Resumo em Inglês:

Abstract Oceanic islands are important areas of environmental, social, economic, and scientific interest. Therefore, it is essential to identify pollutants in these environments, including large (1 mm to ≤ 5 mm) and small microplastics (SMP) (1 µm to ≤ 1 mm). Here, SMP were identified and characterized in the windward (WW) and leeward (LW) beaches of Fernando de Noronha Island. Samples were collected from 900 cm2 quadrants on the strandline of 15 sandy beaches and were sieved through stainless steel sieves with 1 mm mesh. The SMP were characterized according to their shape, colour, and size. Synthetic fibres and fragments were identified, and synthetic fibres were predominant. Statistical differences were not found between the WW and LW beaches (160.0±137.5 particles m-2 and 128.0±84.3 particles m-2, respectively; Mann-Whitney U test: U=198.5; p=0.81) in relation to the total amount of SMP deposited on the beaches. Also, both types/shapes were present in the two groups of beaches (Friedman’s test, X2r=6.09; p=0.91). The environmental forcings controlling the transport and potential deposition of synthetic fibres may have been different from those acting on fragments that more resembled the grains of sand in the beaches. Although it is difficult to prevent allochthonous sources of SMP at the small scale, management actions on the island are mandatory to prevent autochthonous sources.

Resumo em Inglês:

ABSTRACT The aim of the present study was to analyse the composition and spatiotemporal distribution of the benthic macrofauna in the estuary of the Perizes River (state of Maranhão, Brazil). Biological and environmental samples were collected at five sampling sites along the estuary during six campaigns covering the months of September, October and November 2016 (dry period) and February, March and April 2017 (wet period). Sampling was performed with a van Veen grab sampler (682cm2). Environmental variables as temperature, pH, salinity, dissolved oxygen, saturation and water transparency were measured and related to the biological data at each sampling site. After collection the samples were sieved through a 0.5 mm mesh and the organisms fixed in a 10% formaline solution. A total of 35,597 individuals belonging to 84 taxa were identified, corresponding to Insecta, Mollusca, Crustacea, Annelida, Nematoda, Nemertea, Sipuncula and Collembola. Polychaeta showed the greatest species richness, while Tanaidacea were the most abundant. No gradient was found throughout the sampling sites with regard to the environmental variables, but marked differences were found in the temporal distribution. The temporal distribution of the benthic macrofauna was influenced by salinity and rainfall. Oligochaeta and Tanaidacea were abundant at all sampling sites. Acari were abundant in the inner portion of the estuary, while the number of Ostracoda was very high in the outer portion. The structure of the macrobenthic community differed in composition from the majority of the studies on estuaries, with the dominance of Tanaidacea and Oligochaeta. The higher abundance of Tanaidacea is related to environments rich in fine sediments with organic matter and the occurrence of this characteristics was determinant for the distribution of other taxa. The results indicate that the wet period favours the establishment of the benthic community, as evidenced by the increase in diversity and equitability.

Resumo em Inglês:

Abstract This study addressed the occurrence and distribution of benthic microalgae, with emphasis on toxic species, on different substrates (macroalgae, seagrass and sediments) along the outer, euhaline zone of the Estuarine Complex of Paranaguá Bay, southern Brazil, from July 2015 to May 2016. Canonical analysis of principal coordinates (CAP) was used to identify the potential environmental drivers of microphytobenthic assemblage structure. A total of 18 potentially toxic benthic microalgae species were reported, including 7 dinoflagellates, 9 cyanobacteria, one diatom and one euglenophyte. The abundance of all potentially toxic microalgae varied consistently along the investigated period. Dinoflagellates dominated the microalgae assemblage in July and September 2015. Mean densities on macrophytes ranged from 33.6 cells g-1 in May 2016 to 775.6 cells g-1 in September 2015, being positively correlated with dissolved nitrogen-nutrients, water transparency, salinity, and chlorophyll-a. Prorocentrum cf. lima was the most frequent and abundant dinoflagellate. Overall, the highest abundance of toxic species occurred in February 2016, when cyanobacterial mats dominated by Lyngbya cf. aestuarii were observed throughout the estuary associated with periods of heavier rainfall and higher turbidity (shallower Secchi depth). At that time, a selected microphytobenthic extract exhibited acute toxicity on nauplii of the brine shrimp Artemia salina in the laboratory.

Resumo em Inglês:

Abstract Bacteria with lipolytic activity are widespread in the marine environment. These organisms can be used as a source of lipases with activity in unusual conditions such as low temperatures and high salinities. These characteristics allow them to be applied to several industrial processes and products including wastewater treatment and detergent production. In this context the lipolytic activity of bacteria isolated from deep-sea sediments of the South Atlantic was evaluated. Among the collection studied, two strains, Halomonas sulfidaeris LAMA 838 and Marinobacter excellens LAMA 842, were selected for further analysis concerning their growth and lipolytic activity in different temperatures and culture media. Both strains were characterized as mesophiles: H. sulfidaeris LAMA 838 grew best at 30ºC, while M. excellens LAMA 842 showed a maximum growth rate between 20 and 25ºC. Maximum lipolytic activity for both microorganisms was observed above 45ºC, but only M. excellens LAMA 842 had lipolytic activity at low temperatures (5ºC) as well. Considering the culture media employed, H. sulfidaeris LAMA 838 grew better in marine broth without Tween 40, while M. excellens LAMA 842 grew best in marine broth supplemented with Tween 40. Both organisms had maximum lipolytic activity in rich or minimal media supplemented with Tween 40. These results demonstrate the potential of deep-sea bacteria as sources of lipases and indicate conditions that may be used in their cultivation and for the production of industrially relevant enzymes.

Resumo em Inglês:

Abstract Marine toxicity tests using sea urchin embryos and larvae are characterized by physicochemical induction for the release of gametes by adult organisms and by the production of excess gamic material after induction. Evaluating the effects of mortality that inducers cause on organisms, and the improvement in oocyte maintenance techniques for subsequent use, are actions of interest in the conservation of species and the sustainable use of this type of biological model. For this study, adults of the sea urchin species Lytechinus variegatus and Echinometra lucunter were obtained from the field for inductions and tests with their gametes in the laboratory. The species L. variegatus was used in maintenance experiments to assess health after induction (longline outdoor and indoor tanks) and mortality rates after induction by potassium chloride (KCl) and a mixture of potassium chloride with calcium chloride (CaCl2), and to evaluate bacterial growth as well as antibiograms of seawater resulting from induced spawning and in vitro fertilization. For the species E. lucunter, experiments with the same chemical inducers on mortality rates were carried out, as well as the conservation of oocytes in artificial seawater with antibiotics selected for their efficiency and toxicity for later use. Maintenance in the laboratory tanks, filled with seawater in a closed system, showed the lowest mortality rates in the group of non-induced organisms (control). The mixture of KCl and CaCl2 resulted in the lowest mortality rates of the adult organisms after spawning induction. The antibiotics Chloramphenicol and Gentamicin showed moderate efficiency in inhibiting bacterial growth, but with low toxicity, demonstrating the ability to maintain the integrity of sea urchin oocytes for up to 14 days under refrigeration.

Resumo em Inglês:

Abstract Ocean acidification (OA) poses a major threat to marine animals, especially marine shelled invertebrates such as molluscs. Although many organisms are capable of compensating for the effects of OA, this can impose physiological costs and impact performance (e.g. through increased metabolism and decreased growth). Sublethal injuries on shells may provoke changes in energy allocation. Under acidified conditions, organisms would spend less energy on reproduction and somatic growth to repair the damage. Therefore, we analysed the physiological responses of the intertidal gastropod Tritia reticulata during shell regeneration under OA conditions. We simulated a sub-lethal predation event (a notch in the outer lip of the shell) and individuals were exposed to control (pH 8.08) and low pH scenarios (pH 7.88 and 7.65). After two months exposure, all individuals showed shell repair, with a full repair rate observed in 75% of individuals. Contrary to expectations, shell repair following sub-lethal damage and OA had no apparent impact on physiological state in terms of energy reserves (as measured by whole-animal Carbon/Nitrogen) or growth potential (as measured by whole-animal RNA:Protein and RNA:DNA ratios). As an intertidal organism, T. reticulata could be resilient to future global environmental change because of compensatory mechanisms that are inherent in intertidal animals, and may represent a robust species with which to study future scenarios of OA in temperate coastal ecosystems. However, unrestricted food availability during experiment could have played a role in the results and therefore food limitation should be considered in future studies regarding shell repair and metabolism under the effects of OA.

Resumo em Inglês:

Abstract The aim of the present study was to quantify the suspended solid concentrations (CSSL) and suspended solid transport (TSSL) in the mixing zone of the Pará River Estuary. This estuary is located at the southeastern extreme of the estuarine complex of the Amazon River, and receives input from Tocantins and Pará rivers and other local tributaries, with a total discharge of approximately 104 m3 s-1. Two field campaigns were conducted to collect samples of Suspended Particulate Matter (SPM) and measure turbidity. Bottom and surface samples were collected hourly throughout a semidiurnal tidal cycle at two points in the estuary (Left Margin [LM]: -0.7287° -48.2408° and Right Margin [RM]: -0.6051° -48.4048°) in both the dry and rainy seasons. The TSSL was determined using a linear correlation between SPM and turbidity. The results indicate that both the RM and LM points were export routes of suspended solids to the adjacent ocean. However, both lateral and seasonal differences were observed in the PRE samples, with the RM point exporting more suspended solids to the adjacent ocean than the LM point. The TSSL was higher in near-bottom layers on the RM, and the lutocline was broader in comparison with the LM. The correlation between the CSSL at the bottom and in the water column was higher on the LM, and indicated that approximately 80% of the CSSL on this margin derives from resuspension. The sum of the evidence indicates that both points export suspended solids to the ocean.

Resumo em Inglês:

Abstract Identification keys are essential tools to guarantee higher precision during the taxonomic work. However, such keys are rare for foraminifera and often encompass a restrict group of species from a given geographic region. Thus, the taxonomic identification process usually occurs by visual comparison and by verifying the description of morphological attributes, which requires the previous knowledge of the species before identification. The use of an identification key seeks to help in this crucial step and contribute to the best taxonomic precision, which errors may propagate in the subsequent analyses that are supported by estimations on species richness and abundances. Moreover, it constitutes an extra tool to assist in the training of new researchers. This paper brings an identification key for agglutinant and monothalamous foraminifera from Brazilian mangroves, considering 50 genera and 91 species.

Resumo em Inglês:

Abstract Shrimps are the main fishery resource in marine waters off Sergipe (northeastern Brazil), where they are landed in three categories: ‘espigão’, ‘escolha’ and ‘pistola’. The objective of this study was to identify which species are landed in each category, relating to the perception of stakeholders, and to analyze their effect on the interpretation of historical catch statistics. Samples of 3kg were collected monthly for each category before landing in Aracaju (May/2015-May/2016) to identify the shrimp species caught. All specimens were identified, measured (carapace length - mm) and weighed (total weight - g), and had their sex determined. We interviewed attendees of two meetings promoted by the Programa de Monitoramento Participativo do Desembarque Pesqueiro in Aracaju and Pirambu, the two main ports where shrimp catches are landed in Sergipe, and asked for their perception of shrimp species included in each category. Finally, we used all shrimp catch data available for Sergipe in a national reconstructed database to improve the reconstruction based on the species composition estimated here for the main shrimp species. The analysis of each category indicated the presence of commercially important species (Xiphopenaeus kroyeri, Penaeus subtilis, Penaeus brasiliensis, and Penaeus schmitti), and also species of no local commercial interest: Exhippolysmata oplophoroides, Nematopalaemon schmitti, Rimapenaeus constrictus, and Sicyonia dorsalis. The category ‘espigão’ was dominated by X. kroyeri (94.2%) and ‘escolha’ by P. subtilis (95.3%). ‘pistola’ was mostly P. subtilis (78.3%), almost all of them females, followed by P. schmitti (12.3%). The perception of stakeholders was correct for ‘espigão’ and ‘escolha’, but not for ‘pistola’, as 38% of the respondents classified it as ‘camarão-branco’ (P. schmitti). The mean carapace length for all species together was: 18.90mm (‘espigão’), 22.34mm (‘escolha’), and 30.96mm (‘pistola’). Decreasing catches of X. kroyeri, P. subtilis and P. schmitti in the last years raise concern.

Resumo em Inglês:

Abstract Support vector machine (SVM) is shown to have better performance in catch per unit of effort (CPUE) standardization than other methods. The SVM performance highly relates to its parameters selection and has not been discussed in CPUE standardization. Analyzing the influence of parameter selection on SVM performance for CPUE standardization could improve model construction and performance, and thus provide useful information to stock assessment and management. We applied SVM to standardize longline catch per unit fishing effort of fishery data for bigeye tuna (Thunnus obesus) in the tropical fishing area of Atlantic Ocean and evaluated three parameters optimization methods: a Grid Search method, and two improved hybrid algorithms, namely SVMs in combination with the particle swarm optimization (PSO-SVM), and genetic algorithms (GA-SVM), in order to increase the strength of SVM. The mean absolute error (MAE), mean square error (MSE), three types of correlation coefficients and the normalized mean square error (NMSE) were computed to compare the algorithm performances. The PSO-SVM and GA-SVM algorithms had particularly high performances of indicative values in the training data and dataset, and the performances of PSO-SVM were marginally better than GA-SVM. The Grid search algorithm had best performances of indicative values in testing data. In general, PSO was appropriate to optimize the SVM parameters in CPUE standardization. The standardized CPUE was unstable and low from 2007 to 2011, increased during 2011-2013, then decreased from 2015 to 2017. The abundance index was lower compared with before 2000 and showed a decreasing trend in recent years.

Resumo em Inglês:

Abstract The aim of this study is to assess the morphological evolution of the Ararapira (Brazil) barrier-inlet system, at different time scales. Based on satellite imagery, elevation data, and in-situ observations, we quantify the morphological evolution of the region. Results show that the Ararapira inlet migrated continuously southwards, moving updrift, with erosion at its southern margin and intercalated erosion and accretion at the northern margin. At approximately 5.5 km north of the old inlet, the gradual narrowing of the sandy barrier due to channel meandering and coastal erosion resulted in its breaching, in August 2018. We document the initial stages of the new inlet, which after opening, presents intense erosion at its southern margin, resulting in the channel widening to ~1 km. After the barrier breaches, the system begins to adjust to a new equilibrium condition, with the widening of the new inlet being balanced by the gradual closure of the old inlet. These drastic environmental changes control the functioning of such systems, and our results provide important background information for their use and management.

Resumo em Inglês:

Abstract A highly aggressive necrotizing disease affecting the zooantharian Palythoa caribaeorum was studied on coastal reefs in northeastern Brazil during March and April of 2008. Approximately 87% of the colonies at each locality showed wounds ranging from 27 cm to 1200 cm long and from 12 to 320 cm wide. This disease initiates with the darkening of the polyps, followed by the appearance of a rapidly enlarging wound that decomposes colony tissues and eventually exposes the substrate. The exposed areas are subsequently colonized by macroalgae, Zoanthus sociatus, and other benthic organisms. The necrotized areas were dark-colored and expelled fetid odors. Although extremely aggressive, complete mortality of the colonies was not observed. Surviving fragments recomposed the colonies within 6 to 9 months. Recurrences of the disease were in the summer of 2008 and from February/2013 to March/2014. During the study period, we found various colonies having black-spots (early stage of necrotizing disease), suggesting stress conditions. Zooxanthellae densities in those black-spots were always lower than in apparently healthy colonies, with reductions of up to 74%. More than one environmental variable seems to influence the zooxanthellae densities significantly, but there is no evidence of any association with abnormally high water temperature, as thermal variations in the study area were within their normal range. Histological analysis showed losses of tissue organization in colonies with black-spots and necrotizing components with hypertrophy and cell apoptosis of the gastrodermal cells; apoptosis of zooxanthellae and damage in completes mesenteries. All these features showed an inflammatory response to necrosis disease.

Resumo em Inglês:

Abstract The main purpose of the present work was to determine chitin from experimental size-fractioned incubations of the copepod Acartia tonsa, considered one of the primary sources of chitin in the Bahía Blanca Estuary. Sampling was performed during the austral warm season at one station in 2014 and 2015. Field-collected females (200 individuals) and males (100 individuals) were incubated in 8 L containers in the laboratory simulating in situ environmental conditions of temperature and salinity for 72 hours. Chitin content was measured in different size fractions (20-60, 60-135 and ≥135 µm). Particulate organic matter and dry weight were also determined in the different size fractions. Highly agglutinated debris, pellets, and natural food (diatoms and tintinnids) were observed in the 20-60 µm size fraction, with a maximum of 0.68±0.21mg L-1 chitin, and the highest contribution of chitin to POC (34.62±18.50 %). Eggs, nauplii and natural food (diatoms and tintinnids) were observed in the 60-135 µm size fraction, with a maximum of 0.20±0.12 mg L-1 chitin and a contribution to POC of 9.80±5.00 %. Acartia adults and their exuviae were observed in the ≥135 µm size fraction, with a maximum concentration of chitin of 0.67±0.40, and a maximum contribution of chitin to POC TS of 30.47±27.23 %. Differences were detected between the different fractions in chitin, POC and DW, indicating that the 20-60 and ≥135 µm size fractions were both an important contribution of chitin in the experiment. Our results suggest that pellets, carcasses and exuviae along with natural food and organic aggregates were the main source of chitin in this system.

Resumo em Inglês:

Abstract The irregular hydrological regime in Patos Lagoon estuary has been suggested as having a distinctive influence on sulfur speciation in sediments. We performed an investigation for different prolonged hydrological conditions focusing on the distribution of sulfides (acid volatile sulfide (AVS), chromium reducible sulfide (CRS), and Free-S2-) in sediment cores from salt marsh and non-vegetated shallow zone. Significant differences in sulfides content and distribution between the different hydrological periods were found. The predominance of more reducing conditions was observed during the freshwater period. It reflects a higher total reducible inorganic sulfur (TRIS) content in this period, with a great accumulation of AVS in sediments (> 100 mg kg-1). In the maximum salinity period, more oxidizing conditions prevailed, which significantly decreased the concentrations of metastable sulfides. The intense bioirrigation process exerts control over sulfide formation and distribution, which is as important as that exerted by the variations of the hydrological regime.

Resumo em Inglês:

Abstract The Neogene benthic foraminiferal ecostratigraphy of offshore Pelotas Basin has not yet been researched. The benthic foraminifera were examined in twenty-nine ditch cuttings samples from Well 1-SCS-3B, present water depth 200 m. These samples ranged from the Lower Miocene Catapsydrax dissimilis planktonic foraminiferal Zone to the Pliocene Globigerinoides trilobus fistulosus Zone. Only ditch cuttings were available, which allowed us to present just broad paleoenvironmental trends within the studied section. Benthic foraminifera indicate deposition mostly between outer neritic to upper bathyal paleodepths. A peak in uvigerinid relative abundance marks a possible flooding surface or condensed section with a high nutrient flux, low diversity (marked by the Shannon Function H), and sluggish circulation within the Globorotalia mayeri Zone. This peak is bracketed by high abundances of Cibicidoides, which indicate stronger current action than within the condensed section. Biostratigraphic hiatuses within these Cibicidoides-rich intervals are concluded not to indicate subaerial exposure, but to reflect current action sufficiently strong to induce either non-deposition or seafloor scouring. A second possible flooding surface occurs at the top of the section, indicated by a decline in Cibicidoides associated with upticks in Sphaeroidina and Bolivina and a dip in H. The top of this younger maximum flood was not encountered, probably occurring above the studied section. That the timing of these floods differs from those recorded elsewhere in the Pelotas Basin implies that they were tectonically induced, perhaps as distal effects associated with the interaction between the South American and Nazca tectonic plates. Future studies with better quality core samples will add detail to this picture; such studies can incorporate eustatic sea-level changes into the model presented.

Resumo em Inglês:

Abstract Catches of pelagic fish associated to anchored Fish Aggregating Devices have been responsible for increases in income, fish consumption, and even cultural identity of artisanal fishing communities in many developing countries worldwide. Nonetheless, in Brazil, aFAD fishing is still poorly developed and studied. In this experiment, FADs were anchored offshore the city of Recife (Northeastern Brazil) to investigate the potential of moored buoys in the aggregation of commercially important pelagic species near the coast, as an alternative fishing site for artisanal fishers. The behavior of acoustically tagged fish was investigated to assess whether they were attracted to the FADs and how long they remained associated to them. The results indicated that, although economically important species were found near the FADs, they did not remain associated for long periods. From the four species tagged, Acanthocybium solandri, Coryphaena hippurus, Thunnus atlanticus, and Caranx crysos, only the two latter were detected at the FADs. Both species presented a preference for a specific FAD, with stronger site fidelity being recorded for C. crysos. This species presented Total Resident Times (TRTs) of more than a month and continuous residence times of more than 14 consecutive days. T. atlanticus, on the other hand, remained around the buoys for short time intervals, with a maximum TRT of only two days. Short diurnal excursions far from the FADs and few longer excursions during nighttime were recorded for C. crysos. These results do not support the possible use of moored FADs near the coast of Recife as an alternative fishing site for artisanal fisheries. It is possible that the geomorphological characteristics of the experimental area did not favor the aggregative behavior of large pelagic fish species, such as tunas, around FADs.

Resumo em Inglês:

Abstract This paper describes wave prediction results for Patos Lagoon's northern sector through numerical modeling using Delft3D software. ERA-Interim satellite reanalysis data of wind intensity and direction were used as inputs to force the hydrodynamic model. For SWAN calibration and validation in the study region, wave parameters were used. These parameters were acquired in situ by a directional waverider buoy. Statistical data showed the good performance of the model, albeit with a tendency to overestimate significant wave height and underestimate peak period and propagation direction. Once validated, wave parameters for five points at different depths were obtained during the four seasons of the year between 2017 and 2018. In general, it was observed that the largest ripples come from the S and SSW directions and occurred during spring at the deepest point under wind conditions exceeding 10 m s-1. Ripples up to 0.30 m account for 77.9 % at the shallowest point and 65.7 % at the deepest point. Thus, the study area was classified as low energy and characterized by small, high-frequency, short-period ripples strongly influenced and determined by the local depth because larger ripples are always observed in the deepest locations, giving the lagoon a characteristic of depth-limited ripples. The results obtained here have the potential to contribute to territorial management of the region, with emphasis on the Integral Protection Conservation Unit located in the study area (Itapuã State Park) and on the development and safety of the important, heavily used navigation route that connects Rio Grande Port to the state capital, Porto Alegre.

Resumo em Inglês:

Abstract Terrestrial runoff is a source of sediments and nutrients to coral reefs. Due to runoff, Brazilian reefs are typically turbid, and have coral species that are naturally turbidity-resistant. This study investigated how terrestrial input influences population and physiology for the coral Favia gravida on two reefs with differences in river mouth proximity in eastern Brazil. The population structure and physiological traits of F. gravida colonies were assessed on both reefs, then some colonies selected for a subsequent transplantation experiment. The reef less impacted by terrestrial influence showed higher population density and lower recruitment. At this site, the coral colonies displayed higher calcification and larger larvae. The reproductive effort between coral populations at the two sites showed no significant difference. The transplantation experiment confirmed the high physiological plasticity of F. gravida colonies at the more turbid reef site. Despite being regarded as a more challenging environment, where F. gravida has a lower population density, the reef closer to the river mouth appears to secure more nutrients, which may heterotrophically compensate its coral colonies.

Resumo em Inglês:

Abstract With the increased density of available observation data, data assimilation has become an increasingly important tool in marine research. However, the success of the ensemble Kalman filter is highly dependent on the size of the ensemble. A small ensemble used in data assimilation could cause filter divergence, undersampling and spurious correlations. The primary method to alleviate these problems is localization. It can eliminate some spurious correlations and increase the rank of the forecast error covariance matrix. The ensemble transform Kalman filter has been widely used in various studies as a deterministic filter. Unfortunately, the covariance localization cannot be directly applied to ensemble transform Kalman filter. The new covariance localization needs to be presented to adapt the ensemble transform Kalman filter. Based on the method of expanded ensemble and eigenvalue decomposition, this study describes a variation of covariance localization that takes advantage of an unbiased covariance matrix from the expanded ensemble. Experiments described herein show that the new method outperforms the localization methods proposed by others when used in the ensemble transform Kalman filter. The new method yields an analysis estimate that is closer to the true state under different experimental conditions.

Resumo em Inglês:

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