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[en] Highlights: • Proposals are set out to improve the monitoring of dumping sites. • Comparison of the efficiency of sampling strategies used to monitor a dumping site. • Study of the influence of sediment sampling replicates on confidence of results. • Sediment replicates to be sampled are linked to the environmental context. • The number of replicates is dependent on the prevailing environmental conditions. - Abstract: Dredged sediments have different physical and chemical characteristics compared with the sediments in place, which generates multiple effects on the environment. In this study, we show that the sampling strategy used to monitor the effects of dredge spoil deposition on the surrounding environment can lead to different interpretations. It appears that sediment sample replicates may or may not be necessary, depending on the studied area, the prevailing environmental forcings before sediment sampling and the combination of these two factors. The proposed modus operandi allows us to optimize both the confidence on the obtained results and the cost of the sediment studies (sampling and laboratory analyses). The results are based on the sediment fine fraction, which is considered as a key environmental component due, for example, to its strong association with the structure of benthic faunal communities as well as its role in the build-up of pollutants.
[en] Highlights: • Marine debris in the Canary Islands was documented over an annual cycle. • High seasonal variability above an order of magnitude was found. • Coastal orientation, local wind and waves determined debris concentration. • Tar and resin-pellet pollution was high in two beaches. • The type of debris found indicated an open-sea source. - Abstract: Marine debris accumulation was analyzed from three exposed beaches of the Canary Islands (Lambra, Famara and Las Canteras). Large microplastics (1–5 mm), mesoplastics (5–25 mm) and tar pollution were assessed twice a month for a year. There was great spatial and temporal variability in the Canary Island coastal pollution. Seasonal patterns differed at each location, marine debris concentration depended mainly of local-scale wind and wave conditions. The most polluted beach was Lambra, a remote beach infrequently visited. The types of debris found were mainly preproduction resin pellets, plastic fragments and tar, evidencing that pollution was not of local origin, but it cames from the open sea. The levels of pollution were similar to those of highly industrialized and contaminated regions. This study corroborates that the Canary Islands are an area of accumulation of microplastics and tar rafted from the North Atlantic Ocean by the southward flowing Canary Current.
[en] The objective of this study was to evaluate the distribution pattern of persistent organic pollutants in water, sediment and aquatic biota represented by Oreochromis niloticus and Donax trunculus at the Rosetta Nile branch estuary. α-HCH, p,p′-DDE and polychlorinated biphenyls were the predominant compounds detected at ranges of 0.54–4.90 ng/l water, 0.75–2.41 ng/g, d. wt. sediment and 2.19–28.11 ng/g, fresh wt. biota. β and γ-HCHs, endosulfan compounds, heptachlor and heptachlor epoxide were at low detection frequencies. Totally, the organochlorine pollutants were at high levels and abundances in Donax spp. than in Tilapia spp. followed by sediment and water. These levels were ranged between lower and higher than those found by the other studies established in Egypt, and well below its tolerable residue levels in fish. A correlation was found for the quantified pollutants between water, sediment and biota. This is clearly reflecting the bioaccumulation properties of these compounds.
[en] Highlights: • Lead and mercury were the most toxic heavy metals to bivalves. • Copper and cadmium were the most frequently studied heavy metals. • Essential heavy metals (Cu, Zn, Cd) do not necessarily exhibit lower toxicity. • Duration and concentration of exposure did not have a clear effect on toxicity. • Cellular level effect sizes were larger than physiological/population effects. - Abstract: Bivalves are commonly used as biomonitors for heavy metal pollution in marine environments because they accumulate heavy metal ions quickly, are sessile, abundant, and widely dispersed, and adult mortality from contamination is rare. However, the breadth of experiments used to measure the effect of heavy metal contamination can obscure general trends. It is unclear which heavy metals cause the most severe effects, how severity varies with exposure concentration and duration, and whether effects vary with level of biological organization. I conducted a meta-analysis of 48 mesocosm studies on the effects of heavy metal ions – silver, cadmium, copper, mercury, lead, and zinc – on marine bivalves. The ordering of effect sizes was Pb > Hg > Cu > Zn > Cd > Ag. The significance and direction of concentration and duration as moderators depended on the metal and the biological level. Future studies should consider non-linear effects over time and concentration, and measure both bioaccumulation and effect of the metals being studies.
[en] Highlights: • An initial risk assessment of microplastic pollution in surface waters found that there was a higher pollution risk in the East China Sea compared with the Changjiang Estuary. • Polyvinyl chloride was found to be the most serious chemical hazardous microplastic polymer. • The risk of microplastic pollution depends on both concentration distribution and the chemical properties of polymers. - Abstract: The rapid development of plastic industry has resulted in a series of environmental problems caused by microplastics originating from larger plastics. Microplastic pollution risk in surface waters of the Changjiang Estuary was explored based on risk assessment models. The average microplastic concentration was 23.1 ± 18.2 n/100 L. Shape, size, color and composition types of microplastics were examined. The risk assessment models were developed using data on both the concentration and chemical hazard of microplastic polymers. Assessment results indicated that polyvinyl chloride exhibited a critical concern for microplastic risk. Areas around aquaculture farms were regarded as “hotspots” of microplastic pollution due to the accumulation of microplastics and the presence of hazardous microplastic. This risk assessment of microplastics bridged gaps in understanding between field research and policy-making for surface waters. This research provides baseline data for assessing the environmental risk of microplastics in this growing area of research.
[en] Highlights: • Muara Kamal water and sediment is polluted by heavy metals and organic materials. • Concentrations of Hg, Cr6+, Pb, Cd and Sn were exceeded the water quality standard. • Organic fractions and low pH make heavy metals more bioavailable. • Bioavailability and toxicity of the heavy metals absorbed by the mussels • About 60% of cultured green mussel is reported having shells malformation. - Abstract: Jakarta Bay has become contaminated by both organic and inorganic pollutants, including heavy metals. This study aimed to examine the effect of heavy metal pollution on green mussels cultured in Muara Kamal Waters, Jakarta Bay over seven months. In this research, the water quality was assessed, through measuring the concentrations of the heavy metals, Hg, Pb, Cd, Cr, and Sn in the water, and in the tissue of green mussels that had been cultured there for seven months. The percentage of congenital abnormalities (malformations) in the green mussels was analyzed descriptively and the relationship between the water quality, heavy metals, and green mussel malformation was studied through principal component analysis (PCA). The result showed that the heavy metals concentrations in the water and sediment exceeded the quality standard at Muara Kamal but that in other respects the water quality was quite good. The green mussels cultured there for seven months had accumulated high concentrations of heavy metals, and ±60% of them had malformations of their shells. Based on the heavy metal concentrations in their bodies, the main cause of malformations in green mussels was suspected to be Pb, Hg, and Sn. However, the result of PCA showed it was the interaction between nitrogen compounds, phosphate, turbidity, salinity, pH, as well as the heavy metals in the water that determined the green mussel abnormality.
[en] Highlights: • Biomarkers were evaluated in oysters from estuarine areas with different urban influences. • Higher linear alkylbenzene levels were found in areas with higher urban influence. • Oysters from polluted areas showed higher CYP2-like2, GSTΩ and FABP transcript levels. • Pollutants decreased CYP2-like1 and CAT-like transcript levels and caused oxidative stress. - Abstract: Biochemical and molecular responses were evaluated in oysters Crassostrea brasiliana collected from three oyster farms, at Guaratuba Bay, southern Brazil, forming a pollutant gradient: Farm 1 (reference site - farther from the urban area), Farm 2 (intermediate site) and Farm 3 (nearest to the urban area). Oxidative stress markers, DNA damage and transcript levels of CYP2AU1, CYP2-like1, CYP2-like2, SULT-like, GPx-like, SOD-like, CAT-like, GSTmicrosomal-like, GSTomega-like, FABP-like and ALAd-like genes were analyzed in the gills. The levels of polycyclic aromatic hydrocarbons, linear alkylbenzenes and polychlorinated biphenyls were also evaluated in the soft tissues of the oysters and in the sediment of the Farms. Higher GSTomega-like, CYP2AU1 and FABP-like transcript levels, GR and G6PDH activities and lipid peroxidation levels were observed in oysters from Farms 2 and 3, suggesting pollutant effects on oysters. Alterations in oxidative stress markers also suggest a response against a prooxidant condition in C. brasiliana due to pollutant effects.
[en] Highlights: • An alternative to ex situ bioassays in lab to bioaccumulation assessment of metals. • We estimated the metals incorporation rate using only three sizes of A. brasiliana. • Metal incorporation rates during asymptotic growth up decrease with size/age. • The results were consistent with geochemistry processes from four bays. • The approach is reliable to predict potential risk for human consumption. - Abstract: We present an alternative approach for establishing in situ bioaccumulation assessment of methyl-Hg (MeHg), total-Hg, Cd, Pb and Zn in bivalve Anomalocardia brasiliana from four bays of Rio de Janeiro presenting varying degrees of eutrophication, acid volatile sulfides (2–55 μmol g−1), simultaneously extracted metals (SEM) and total metals (TM) in sediments. Using metal concentrations of composite samples from three size classes of bivalve and their incorporation rates (IR = metal concentration / total length), which depend on exposure time, we calculated asymptotic IR and respective consequent metal concentrations. Both IR and the metal concentration presented inverse relationships with total length (excepting MeHg) and bay contamination. Lead and zinc concentrations were above Brazilian legal criteria in the most anoxic and contaminated bay, suggesting significant metal bioavailability (SEM/TM between 8% and 63%).
[en] Highlights: • 2DE were carried out on contaminated mussels after acclimation and acute heat stress. • High mortality rate were observed for non-acclimated mussels. • Acclimated mussels show enhanced stress protein expressions. • Surviving mussels exhibited a main distress signal associated with truncated proteins. - Abstract: Intertidal sessile organisms constitute through their life history unintended stress recorders. This study focuses on the impact of pollution on Mytilus edulis ability to cope with an additional stress. For this purpose, two acclimation stages to different temperatures were conducted before an acute stress exposure in mussels collected from a heavily polluted site. Gill proteomes were analyzed by 2DE and regulated proteins identified. Massive mortality was observed for organisms acclimated to colder temperatures. Despite this major difference, both groups shared a common response with a strong representation of proteoforms corresponding to “folding, sorting and degradation” processes. Nevertheless, surviving mussels exhibit a marked increase in protein degradation consistent with the observed decrease of cell defense proteins. Mussels acclimated to warmer temperature response is essentially characterized by an improved heat shock response. These results show the differential ability of mussels to face both pollution and acute heat stress, particularly for low-acclimated organisms.
[en] Highlights: • The activity concentrations of 137Cs and 40K for sea snail samples were determined. • The radiological hazard parameters due to the consumption of sea snails were calculated. • The lifetime cancer risk values are low for radiological risk. - Abstract: The aim of this study was to determine the activity concentrations and radiological hazard parameters of 137Cs and 40K in soft tissue samples of sea snails (Rapana venosa) collected from 12 different stations in the East Black Sea coastal area of Turkey. The values in soft tissues of sea snail samples with three different sizes were between 0.31 and 1.79 Bq kg−1 for 137Cs and 163.9 and 269.4 Bq kg−1 for 40K. The mean activity concentrations of 137Cs and 40K in tissues of small-sized sea snails were determined to be higher than those of 137Cs and 40K in soft tissues of the other sizes. The determined activity concentration values were lower than the concentrations reported in similar studies. Radiological hazard parameters such as the daily intake (Dint) of 137Cs and 40K, annual committed effective dose (Eeff), and lifetime cancer risk (LCR) were calculated and compared with the international recommended values.