The increase of pollutants in coastal seawater could produce several harmful biological effects on marine organisms related to the production of reactive oxygen species (ROS) causing cellular and tissue damages through oxidative stress mechanisms. Common octopuses (Octopus vulgaris) inhabiting coastal areas under high anthropogenic activity of Mallorca (W-Mediterranean Sea) have the ability to control oxidative damage by triggering antioxidant enzyme responses. Analyzing the digestive glands, octopuses from human-altered coastal areas showed higher activity of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) compared to octopuses from non-influenced coastal waters (i.e. marine reserve area). Higher metallothionein (MT) concentrations and lack of malondialdehyde (MDA) variations also reflect adaptations of O. vulgaris to polluted areas. This is the first study assessing the levels of the oxidative stress biomarkers on O. vulgaris in the Mediterranean Sea, revealing their usefulness to assess diverse environmental pollution effects on this relevant ecological and commercial species.

Ageing of various plastics in marine environment was monitored after immersion of two synthetic (polyvinylchloride, PVC, and polyethylene terephthalate, PET) and one biodegradable (poly(butylene adipate co-terephtalate), PBAT) plastics for 502days in the bay of Lorient (Brittany, France). Data analysis indicates that aged PVC rapidly releases estrogenic compounds in seawater with a later adsorption of heavy metals; PET undergoes a low weakening of the surface whereas no estrogenic activity is detected; PBAT ages faster in marine environment than PVC. Aged PBAT exhibits heterogeneous surface with some cavities likely containing clay minerals from the chlorite group. Besides, this degraded material occasionally shows a high estrogenic activity. Overall, this study reports, for the first time, that some aged plastics, without being cytotoxic, can release estrogenic compounds in marine environment.

Dimethylsulfoniopropionate (DMSP) is a biogenic compound that could be involved in metal detoxification in both the host and endosymbionts of symbiotic corals. Acropora aspera, a common reef-building coral of the Great Barrier Reef, was exposed to zinc doses from 10 to 1000μg/L over 96h, with zinc being a low-toxic trace metal commonly used in the shipping industry. Over time, significantly lower DMSP concentrations relative to the control were found in both the host and symbionts in the highest zinc treatment where zinc uptake by both partners of the symbiosis was the highest. This clearly indicates that DMSP was consumed or stopped being produced under high and extended zinc exposure. This drop in DMSP was first observed in the host tissue, suggesting that the coral host was the first to respond to metal contamination. Such decrease in DMSP concentrations could influence the long-term health of corals under zinc exposure.

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography–mass spectrometry. Twenty-three samples were collected from the surface sediments of Qinhuangdao coastal wetlands in this survey. This research aimed to identify the PAHs contamination level, composition pattern, pollution sources, and assess the ecological risk of PAHs. The results showed that the sum of PAH concentrations ranged from 341.61ng/g to 4703.80ng/g (mean: 1367.80ng/g), which is higher than the reported values for different wetlands worldwide. Five- and four-ring PAHs (34.08% and 32.97% of Ʃ16PAHs, severally) were predominant in the wetland sediment. The PAH source distribution in the surface sediments was determined using diagnostic ratio and PCA/MLR. Consequently, multiple PAH sources were found. Of the total PAHs, 70.01% was derived from vehicular emission, 25.73% from coke oven, and 4.26% from petroleum-based product spills. The effect range low/effect range median (ERL/ERM) values indicated a low toxicity risk level. However, the DBahA concentrations exceeded the ERL level, and even the ERM level, in some stations. The mean effects range–median quotient (M-ERM-Q) suggests a low ecological risk for the PAHs, but a medium risk for some stations in the coastal wetland sediments.

Ashes settling into the sea from volcanic explosions expose suspension-feeding species to reduced seston quality. Adults and juveniles of the mussel Mytilus chilensis were exposed for 15days to the phytoplankton Isochrysis galbana together with various concentrations of ashes. We then quantified impact on survival and physiology. Although no individuals died during the experiment, by the end of the study clearance rates and oxygen consumption rates had decreased substantially, and tissue weight of mussels exposed to the highest ash concentrations declined substantially. Gills showed no physical damage, but did show abundant mucus secretion in response to ash particles. Moreover, as the relative proportions of microalgae to ash in the diet decreased, individuals showed increasing preferential ingestion of microalgal particles. Increased ash content in the diet altered physiological rates and activated distinct particle selection with a high production of pseudofeces and high energy costs, with potential long-term consequences.

There is global interest in marine renewable energy from underwater tidal turbines. Due to overlap in animal habitat with locations for tidal turbines, the potential for collisions has led to concern around strike risk. Using data from tagged harbor seals collected before construction and after operation of the SeaGen tidal turbine in Northern Ireland, this study quantifies risks of an operational turbine to harbor seals by taking into account turbine characteristics, tidal state, and seal behavior. We found 68% spatial avoidance (95% C.I., 37%, 83%) by harbor seals within 200 m of the turbine. When additionally accounting for variation in seal occupancy over depth and tidal flows, there is an overall reduction in collision risk from 1.29 to 0.125 seals per tidal cycle (90.3% reduction; (95% C.I., 83%, 98%)) compared to risk calculated under assumptions of uniform habitat use. This demonstrates the need to incorporate environmental conditions to properly assess strike risk.

Polycyclic aromatic hydrocarbons (PAHs) were measured in environmental samples (sponges, fish and sediment) collected in 2014 and 2016 from the Faroe-Shetland Channel and Rosemary Bank Seamount. These data could be used to provide a baseline against which any changes can be assessed in the event of an oil spill and contribute to any environmental impact assessment. Concentrations in all samples were low, often below the detection limits, and were typical of reference sites. Sponges can be used as an alternative indicator species to mussels for monitoring PAHs in the marine environment as they can accumulate PAHs from both the dissolved and particulate phase. PAH concentrations in marine sponges from Scottish waters have not previously been reported. Concentrations were low, but contained a higher proportion of heavier 4- to 6-ring PAHs compared to the fish samples.

Sandy beaches are sites of marine debris stranding, but the interaction of beach biota with waste is poorly studied. The objective of this study was to investigate whether the ghost crab Ocypode quadrata selects marine debris by types using a non-destructive method on sandy beaches of Southeastern Brazil. We found marine debris in 7% of 1696 surveyed burrows, and the ghost crabs selectivity was mainly by soft plastic (30%), straw (11%), rope (6%) and foam (4%). Burrows with marine debris showed higher occupation rate (~68%) compared to burrows without debris (~28%), indicating that these materials may increase the capacity of ghost crabs to memorize their burrows placement (homing). The percentage of marine debris was not always related to their amount in the drift line, but ghost crabs used more debris near urbanized areas. Future studies should test whether ghost crabs are using marine debris for feeding, homing or other mechanisms.

The most common lead (Pb) and zinc (Zn) ore minerals are galena (PbS) and sphalerite (ZnS). Milling and mining operations of these ores produce huge amounts of waste known as chat and tailings. Chat is composed of gravel, sand, and silt-sized rock materials, whereas tailings are often fine-grained and silt-sized particles with higher toxic element concentrations. Upon oxidation, tailings with high pyritic materials release Pb, Zn, Cadmium (Cd), and other elements associated with ores affecting plant productivity, the ecosystem, and human health. This article is an overview on utilizing the subsurface submergence technique for mitigating environmental impacts from abandoned mine waste materials. In the past, researchers have studied the influence of submergence on these elements; however, an emphasis on gathering a detailed understanding of such redox-based remediation processes is not that common. We reviewed literature that evaluated water chemistry, solid phases, and association of trace elements, and addressed utilization of surface amendments of mine tailings for predicting their interactions within sediments and overlying waters. Case studies specifically focused on mining of Pb and Zn, including a recent study conducted in the Tri-State mining district (Kansas, Missouri, and Oklahoma), are presented to add a more comprehensive understanding of biogeochemical transformations of trace elements present in mine waste materials under a long-term submergence. The purpose of this article is to present evidence on the viability of subsurface disposal of mine waste materials, in order to design effective remediation and mitigation strategies to protect human and environmental health in the global dimension.

The distribution characteristics, sources and ecological risk of antimony (Sb) in the surface sediments of Changjiang Estuary and the adjacent sea were studied. Sb concentrations ranged from 0.320 to 0.968 μg g−1 with mean value of 0.577 μg g−1. Sb concentrations were relatively high in sediments of the south Yellow Sea, the Hangzhou Bay mouth and the inner Changjiang Estuary. The variation trend of Sb concentrations was controlled by hydrodynamics, Al/Fe/Mn oxides. Sb also showed strong chalcophile property. Correlation analysis and enrichment factor showed Sb came mainly from natural sources. Total Sb sediment flux in the study area was 446.3 t/yr. The Changjiang River, the Yellow River and atmospheric inputs accounted for 85.7%, 13.9%, and 0.4% of the total sediment Sb flux, respectively. The result of potential ecological index indicated the very low Sb concentrations could hardly threat the ecological environment of the study area.