Environmental assessment of dredged sediment in the major Latin American seaport (Santos, São Paulo-Brazil): an integrated approach

A decade of toxicity research on sea urchins: A review

Sea urchins have been used extensively in toxicity studies worldwide. In this review, toxicity studies that used sea urchins as the organism of choice during the last decade (from 2014 to 2023) were assessed. The selected articles were analysed for the following main points: (i) the world regions where sea urchins are predominantly utilized in toxicological studies, (ii) the sea urchin species most frequently employed, (iii) the most frequently used toxicological assays, and (iv) the chemical under examination. The results indicate that the scientists in Europe most often decide to work with this organism. Specifically, sea urchins were sampled from the Tyrrhenian Sea and the Atlantic coast of Spain and Portugal for the toxicity studies. The most frequently selected species of sea urchin is Paracentrotus lividus, followed by Arbacia lixula and Strongylocentrotus purpuratus. Furthermore, the toxicity experimental method that is most often applied is the embryotoxicity that includes a version of the sea urchin embryo-larval development test endpoints. Currently metals are the most frequently researched pollutant of this species as target organism, followed by environmental samples (e.g. sediment or wastewaters), plastics and nanoparticles (metal and metal oxide nanoparticles, silicate nanoparticles, polystyrene nanoparticles and carbon nanotubes). At the end, the obtained results were discussed and recommendations for further work with sea urchins in toxicological studies were proposed.

Metal concentration in ghost shrimp and contamination levels of sandy beaches contrasted with anthropogenic impacts in Southeast Brazil

This study evaluates the contrast in the concentration of seven potentially toxic elements (As, Cd, Cr, Cu, Hg, Mn, and Pb) in tissues (G, gonads; H, hepatopancreas; and M, muscle) of the ghost shrimp Callichirus corruptus, as a response to sediment contamination in two sandy beaches in Southern Brazil with different anthropogenic status (JUR, Juréia; and STS, Santos). The biotic and abiotic samples were collected with a suction pump and subjected to metal quantification by atomic absorption spectrophotometry technique. In JUR, the sediment had Cr, Cu, and Mn concentrations two times lower when compared to STS (t ≤ 7.80; p ≤ 0.01), while STS had Hg concentrations between the Interim Sediment Quality Guideline (ISQG) and probable effect level (PEL) parameters. Three metals (Cd, Cr, and Cu) presented concentrations above the maximum tolerated limit indicated by the Brazilian Health Regulatory Agency (Anvisa), with prawn bioaccumulation up to eight times greater in STS than JUR (t ≥ 4.42; p ≤ 0.03). Therefore, this study confirms higher metal concentrations (μg/g) in the biotic (Cd = 7.86 Cr = 11.95 and Mn = 19.38) and abiotic (Cd = 0.45, Cr = 3.13, Cu = 0.59, Hg = 0.49 and Mn = 45.61) compartments of Santos, which has a high human population density and a significant industrial and port complex, in contrast to Juréia, which is located in a highly conservation ecological station. Furthermore, the research presents novel information on trace elements in the sandy sediments of the studied sites. Additionally, it provides unprecedented evidence on metal concentration for C. corruptus, which can be used in monitoring programs for sandy beaches due to its metal bioaccumulation potential.

Toxicity of Per- and polyfluoroalkyl substances in elutriates prepared with estuarine and freshwater sediments

PFAS has a ubiquitous environmental occurrence, posing challenges to sediment management. To address data gaps concerning release of PFAS from sediment to the water column during dredged material aquatic placement or other sediment resuspension activity, we generated elutriates from PFAS-contaminated sediments. Sediments were obtained from both freshwater and estuarine environments, with a field-collected sediment representative of contaminated areas and a spiked sediment with concentrations exceeding levels frequently measured at contaminated sites. We then conducted acute toxicity tests of the elutriates with species standardly used in dredging evaluations: the sheepshead minnow (Cyprinodon variegatus), the fathead minnow (Pimephales promelas), the water flea (Ceriodaphnia dubia), and the Mysid shrimp (Americamysis bahia). PFAS partitioning to sediment and organic matter was observed to increase with carbon chain length. PFAS-induced mortality was not observed in any of the four test species, as measured concentrations of PFAS were below levels known to cause negative effects in these organisms. Though PFAS concentrations in the spiked sediment elutriates exceeded concentrations known to cause effects in the most sensitive aquatic species, PFAS levels in the more environmentally relevant field-collected sediment elutriates did not. Consequently, PFAS released from the sediment to the water column is not expected to cause toxicity to pelagic biota during aquatic placement of dredged material.

A comprehensive review of polycyclic aromatic hydrocarbons in Brazilian coastal environments

This study provides an overview of the evaluation of polycyclic aromatic hydrocarbons (PAHs) in the coastal regions of Santos Basin, located in Brazil's Southeast region, the country's most industrialized area. The analysis is based on data compiled from various studies in this area since 2000. A comprehensive literature review was conducted using the SCOPUS database, encompassing peer-reviewed scientific journals from publishers such as Elsevier, Springer, Nature, Wiley, Taylor & Francis, Google Scholar, and ResearchGate. Most of these studies have focused on the sediment compartment due to its role as the primary repository for organic matter and, consequently, PAHs in the marine environment. However, the bioavailability of organic contaminants in sediment is generally lower compared to water and suspended particulate matter, which has received less attention in the context of Santos Basin. The literature search also includes studies evaluating PAH concentrations in organisms to investigate the bioaccumulation rates of these compounds. Data presented in this review primarily originates from coastal and estuarine areas within Santos Basin, with occasional extensions to the continental shelf. The majority of publications are centered on studies conducted in the southeastern Brazilian states of São Paulo and Rio de Janeiro, where the highest levels of PAH contamination across all environmental compartments are typically observed. Santa Catarina, on the other hand, is the coastal region with fewer studies. The regions where most of the studies involving PAHs in the Santos Basin are concentrated in areas where public university research centers are located, a pattern that repeats throughout the Brazilian coast. In areas far from universities, little is known about the environmental status of PAHs.

Levels, spatial distributions, and provision of petroleum hydrocarbons and phthalates in sediments from Obhur lagoon, Red Sea coast of Saudi Arabia

The levels, spatial distribution, and sources of petroleum hydrocarbons and phthalates were assessed in surface sediment samples from the urban lagoon of Obhur near Jeddah, the largest city on the Red Sea coast of Saudi Arabia. The lagoon was divided into the inner zone, middle zone, and outer zone based on its geomorphological features and developmental activities. n-Alkanes, hopane and sterane biomarkers, and unresolved complex mixture were the major petroleum hydrocarbon compounds of the total extractable organic matter. Phthalates were also measured in the sediment samples. In the three zones, n-alkanes ranged from 89.3 ± 88.5 to 103.2 ± 114.9 ng/g, whereas the hopane and sterane biomarkers varied from 69.4 ± 75.3 to 77.7 ± 69.9 ng/g and 72.5 ± 77.9-89.5 ± 82.2 ng/g, respectively. The UCM concentrations ranged from 821 ± 1119 to 1297 ± 1684 ng/g and phthalates from 37.4 ± 34.5 65 ± 68 ng/g. The primary origins of these anthropogenic hydrocarbons in the lagoon sediments were petroleum products (boat engine discharges, boat washing, lubricants, and wastewater flows) and plasticizers (plastic waste and litter). The proportions of anthropogenic hydrocarbons derived from petroleum products in the sediment's TEOM ranged from 43 ± 33 to 62 ± 15%, while the percentages for plasticizers varied from 2.9 ± 1.2 to 4.0 ± 1.6%. The presence and inputs of these contaminants from petroleum and plastic wastes in the lagoon's sediments will eventually have an impact on its habitats, including the benthic nursery and spawning areas.

Navigating the PAH maze: Bioaccumulation, risks, and review of the quality guidelines in marine ecosystems with a spotlight on the Brazilian coastline

This review delves into the intricate world of Polycyclic Aromatic Hydrocarbons (PAHs) and their bioaccumulation in marine organisms. It explores how physicochemical attributes of individual compounds, along with metabolic oxidation and elimination processes, influence this bioaccumulation. The review further investigates the risks and toxicity associated with PAHs in marine organisms. Subsequently, sediment and water quality guidelines used to assess the potential for adverse effects from PAH exposure are discussed exposing significant differences in the methodological approaches used to establish the guidelines, which can lead to discrepancies in the values used to compare PAH concentrations and limitations to their use. Emphasis is placed on the criteria employed in establishing these guidelines, rooted in adverse effects data linked to PAHs, and efforts to establish local quality guidelines for a tropical area are described. This exploration serves to enhance our understanding of the complex interplay between PAHs and marine ecosystems, informing more effective environmental management strategies.

Preparation of water storage ceramsite via dredged silt and biomass waste: Pore formation, water purification and application

Natural water pollution and eutrophication are environmental problems that urgently need to be solved. Porous ceramsite could be applied for both water storage and water purification. This research used biomass and dredged silt to prepare water storage ceramsite (WSC), and investigated the adsorption and removal effects of WSC on phosphorus (P), nitrogen ((NH⁴⁺)N) and chemical oxygen demand (COD). The results showed that the biomass was mostly burned and partially carbonized during the high-temperature sintering process to form a rich pore structure inside the material. The rich pore structure effectively improved the water absorption to 105.58 %. The abundant specific surface area could provide many attachment sites, which is conducive to the adsorption of target ions by WSC. Further testing showed that WSC could adsorb ions with different charges in different pH solutions. Therefore, this study provides a sustainable solution for the co-utilization of biomass waste and dredged silt, and the application of WSC could reduce the damage caused by extreme rainfall and water pollution.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Historical mercury contamination in a major Latin American industrial and port complex: The case of the Santos estuary, Southeastern Brazil

The present study determined total mercury (Hg) in four ²¹⁰Pb dated sediment cores to assess the historical anthropogenic Hg accumulation in the Santos estuary, Southeastern Brazil. Background levels were identified using the deepest sections of the cores, corresponding to pre-industrial ages. Mercury distribution in the sediment cores (0.02-2.64 mg kg^-1) presented a large spatial and temporal variation. Contamination is highest in the upper estuary and indicates that the industrial hub, especially a chlor-alkali plant is the primary source of Hg. A contaminant trap effect is observed in this area associated with high fine sediment accumulation and Hg fluxes. The contamination pattern indicates that the regions not affected by direct inputs are influenced by reworking, resuspension, and transport of contaminated sediments by tidal flows. The Hg enrichment in the upper layers of the sediment cores demonstrates that the environmental actions fulfilled in the 1980s were insufficient to control Hg pollution in the Santos estuary.

A 140-year record of environmental changes in São Sebastião, Brazil

Over the past two centuries, coastal and estuarine areas have experienced environmental stress due to rapid population growth, leading to higher demand, overexploitation, habitat transformation, and pollution, which have severe consequences on the overall ecosystem and human health. This work aims to understand historical perspectives of such environmental stress in a coastal area of São Sebastião city in the São Paulo State of Brazil, which has witnessed rapid changes in land use over the past 60-70 years. We collected eleven surface sediments and one 64 cm long core from the shallow water depth sector of the São Sebastião Channel (SSC), adjacent to the Araçá Bay region. Sediments were dominantly composed of terrestrial siliciclastic material carrying signatures of both local inputs (i.e., weathered granitic and gneissic rocks of Serra do Mar Mountain ranges) and Plata Plume sediments brought by Brazilian coastal currents. Low sediment accumulation (avg. = 0.10 cm yr^-1) between 1880 and 1947 showed a stable environment followed by an abrupt increase in sedimentation (avg. = 0.84 cm yr^-1) from 1947 to 2017. This approximate eight-fold increase in sedimentation after 1947 marked significant anthropogenic changes in the region, which is coincidental with major changes in land use through the construction of the port of São Sebastião (1930s) and BR-101 Highway (1980s). While recent surface sediments showed no pollution of heavy metals, anthropogenic Zn enrichment was found between 1880 and 2000. Zn enrichment was from the combined sources, e.g., agriculture activities, domestic sewage, and possibly Zn coated ship paints. Our study also indicates that planned future expansion of São Sebastião port may further increase the sedimentation rate in SSC and impact the ecosystem of Araçá Bay and SSC.

An overview and assessment of the existing technological options for management and resource recovery from beach wrack and dredged sediments: An environmental and economic perspective

The present work discusses the problems and management options of beach wrack and dredged sediments. Beach wrack and dredged sediments near the shores have affected the coastal ecosystem, badly. The piles of beach wrack residues might be a significant emitter of greenhouse gases (GHGs) and dredged sediment is a substantial source of heavy metals and other pollutants. The recovery of valuable resources such as metals and nutrients from these so-called "wastes" is a sustainable strategy to enhance the resilience of the coastal ecosystem and management. The beach wrack meadows can be a potential source for green energy production. Even the demand for biodegradable polymers can be supplied by utilizing the waste beach wracks. The residues of beach wrack species like Posidonia oceanica, Zostera marina, Ulva spc. and Enhalus acorodies can be very beneficial species in terms of economic growth. Red algae have been the most favored and efficient candidate for methane yield. In case of dredged sediment, dewatering of sediment is an essential step for successful resource extraction. Although, extraction methods are almost similar to that applied for soil treatment, which includes pretreatment, physical partitioning, washing, thermal treatment, biological extraction, and immobilization. The fractionation study can be a beneficial tool for determining the metal species present in the sediment. Immobilization techniques are successful but continuous monitoring is required. The vitrification technique is highly effective but very expensive. Thermal treatment is useful for volatile metals such as mercury (Hg), but costs are high. Biological extractions are comparatively cheap but time-consuming. Henceforth, very few extraction methods are available for sediment and required further advancement in this field.

Dredging impacts on the toxicity and development of sediment quality values in a semi-arid region (Ceará state, NE Brazil)

Sediment dredging impacts coastal environments by promoting the resuspension of fine particles and remobilization of contaminants that may trigger toxic effects. In this study, we evaluated the sediment quality in harbor areas of Mucuripe bay, a semi-arid ecosystem located in Ceará state (Brazil), which is subject to dredging activities. A sampling survey was conducted right after dredging operations and data compared to another survey performed prior dredging. Sediments were analyzed for fine particles, organic carbon, nutrients, metals, hydrocarbons, and tributyltin (TBT). Toxicity of whole-sediment and liquid phase exposures were also determined. The concentrations of Cd, Cr, Cu, and Zn decreased after dredging, which was confirmed by the geoaccumulation index. Levels of TBT dropped while phosphorus, aliphatic and polycyclic aromatic hydrocarbons increased. Toxic effects persisted, indicating a post-dredging recontamination combined with other sources such as urban runoff, wastewater discharges, harbor activities, and antifouling particles. Data from Mucuripe and Pecém harbors were compiled and site-specific sediment quality values (SQVs) were developed by using multivariate methods. The threshold values proposed by our study were lower and more effective to predict toxicity compared to international guidelines, indicating levels of contamination for this tropical region in which toxic effects may occur. Considering the large geographic area with different sediment characteristics of the Brazilian coast, this study represents a significant contribution to sediment toxicity assessment of dredging activities in semi-arid environments.

Marine protected areas in Latin America and Caribbean threatened by polycyclic aromatic hydrocarbons

The present study is a literature-based analysis investigating occurrence and the possible consequences of polycyclic aromatic hydrocarbons (PAH) in marine protected areas (MPAs) of Latin America and Caribbean. The approach using overlapping of georeferenced MPA polygons with data compiled from peer-reviewed literature, published during the last 15 years, showed 341 records of PAH in 9 countries. PAH was reported to occur within the boundaries of 36 MPAs located in Argentina, Brazil, Colombia, Mexico, Nicaragua and Uruguay. According to quality guidelines, low to moderate impacts are expected in MPAs categorized in different management classes. Considering sediment samples, 13% of the records presented concentrations enough to cause occasional toxicity. Such level of risk was also seen in Ramsar sites and in Amazonian MPAs. In addition, based on concentrations reported in biota, occasional deleterious effects on organisms from Biosphere Reserves might occur. Diagnostic ratios pointed out petrogenic and pyrolytic processes as PAH predominant sources, and were mainly attributed to the proximity to ports, industries and urban areas. MPAs located in the vicinity of impact-generating areas may be under threat and require government attention and action, mainly through implementation of contamination monitoring programs.

Chemical speciation of metals from marine sediments: Assessment of potential pollution risk while dredging, a case study in southern Sweden

Contamination associated with metals is a critical concern related to their toxicity, persistence, and bio-accumulation. Trace elements are partitioned into several chemical forms, which some are more labile during fluctuations in the environment. Studying the distribution of metals between the different chemical fractions contributes to assess their bioavailability and to identify their potential risk of contamination to surrounding environments. This study concerns the speciation of metals (Pb, Cr, Ni, Zn and Fe) from sediments coming out from Malmfjärden bay, Sweden. The aim was to assess the potential risk of metal pollution during present and future dredging as well as while using dredged sediments in beneficial uses. The Tessier speciation procedure was chosen, and the results showed that low concentrations of metals were associated with the exchangeable fraction. In contrast, the major concentrations were linked to the residual part. The risk indexes (contamination factor and risk assessment code) showed that, during dredging activities, there is a low concern of pollution for Cr, Ni and Fe and a medium risk for Pb and Zn. Additionally, in all elements, the sum of non-residual concentrations was below the Swedish limits for using dredged sediments in sensitive lands. The findings suggested that the investigated metals in Malmfjärden sediments are related to low risks of spreading during using in beneficial uses.

Effect of Different Rates of Nitrogen Fertilization on Crop Yield, Soil Properties and Leaf Physiological Attributes in Banana Under Subtropical Regions of China

Excessive nitrogen (N) application is widespread in Southern China. The effects of N fertilization on soil properties and crop physiology are poorly understood in tropical red loam soil. We conducted a field experiment to evaluate the effect of nitrogen fertilization rates on physiological attributes (chlorophyll, plant metabolic enzymes, soluble matters) on banana leaves, soil properties (soil enzymes, soil organic matter (SOM), soil available nutrients) as well as banana crop yield in a subtropical region of southern China. The N rates tested were 0 (N₀), 145 (N₁₄₅), 248 (N₂₄₈), 352 (N₃₅₂), 414 (N_FT), and 455 (N₄₅₅) g N per plant. The correlations among soil factors, leaf physiological factors and crop yield were evaluated. The results indiated that the high rates of N fertilization (N_FT and N₄₅₅) significantly decreased soil available potassium (K) content, available phosphorus (P) content, glutamine synthetase (GS) activity, and soluble protein and sugar contents compared with lower N rates. The N₃₅₂ treatment had the highest crop yields compared with higher N rates treatments, followed by the N₄₅₅ treatment. However, there were no significant differences in crop yields among N fertilization treatments. Factor analysis showed that the N₃₅₂ treatment had the highest integrated score for soil and leaf physiological factors among all treatments. Moreover, the N₃₅₂ treatment was the most effective in improving carbon and nitrogen metabolism in banana. Crop yield was significantly and positively linearly correlated with the integrated score (r = 0.823, p < 0.05). Path analysis revealed that invertase, SOM and sucrose synthase (SS) had a strong positive effect on banana yield. Canonical correspondence analysis (CCA) suggested that available K, invertase, acid phosphatase and available P were the most important factors impacting leaf physiological attributes. Cluster analysis demonstrated distinct differences in N application treatment related to variations in soil and leaf factors. This study suggested that excessive N fertilization had a negative effect on soil fertility, crop physiology and yield. The lower N rates were more effective in improving crop yield than higher rates of N fertilization. The N rate of 352 g N per plant (N₃₅₂) was recommended to reduce excess N input while maintaining the higher yield for local farmers' banana planting.

Environmental consequences of dredged-material disposal in a recurrent marine dumping area near to Guadalquivir estuary, Spain

In this study we assessed the effects of the recurrent disposal of dredged material from the Guadalquivir estuary (south-western Spain) in a marine disposal area. We analysed shifts in sediment characteristics as well as bioaccumulation and biomagnification of heavy metals through the benthic food web. Results showed that the significant increase in concentration of some heavy metals observed in the marine disposal area after the latest disposal event could be attributed to the deposition of river-dredged sediments. This increase could also explain the decreased amphipod survival in the ecotoxicology analysis. Heavy metal concentrations in organisms indicated some bioaccumulation in deposit feeders and predators but with no clear patterns nor biomagnification through the food web. Hence, combining studies that monitor shifts in sediment characteristics and their possible consequences for the food web seems to be an interesting approach that should be assessed further in this type of studies.

Assessing the Complexity of Social-Ecological Systems: Taking Stock of the Cross-Scale Dependence

Human demands and activities introduce cross-scale pressures in different systems and scales, affecting the provision of ecosystem services and causing an unbalanced effect on human well-being within the territory. The existing institutions are frequently considered panaceas since they do not take into account the different spatial and jurisdictional scales of the social-ecological systems (SES). This paper aims to broaden the existing DPSIR (Drivers–Pressures–State–Impact–Response) assessment frameworks to strengthen the ecosystem approach and promote an integrated cross-scale perspective. The concept of the Cross-scale Ecosystem-Based Assessment (DIET) was developed and applied to a case study on the demand of seafood provisions. The assessment has indicated that the activities related to the specified demand occur at different scales and generate cumulative impacts and pressures on other scales, especially in the coastal zone. The existing responses to address this issue are highly fragmented, both spatially and among sectors. DIET was applied here to the land–sea interface to illustrate how coastal zone governance and management can be improved and how the impact of certain drivers or activities in the SES can be reduced. DIET may help to reduce the governance morbidity and prevent panaceas by fostering the integration of institutions in pursuing flexible, adaptive and fit-for-purpose policies to address complex issues so as to secure social-ecological justice and well-being for all humans.

Soft-bottom community responses in a marine area influenced by recurrent dumping activities and freshwater discharges

The results of a 3 years monitoring program to assess the effects associated with recurrent dredged spoil disposal activity in a naturally stressed subtidal coastal area subjected to estuarine inputs are described. Changes observed through time in environmental and anthropogenic variables have been analyzed using cumulated sums and compared to macrobenthic community structure. Results revealed a scarce impact of the recurrent dumping activities, with faunal assemblages derived from the main "Tellina-venus community". The magnitude of estuarine influence appeared indeed greater on the soft-bottom community than the putative changes due to anthropogenic activities. Through a combination of high energetic conditions, structural changes were observed and ascribed to a flushing action of the highly channeled estuary. Finally, an exceptional flood was recorded over the monitoring period, resulting in a short-term spatial homogenization of the benthic community with an abundance burst of A. alba. Origins of this main new species are discussed.

Metal pollution in surface sediments from Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil): Toxic effects on marine organisms

The Rodrigo de Freitas Lagoon (RFL - Rio de Janeiro, RJ, Brazil) is a highly polluted and eutrophic lacustrine system, which has been often used for the practice of aquatic sports, including during the 2016 Summer Olympic Games. This study proposes the evaluation of metal concentrations in surface sediments from the RFL before and after urban interventions performed for the 2016 Olympics, as well as their toxicity to the benthic amphipod Tiburonella viscana and embryos of the sea-urchin Echinometra lucunter. Metal concentrations determined in 2017 were significantly higher than those obtained in 2015 (especially Cu, Cd and Ni), suggesting that the interventions performed to fulfill the requirements of the Olympics increased metal contents in sediments. The sediments from the northern sector of the RFL were muddier, more organically enriched, exhibited higher metal concentrations and were more toxic to T. viscana when compared to the sediments collected in the southern sector. This fact is particularly important since the practice of sports, including during the 2016 Olympics, has been preferably performed in the northern sector. Metal distribution was strongly correlated with organic matter and mud contents. The toxicity to E. lucunter embryos was high for both northern and southern sediments; most of the samples led to 100% lack or abnormal embryonic development. The integration of physical, chemical and ecotoxicological data indicates that the mortality to T. viscana was correlated with metal contents, whereas the toxicity to E. lucunter was apparently related to the release of ammonia from the sediment to water column. Finally, high metal concentrations and the toxicity to aquatic organisms evidence the ecological risks to the biota from RFL.

Can shell alterations in limpets be used as alternative biomarkers of coastal contamination?

The present study evaluated the association among traditional biochemical biomarkers with biometric, morphometric, and elemental composition of Lottia subrugosa (patelliform gastropod) shells from three multi-impacted coastal areas in Brazil. The study was carried out in Todos os Santos Bay (TSB), Santos/São Vicente Estuarine System (SESS) and Paranaguá Estuarine Complex (CEP), using three sampling sites to seek contamination gradients in each area. Results showed that all biomarkers evaluated responded to environmental contamination, regardless the presence (SESS and CEP) or absence (TSB) of a gradient of contamination. The responses found using biometric and morphometric parameters were consistent with the traditional biomarkers of exposure and effects (lipid peroxidation and DNA damage). Indeed, changes in elemental composition of L. subrugosa shells suggest that exposure to contaminated environments is probably responsible for the alterations detected. Despite the simplicity and lower cost of biometric and morphometric analyzes, these parameters are influenced by natural environmental conditions from which biases may arise. Therefore, these tools should be evaluated through experimental studies before it can be used in future assessments. However, the findings from the present study were observed in three aquatic systems distributed over a wide range of latitudes, which indicates that gastropod shells reflect effects resulting from environmental contamination.

Hexadecane biodegradation of high efficiency by bacterial isolates from Santos Basin sediments

The aim of the study was the investigation of bacterial diversity from sediments collected at Santos Estuarine System, regarding to their abilities for hexadecane biotransformation. Hexadecane is a medium-chain linear alkane, considered as a model molecule for hydrocarbon biodegradation studies. It is a component from aliphatic fraction of crude petroleum, commonly related to environmental contamination by diesel oil. Santos Basin is an area with historical petroleum contamination. In the present work, sediment samples from this area were inoculated in artificial seawater (ASW), containing hexadecane as carbon source. Six bacterial isolates were selected as resistant to hexadecane. Chromatographic results showed biodegradation indexes above 97%. After 48 h of culture, five of them could degrade >80% of the initial hexadecane added. These isolates were characterized by 16S rDNA gene sequencing analysis. The following species were found: Bacillus amyloliquefaciens, Staphylococcus epidermidis, Micrococcus luteus, Nitratireductor aquimarinus, and Bacillus pumilus.

Impact of dredged-material disposal on soft-bottom communities in a recurrent marine dumping area near to Guadalquivir estuary, Spain

This study assesses the effects of dredged material disposal in a recurrent marine dump near the Guadalquivir Estuary (south-western Spain). We compared the changes observed with two reference areas combining a classical ecological approach with new stable isotope techniques to analyse trophic structure. We detected permanent changes in the macrofaunal community structure as well as in the diversity and biotic indices applied, which showed higher values in the disposal area. The community in the marine dump had lost the natural temporal variations observed in the reference areas. These effects could be due to the last disposal event carried out in the summer of 2015 or to the recurrent disposals since 2010. Despite the structural changes shown by the benthic community, these impacts were not reflected in the food web structure of the marine dump. Our results confirm the high variability of disposal disturbances. Hence, we recommend performing studies in every disposal event, merging different functional and structural approaches.

Critical evaluation of different methods to calculate the Geoaccumulation Index for environmental studies: A new approach for Baixada Santista - Southeastern Brazil

Although the Igeo is widely used in heavy metal contamination studies, its application differs in each study in terms of the mathematical equation used, the chosen background, and whether the fine fraction or whole sediment matrix is used. This study aims to assess these different methods, propose a new equation to calculate this index and use the index to evaluate the environmental quality of Baixada Santista. The levels of heavy metals were quantified in fifty sediment samples using both in the whole sediment sample and only in the fine fraction. The index was calculated in both fractions and in the normalized levels. Using the fine fraction of the sample was more suitable to the classification. The ratio of the levels in the whole sediment to the fine content did not present a significant statistical difference compared to the levels obtained from the fine fraction. Based on this study, a new equation is proposed for use in future environmental studies.

Assessing the influence of ocean acidification to marine amphipods: A comparative study

CO₂ increases in the ocean may occur both by the capacity of CO₂ exchanges with its dissolved form between atmosphere and surface seawater as well by CO₂ leaks during the carbon capture and storage (CCS) process. The decrease in seawater pH may result in a reduction in the concentration of both hydroxide and carbonate (OH^- and CO₃^2-). The main aim of this work is to conduct an ecotoxicology comparative survey using two amphipod species from Europe and Brazil exposed to different acidification (CO₂) scenarios. For it, an integrative approach based on the weight of evidence was used for comparative proposes to identify the effects on the amphipods association with the acidification and with the related mobility of metals. The results demonstrate that the Ampelisca brevicornis species is more sensitive to pH reductions than the Hyale youngi species. Furthermore, this study has demonstrated that the CO₂ enrichment in aquatic ecosystems would cause changes on the mobility of certain metals (Zn, Cu and As). The results of Principal Component Analysis (PCA) showed that the dissolved Zn in overlying water was strongly correlated with the decrease in the pH and was associated with increased toxicity of the sediment to the exposed organisms, mainly for the A. brevicornis species from Spain. Nevertheless, similar results were found in relation to the mortality of amphipods in low pH values for all sediment tested. Concluding, it is highlighted the importance of comparative studies in different types of environment and improve the understood of the risks associated with the ocean acidification.

Comparative evaluation of sea-urchin larval stage sensitivity to ocean acidification

Changes in the marine carbonate system may affect various calcifying organisms. This study is aimed to compare the sensitivity of embryo-larval development of two species of sea urchins (Paracentrutos lividus and Lytechinus variegatus) collected and exposed to samples from different coastal zone (Spain and Brazil) to ocean acidification. The results showed that the larval stages are very sensitive to small changes in the seawater's pH. The larvae from P. lividus species showed to be more sensitive to acidified elutriate sediments than larvae from L. variegatus sea urchin. Furthermore, this study has demonstrated that the CO₂ enrichment in aquatic ecosystems cause changes on the mobility of the metals: Zn, Cu, Fe, Al and As, which was presented different behavior among them. Although an increase on the mobility of metals was found, the results using the principal component analysis showed that the pH reduction show the highest correlations with the toxicity and is the main cause of embryo-larval development inhibition. In this comparative study it is demonstrated that both species are able to assess potential effects of the ocean acidification related to CO₂ enrichment by both near future scenarios and the risk associated with CO₂ leakages in the Carbon Capture and Storage (CCS) process, and the importance of comparative studies in different zones to improve the understanding of the impacts caused by ocean acidification.

Sediment toxicity identification evaluation (TIE phases I and II) based on microscale bioassays for diagnosing causes of toxicity in coastal areas affected by domestic sewage

Domestic sewage is a major problem in highly urbanized coastal areas worldwide. In the present study, toxicity identification evaluation (TIE) phases I and II were applied to sediment interstitial water from 2 locations along the São Paulo coast in southeastern Brazil: the sewage outfalls from the city of Santos, a densely urbanized area, and the city of Bertioga, a less urbanized area. An adapted microscale sea urchin embryo-larval development bioassay was employed. Phase TIE-I manipulations were 1) ethylenediamine tetraacetic acid (EDTA) addition, 2) aeration at modified pH, 3) C18 solid-phase extraction (SPE), and 4) addition of Na₂ S₂ O₃ . The results of the Santos TIE-I indicated toxicity by sulfides and substances with affinity to C18 resin. In Bertioga, toxicity was the result of NH₃ , metals, and arsenic, as well as substances with affinity to C18 resin. Phase TIE-II aimed to specify the causes of toxicity by testing the toxicity of eluates of the sublation and C18 SPE manipulation. The results reinforced the role of both surfactants and nonpolar compounds as causative agents of toxicity in both Santos and Bertioga. Chemical analyses of sediment interstitial water or whole sediment ruled out the influence of polycyclic aromatic hydrocarbons (PAHs) or polychlorinated biphenyls (PCBs) in the toxicity of both sampling sites. Other hydrophobic substances may play a role in the toxicity of Santos and Bertioga effluents. Efforts to remove such substances from sanitary effluents must be prioritized. Environ Toxicol Chem 2017;36:1820-1832. © 2017 SETAC.

Shell alterations in limpets as putative biomarkers for multi-impacted coastal areas

During the last years, shell alterations in gastropods have been proposed as tools to be used in monitoring programs. However, no studies were so far performed investigating the relationships among shell parameters and classical biomarkers of damage. The relationship between shell alterations (biometrics, shape and elemental composition) and biomarkers (LPO and DNA strand break) was evaluated in the limpet L. subrugosa sampled along a contamination gradient in a multi-impacted coastal zone from southeastern Brazil. Statistically significant differences were detected among sites under different pollution levels. The occurrence of shell malformations was consistent with environmental levels of several hazardous substances reported for the studied area and related to lipid peroxidation and DNA damage. In addition, considering the low mobility, wide geographic distribution, ease of collection and abundance of limpets in coastal zones, this putative tool may be a cost-effective alternative to traditional biomarkers. Thus, shell alterations in limpets seem to be good proxies for assessing biological adverse effects in multi-impacted coastal zones.

Use of a chemometric tool to establish the regional background and assess trace metal enrichment at Baixada Santista - southeastern Brazil

The trace metals in sediments consist of two components, anthropogenic and lithogenic or natural, which can cause misinterpretations for what actually exists in sediments. Normally, to investigate trace metal background levels, indices are applied in order to normalize the values and reduce natural variability, but it is well known that using the average shale or crust content is not the best choice and vertical sediment profiles are not always available. The purpose of this study is to use a prediction interval to assess metal enrichment without a reference level and to assess a regional background level using the same tool. The levels of eight elements were submitted to a partial digestion technique and analyzed by ICP-OES. The enrichment factor results suggested that using background values from the prediction interval and using values from vertical sediment profiles yield statistically similar results. Furthermore, the background equations present more realistic data than other methods because they consider the mud content of the samples. Thus, a prediction interval can be a useful tool to establish a regional background and assess trace metal enrichment.

A systematic quality assessment of Environmental Impact Statements in the oil and gas industry

The global economy relies heavily on oil and gas resources. However, hydrocarbon exploitation projects can cause significant impacts on the environment. But despite the production of numerous Environmental Impact Statements (EISs) to identify/mitigate such impacts, no study has specifically assessed the quality of EISs for both onshore and offshore oil and gas projects, with tested hypotheses. To address this research gap, our paper, for the first time, develops a modified Lee and Colley evaluation model to assess the quality of 19 sampled oil and gas project EISs produced from 1998 to 2008 in Nigeria. Our findings show that Project Description and Communication of Results are the main areas of strength. However, Environmental Impact Prediction, and Project Decommissioning, were among the key areas requiring attention. A key finding, though, is that Mann-Whitney tests suggest that there is no evidence that the quality of EISs for the latter period (2004-2008) is higher than that of the earlier period (1998-2004). We suggest that periodic systematic review of the quality of submitted/approved EISs (c. every 3-5years) should be established to monitor trends in EIS quality and identify strong and weak areas. This would help to drive continual improvement in both the EIA processes and the resultant EISs of technical engineering projects. Such reviews have the potential to illuminate some of the underlying problems of, and solutions to, oil and gas exploration, production and transportation, and their related environmental impacts. This suggested change would also be useful internationally, including for the burgeoning exploration and production of unconventional hydrocarbon resources.

Spatial variability in persistent organic pollutants and polycyclic aromatic hydrocarbons found in beach-stranded pellets along the coast of the state of São Paulo, southeastern Brazil

High spatial variability in polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides, such as DDTs, and polybrominated diphenylethers was observed in plastic pellets collected randomly from 41 beaches (15 cities) in 2010 from the coast of state of São Paulo, southeastern Brazil. The highest concentrations ranged, in ng g(-1), from 192 to 13,708, 3.41 to 7554 and <0.11 to 840 for PAHs, PCBs and DDTs, respectively. Similar distribution pattern was presented, with lower concentrations on the relatively less urbanized and industrialized southern coast, and the highest values in the central portion of the coastline, which is affected by both waste disposal and large port and industrial complex. Additional samples were collected in this central area and PCB concentrations, in ngg(-)(1), were much higher in 2012 (1569 to 10,504) than in 2009/2010 (173 to 309) and 2014 (411), which is likely related to leakages of the PCB commercial mixture.

Dredged material characterization and management frameworks: A case study at the port Vilagarcia (NW, Spain)

The potential impact of dredged sediment has been assessed at sixteen areas of the high-traffic port of Vilagarcia (Northwest Spanish Atlantic coast). The assessment has been done by three weight-of-evidence tools, which integrated data on sediment characteristics and toxicity responses of Ampelisca brevicornis, Vibrio fischeri and eggs and embryos of Paracentrotus lividus. Two of the tools also represented management options regarding the disposal of dredged material. The comparison of the logic in these tools revealed essential differences in the type and the necessity of bioassays and threshold values for chemical concentrations. However, despite this difference, assessment results and the derived management options coincided in most of the sediments. The potential toxicity of sediments was relatively low especially for eggs and embryos possibly due to different contaminant availability in solid and liquid phases. The importance of a battery of toxicity tests in the dredged material quality assessment has been emphasized to avoid an underestimation of sediment toxicity for solid phase organisms, if only liquid phase responses are considered. The potential false implications, which may result from the application of the third tool, were highlighted. The strengths and weaknesses of the tools were discussed from the dredged material management perspective.

Heavy metal spatial variation, bioaccumulation, and risk assessment of Zostera japonica habitat in the Yellow River Estuary, China

Globally, seagrass habitats are decreasing due to both natural and environmental contaminations by human activities, including heavy metal pollution. To expand the global seagrass detection network, this study reports the spatial distributions of Zostera japonica seagrass habitats in the Yellow River Estuary, China. In addition, heavy metal concentrations of Z. japonica tissue, sediment, and surface seawater were analyzed to determine the bioaccumulation and consequent ecological risk to Z. japonica habitats due to the effects of heavy metals. It was found that concentrations of heavy metals were 1.00-2.03 times higher in seagrass-rooted sediment than in adjacent non-seagrass sediment, except for Mn (with a factor of 0.99). Pb and Hg concentrations in sediments exceeded background values more than the other heavy metals, by factors of 1.74 and 1.24, respectively. Metal concentrations in the surrounding seawater were 2.60-4.63 times higher at seagrass sites than at non-seagrass sites, except for Hg (factor of 0.97). Metal concentrations were much higher in seagrass tissues than in the sediment (e.g., bioconcentration factor of Cd is 30.95). Pb concentrations in water may cause the greatest adverse reactions among aquatic organisms, while As, Cr, Hg, Mn and Cu in sediments may occasionally cause negative ecological effects. Z. japonica showed higher bioaccumulation of Cd and Pb in the above-ground tissues. Among other recent studies of seagrasses from other parts of the world, Cd concentrations are similar to the results of the present study, but Pb concentration in present study is higher than in other studies. In conclusion, Pb and As in the surrounding environment present potential risks to the seagrass habitats of the Yellow River Estuary, China.

Environmental risk assessments and spatial variations of polycyclic aromatic hydrocarbons in surface sediments in Yangtze River Estuary, China

In this study, based on sampling data from 30 sites in August 2010, the environmental risks associated with 16 priority PAHs were estimated in surface sediments from the Yangtze River Estuary (YRE). The results indicated that the toxic equivalent quantities of the benzo[a]pyrene (TEQBap) from 30 sites were in the range of 1.93-75.88ngg(-1), and the low-molecular-weight PAHs were the dominated species with higher potential toxicity. The results of the Incremental Lifetime Cancer Risk (ILCR) model indicated that the ILCR values of dermal contact were higher than 10(-6) in the northeast region, suggesting that there were significant potential carcinogenic health risks for fishermen exposure to sedimentary PAHs via dermal contact in these areas. RQ values of PAHs indicated the various distributions of ecological risk levels in the study area. These variations might be caused by the natural and anthropogenic inputs and currents in the YRE.