estuary of Cubatão river. The test with M. juniae was the most sensitive of the acute methods, for both kinds of effluents, while that with Artemia sp was the least sensitive. Chronic toxicity test with L. variegatus showed to be very useful for the evaluation of sublethal effects. The different effluent samples of both industries had great variability in their toxic effects, along the different sampling periods, as was evidenced by the high coefficient of variation for tests with M. juniae. The effects of salinity on the sensitivity of M. juniae and Artemia sp to chemicals (zinc and DSS) and to the industrial effluents, was evaluated. Salinity did not signifieantly affect the test results, except for the experiment conducted at 15x10-3 with Artemia sp, with the effluent from the siderurgic industry. The possible effect of the use of brine, obtained by freezing or evaporating sea water, was also analyzed. Freezing was the recommended procedure to salinize effluents.

Orientadores: Clarice Weis Arns, Luciana Konecny Kohn / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T21:48:22Z (GMT). No. of bitstreams: 1 Bastos_JulianaCristinaSantiago_M.pdf: 1673040 bytes, checksum: 1234828d961406573d21b2476f1f1800 (MD5) Previous issue date: 2013 / Resumo: O vírus da Hepatite C (família Flaviviridae, gênero Hepacivirus) é causador de infecções crônicas em humanos, que podem evoluir para quadros de cirrose hepática e carcinoma hepatocelular. Até o momento, não há vacina disponível contra essa infecção e o tratamento disponível é caro, tem eficácia limitada e gera uma vasta gama de efeitos secundários, o que dificulta a continuidade do tratamento. Como esse vírus não replica eficientemente em cultura de células e em animais, o vírus da diarréia viral bovina é utilizado como modelo substituto para ensaios de avaliação de atividade antiviral e em ensaios de mecanismo de ação. A partir de invertebrados e micro-organismos marinhos, foram preparados extratos e frações, e algumas substâncias foram isoladas para a avaliação da sua possível atividade antiviral. Dos 422 testados, 5% foram considerados promissores e, destes, 20% mostraram-se ativos apresentando uma proteção de mais de 97% às células frente ao vírus. Os melhores resultados foram obtidos dos extratos produzidos a partir das amostras de esponjas Hyrtios sp. (BA07ES-56: PI=99%, IS=25), Aaptos sp. (BA07ES-59: PI=99%, IS=8,25) e de bactérias Bacillus sp. (555: PI=98%, IS>18; 584: PI=98%, IS=27) isoladas da esponja Petromica citrina. Os extratos e compostos promissores foram capazes de atuar em diversas etapas do ciclo replicativo viral (adsorção, penetração, etapas intracelulares do ciclo replicativo e também inativação da partícula viral), levando à sua interrupção quase completa nas condições analisadas. Desse modo, diversas substâncias presentes nesses organismos estudados são ativas e podem levar ao desenvolvimento de fármacos que garantam uma terapia alternativa para o tratamento da hepatite C / Abstract: The Hepatitis C virus (family Flaviviridae, genus Hepacivirus) causes chronic infections in humans, which can develop to liver cirrhosis and hepatocellular carcinoma. This represents a major public health problem worldwide. To this moment, there is no vaccine available against this infection and the treatment available is expensive, has limited efficacy and generates a wide range of side effects, making it difficult to continue the treatment. All this reflects the need to seek new agents with antiviral action against this virus. As this virus does not replicate efficiently in cell culture and in animals, bovine viral diarrhea virus is used as a surrogate model for screening assays of antiviral activity, and mechanism of action assays. From marine invertebrates and micro-organisms isolated from them, extracts and fractions were prepared, and substances were isolated for assessment of their possible antiviral activity. Of the 422 tested, 5% were considered promising, and of these, 20% were active presenting a protection percentage of more than 97%. The best results were obtained from the extracts produced from the samples of sponge Hyrtios sp. (BA07ES-56: IP=99%, SI=25), Aaptos sp. (BA07ES-59: IP=99%, SI=8,25) and bacteria Bacillus sp. (555: IP=98%, SI>18; 584: IP=98%, SI=27) isolated from the sponge Petromica citrina. The promising extracts and compounds acted in several stages of viral replicative cycle (adsorption, penetration, intracellular steps of the replicative cycle and also inactivation of the viral particle). Thus, various substances are active and may lead to the development of drugs which ensure an alternative therapy for the treatment of hepatitis C / Mestrado / Microbiologia / Mestra em Genética e Biologia Molecular

Orientador: Solange Cadore / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T10:17:48Z (GMT). No. of bitstreams: 1 Torres_DaianePlacido_D.pdf: 1567651 bytes, checksum: 12e05a873e79daebed7a38f7d275aec6 (MD5) Previous issue date: 2013 / Resumo: A primeira etapa deste trabalho consistiu no desenvolvimento e na validação de um método para a determinação de mercúrio total em peixe e camarão por espectrometria de absorção atômica com decomposição térmica/amalgamação (TDA AAS). O método foi validado segundo legislações nacionais e internacionais, específicas para gêneros alimentícios, e utilizado para a análise de amostras de peixe e camarão, atendendo o Plano Nacional de Controle de Resíduos e Contaminantes (PNCRC), do Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Para tanto, foram avaliadas a linearidade, efeitos de matriz/ interferências, limites de detecção e de quantificação, precisão (repetitividade e reprodutibilidade intra-laboratorial), robustez e exatidão (recuperação). Na segunda parte deste trabalho, desenvolvida no período de doutorado sanduíche na Universidade de Aberdeen, na Escócia, buscou-se avaliar as características da exposição de caranguejos a mercúrio inorgânico ou metilmercúrio, com ou sem co-exposição a selenato, através da dieta, com a finalidade de avaliar o efeito do selênio em neutralizar a toxicidade do mercúrio, bem como o efeito da razão molar Hg:Se nas dietas e tecidos dos caranguejos expostos. Para os caranguejos expostos a mercúrio inorgânico, a acumulação do mesmo foi estatisticamente confirmada (p-valor < 0,05 para a comparação dos tecidos dos caranguejos expostos com aqueles dos caranguejos controle) no hepatopâncreas, músculo da carapaça, guelra e coração, ao passo que para o caso da co-exposição a selênio, a acumulação de mercúrio foi significativa somente no coração. Diferentemente, quando se considera a exposição a metilmercúrio, a acumulação de mercúrio foi estatisticamente significativa no músculo da carapaça e das pernas, hepatopâncreas, guelra, coração e testículo/ovário. Entretanto, para a co-exposição a selênio, a acumulação de mercúrio foi somente significativa no músculo da carapaça e guelra. Desta forma, o acúmulo de mercúrio e as interações Hg-Se no hepatopâncreas, coração e músculo dos caranguejos foram altamente significativas para as exposições às espécies de Hg sem co-exposição a Se. Assim, a co-exposição a selênio através da dieta desempenhou um papel importante na redução do impacto da toxicidade das espécies de mercúrio investigadas neste trabalho, mostrando uma mudança nos padrões de absorção e acumulação desses compostos nos tecidos dos caranguejos. / Abstract: In the first step of this work the development and validation of a method for the determination of total mercury in fish and shrimp by thermal decomposition/ amalgamation atomic absorption spectrometry (TDA AAS) was accomplished. This methodology, validated according to national and international foodstuff protocols, has been employed for the analysis of fish and shrimp from the National Residue Control Plan, from the Ministry of Agriculture of Brazil. To comply with the international protocols, linearity, interferences/ matrix effects, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness and accuracy (recovery) of the method have been evaluated. The second step of this work, developed during a period of Sandwich Ph.D. at the University of Aberdeen, Scotland, aimed to evaluate the features between dietary inorganic mercury or methylmercury, with or without selenate co-exposure, in order to examine dietary selenium¿s role in counteracting mercury toxicity as well as the effect of Se:Hg molar ratio in the diets and tissues of exposed crabs. For the crabs exposed to inorganic mercury, the accumulation was statistically confirmed (p-value < 0.05 for the comparison of the tissues from the exposed crabs to those from the control crabs) in the hepatopancreas, muscle from thorax, gill and heart, whereas for the co-exposure to selenium, the accumulation of mercury was significant only in the heart. In contrast, when considering the methylmercury exposure, the Hg accumulation was statistically significant in the muscle from thorax and legs, hepatopancreas, gill, heart and testis/ovarium. However, for the co-exposure to selenium, the Hg accumulation was only significant in the muscle from thorax and gills. Therefore, the accumulation of Hg and the Hg-Se interactions in the hepatopancreas, heart and muscle of the crabs were highly significant for the exposures to Hg species without co-exposure to Se. Thus, the dietary exposure to Se played a very important role reducing the impact of the toxicity of the Hg species investigated in the present work, showing to change their toxicokinetics and toxicodynamics in crabs tissues, and in consequence their uptake and accumulation patterns. / Doutorado / Quimica Analitica / Doutora em Ciências

O consumo de peixes e frutos do mar está associado à manutenção de uma dieta saudável em função da sua proteína de elevado valor biológico, da presença de ácidos graxos poli-insaturados e de importantes nutrientes como selênio, ferro, cálcio e fósforo. No entanto, esses organismos representam uma importante fonte de elementos-traço contaminantes para os seres humanos em função da bioacumulação desses elementos que também podem biomagnificar ao longo da cadeia alimentar. Apesar da ocorrência natural de elementos-traço no meio ambiente, sua concentração nos ecossistemas costeiros tem aumentado drasticamente em função de atividades antropogênicas, fazendo com que os organismos marinhos atuem como um elo da contaminação ambiental à contaminação humana. O presente trabalho avalia a concentração de elementos-traço em diferentes tecidos de organismos marinhos sob dois aspectos: (1) o risco alimentar associado ao consumo das espécies analisadas e (2) a bioacumulação dos elementos em diferentes tecidos. Para isso foram analisadas três espécies de peixes comercializadas na cidade de Santos (SP): Sphyraena guachancho (bicuda), Priacanthus arenatus (olho de cão) e Genidens genidens (bagre) e três espécies coletadas em diferentes pontos do Sistema Estuarino de Santos (SP): Callinectes danae (siri azul), Mytella guyanensis (mexilhão) e Mugil curema (parati). O hábito alimentar foi o principal critério para seleção das espécies. O risco alimentar, calculado pelo Índice Provisório de Risco (PHI) e pelo Índice Provisório de Risco Total (PTHI), apresentou valores elevados para Sphyraena guachancho (espécie piscívora) e para peixes e siris coletados no Sistema Estuarino de Santos. A bioacumulação foi associada à espécie, tecido e tipo de elemento avaliado. A espécie piscívora apresentou elevada concentração de Ba, Hg e Ag no tecido muscular, indicando a potencial biomagnificação desses elementos ao longo da cadeia alimentar. Genidens genidens, espécie detritívora, apresentou elevada concentração de Ba, Cd e Pb na nadadeira, possivelmente associado às estratégias de detoxificação da espécie, por meio da imobilização desses contaminantes no esporão ósseo. / The consumption of fish and seafood is associated with the maintenance of a healthy diet due to its protein of high biological value, the presence of polyunsaturated fatty acids and important nutrients as selenium, iron, calcium and phosphorus. However, these organisms represent an important source of contaminant trace elements for humans due to the bioaccumulation of these elements in tissues that can also biomagnify along the food chain. Despite the natural occurrence of trace elements in the environment, its concentration in coastal ecosystems has increased dramatically as a result of anthropogenic activities, causing marine organisms to act as a link between environmental and human contamination. The present work evaluates the concentration of trace elements in different tissues of marine organisms under two aspects: (1) the food risk associated with the consumption of the species analyzed and (2) the bioaccumulation of the elements in different tissues. Three species of fish commercialized in the city of Santos (SP) were analyzed: Sphyraena guachancho (bicuda), Priacanthus arenatus (dog eye) and Genidens genidens (catfish) and three species collected at different points of the Santos Estuarine System (SP): Callinectes danae (blue crab), Mytella guyanensis (mussel) and Mugil curema (parati). The eating habit was the main criteria for selection of the species. The food risk, calculated by means of the Provisional Hazard Index (PHI) and the Provisional Total Hazard Index (PTHI), presented high values for the piscivorous species Sphyraena guachancho and for fish and crabs collected in Santos Estuarine System. The bioaccumulation was associated with the species, tissue and type of element evaluated. The piscivorous species had a high concentration of Ba, Hg and Ag in muscle tissue, indicating the potential biomagnification of these elements along the food chain. Genidens genidens, a detivorous species, presented a high concentration of Ba, Cd and Pb in the fin, possibly associated with the detoxification strategies of the species, through the immobilization of these contaminants in the bone spur.