In this study, Acid-Volatile Sulfur (AVS), trace metals Cu, Cd and Zn and their chemical speciation based on BCR-sequential and simultaneous extraction (SEMs) in Antarctic lake sediments (Y2-1 and YO) were analyzed to investigate the restriction of sulfate reduction on the bioavailability and toxicity of trace metals. Much higher trace metals in Y2-1 indicating a primary source from penguin guano. The main chemical speciation of Cu and Cd in Y2-1 was their oxidizable fraction in contrast to those of weak-acid extraction in YO. Lower ratio of ΣSEM/AVS in Y2-1 indicating less toxicity of the trace metals. The main chemical speciation of Cd in Y2-1 was their oxidizable fraction in contrast to that exchangeable fraction in penguin guano, indicating that although amounts of Cd was transported from marine to lake by penguins, strong sulfate reduction in ornithogenic sediments restricts the bioavailability and toxicity of Cd through the formation of insoluble sulfide. PCBs and PBDEs in microplastics and zooplankton collected in surface water at 27 locations in the Pacific Ocean and around the coast of Japan were investigated. Both PCBs and PBDEs were observed in buoyant microplastics, even in smaller particles of 0.315-1 mm. Concentrations of Σ13 PCBs were 0.04-124 ng/g, and were higher in urban bay areas such as Tokyo Bay. Sporadic moderate to high concentrations of PBDEs were observed in both urban-offshore and rural-offshore locations, consisting mostly of higher-brominated congeners. From the latter, BDE 209 ranged from not detected to 2158 ng/g. The microplastic-to-zooplankton abundance ratio threshold was 0.6 for PCBs and 0.08 for PBDEs, above which exposure would be greater from microplastics than from zooplankton. Here, we report results from a 15-day mesocosm experiment examining changes in estimated oil equivalents (EOEs), n-alkanes (n-C10 to n-C35), polycyclic aromatic hydrocarbons (PAHs) and petroleum biomarkers. Water accommodated fractions (WAF) of oil and diluted chemically enhanced WAF (DCEWAF) were prepared and concentrations of oil residues determined on day 0, 3 and 15, respectively. Significant removals of n-alkane and PAHs were observed starting from day 3. The n-C17/pristane and n-C18/phytane ratios suggested that the n-alkane removal was due to biodegradation in the mesocosms. The ratios of C2-dibenzothiophenes/C2-phenanthrenes (D2/P2) and C3-dibenzothiophenes/C3-phenanthrenes (D3/P3) were found to be stable through the experiment. DCEWAF treatment had longer half-lives for most n-alkanes but shorter half-lives for most PAHs than the WAF treatment. Most petroleum biomarkers were stable throughout the experiment. However, depletion of TAS (tricyclic aromatic steroids) was observed on day 15 of DCEWAF treatment. The daily accumulation rates, composition, sizes and potential sources of marine litter collected on a remote island within the Western Indian Ocean were investigated. In total, 9119 items of marine litter were collected during 40 surveys, which equated to 0.0082 items·m-1·d-1. Between 2003 and 2019 there was a significant increase in the amount of litter deposited, with the highest daily accumulation rate recorded in 2019 (0.0255 items·m-1·year-1). All specific litter types increased over time and also differed significantly in their accumulation rates, with polystyrene fragments/pieces (0.00249 items·m-1·d-1), plastic items (0.00135 items·m-1·d-1) and plastic bottles (0.0011 items·m-1·d-1) being the most commonly encountered during this study. The majority of the litter found was ≤5 cm in size. Nearly all (>80%) litter collected was made of or contained some form of plastic. Recommendations for improved management of litter and the importance of establishing regular beach clean-ups within the Seychelles are briefly discussed. In assessing the overall status of individual water bodies the EU Water Framework Directive (WFD) requires member states to assess both ecological and chemical status. The ecological status of transitional and coastal (TraC) waters is based on the assessment of specific biological elements as well as supporting chemical, physico-chemical and hydromorphological elements. Hydromorphology of TraC waters is one of the basic features of marine and coastal ecosystems controlling the presence of biota. Human induced hydromorphological alterations and pressures can damage the ecology and functioning of aquatic ecosystems. Thirteen metrics were developed and combined to form a hydromorphological index, the Hydromorphological Quality Index (HQI). The index categorises a water body into 5 classes. Semi-qualitative and quantitative criteria were used to assign a morphological classification directly related to that of the WFD, i.e., high, good, moderate, poor and bad. Thirty-three transitional and coastal water bodies were assessed using HQI. We investigated the growth and nutrient uptake of Myriophyllum spicatum under different nutrient conditions and evaluated its implications for ecosystem services in an enclosed area of Jinshan. https://www.selleckchem.com/products/filanesib.html The specific growth rate ranged from 1.29%-4.37%/day, and the dissolved inorganic carbon and nitrogen, and phosphorus uptake rates were 1.30-1.62, 0.040-0.453, and 0.003-0.027 mg/(g∙day), respectively, under different nutrient conditions. The O2-production and carbon-sequestration efficiencies in the field were 154.30 and 1.25 mg/(g DW∙h), respectively. The average removal efficiencies of NH4+-N, NO3--N, NO2--N, and PO43--P were 43.05%, 97.03%, 64.26%, and 59.24%, respectively, in M. spicatum-cultivated areas compared with in the open sea. Harvesting of M. spicatum removed 12,936.87, 1289.97 and 114.81 kg of carbon, nitrogen, and phosphorus, respectively, from seawater in Jinshan in Nov, 2018. In conclusion, M. spicatum is a good candidate for integrated macrophyte/animal multi-trophic aquaculture in terms of nutrient extraction and economic diversification in low-salinity environments. Few investigations of iron speciation exist in intertidal conditions with little attention given to understanding the geochemical behavior of Fe3+-Fe2+ and its biogeochemical processes. Here, one sediment core was collected in Yunxiao mangrove forests, Zhangjiang estuary, China and iron mineralogy was determined by magnetic methods and Mössbauer spectroscopy. Changes in magnetic susceptibility, susceptibility of anhysteretic remanent magnetization, and saturation isothermal remanent magnetization were linked to changes of pseudo-single domain soft coercive components with minor antiferromagnetic fractions and the presence of minimal concentrations of superparamagnetic particles was confirmed by the no frequency dependent of AC magnetization. A positive correlation between L-ratio and hard isothermal remanent magnetization is congruent with the distribution of high-coercivity antiferromagnetic minerals. At 295 K, the Mössbauer spectrum of specimens was well fitted with a single magnetic sextet, hematite and two magnetic doublets, paramagnetic Fe2+ and paramagnetic Fe3+.