Hennebergsalinas4737

The release of oil and gas at Mississippi Canyon Block 20 into the Gulf of Mexico has vexed response officials since 2004 when a regional seafloor failure toppled the Taylor Energy Company platform. Despite the completion of nine intervention wells, releases continue from the seafloor, mostly captured by a recently installed containment system. Toward informing resolution, this work applies chemical forensic and statistical analyses to surface sheens, sediments, and reservoir oil samples. Our results indicate sheens are chemically heterogeneous, contain remnant synthetic hydrocarbons likely discharged from well interventions prior to 2012, and require mixing of multiple chemically-distinct oil groups to explain observed variability in diagnostic ratios. Given the respite and opportunity afforded by containment we suggest leveraging ongoing collection activities to assess release dynamics, as well as engaging the National Academies of Science, Engineering, and Medicine, to evaluate potential solutions, associated risks, and to consider policy ramifications.Determining the overall effects of human activities on the estuaries, seas and coasts, as a precursor to marine management, requires quantifying three aspects. These are (a) the area in which the human activities take place, (b) the area covered by the pressures generated by the activities on the prevailing habitats and species, in which pressures are defined as the mechanisms of change, and (c) the area over which any adverse effects occur. These features can be respectively termed the activities-footprints, the pressures-footprints and the effects-footprints. The latter in turn incorporates both the effects on the natural system and the effects on ecosystem services from which society extracts goods and benefits. This viewpoint article explains the rationale behind this typology and proposes definitions for each of these three types of footprints.We examined the spatial distribution and local characteristics of microplastics (0.33-5 mm) in surface water from six semi-enclosed bays and two coastal waters in Korea. Surveys were conducted in July from 2015 to 2017 using a Manta trawl. The mean abundance of total microplastics ranged from 1.12-4.74 particles/m3 among sites; the microplastics were mostly expanded polystyrene (EPS), paint particles, fragments and fibers. The mean microplastic abundance (2.85 particles/m3) in urban areas was about 1.5 times higher than in rural areas (1.86 particles/m3) (p less then 0.05). EPS dominated at rural sites, while fragments, paint particles, and fibers were relatively more dominant in urban areas. The different types and quantities of microplastic particles indicated that the region-specific occurrence of microplastics is likely to be related to differences in human activities between urban and rural areas, even though fibers were distributed throughout the study area.Shark fin is one of Asia's most valued dried seafood products, with over 80 shark species traded in Hong Kong [HK]. NSC697923 solubility dmso We analyzed processed shark fins from mainland China and HK markets (n = 267) for mercury, methyl‑mercury, and arsenic, to inform consumers, policy makers and public health officials on the health risks of ingesting fins from nine of the most common shark species in the fin trade. Fins from all species frequently exceed Hg limits established by HK authorities. Most of the mercury found is in the form of methyl‑mercury (69.0 ± 33.5%). Five species surpass methyl‑mercury PTWIs and blue shark fins can exceed inorganic arsenic BMDL0.5. Species-of-origin was a significant predictor of heavy metal concentrations, with higher mercury concentrations associated with coastal sharks and lower arsenic levels found with increasing shark trophic level. Species-specific labeling would help consumers avoid shark fin products that pose the highest health risk.Marine litter levels were measured in the stomach contents, hepatopancreas, and gonad tissues of crustacea decapod (Callinectes sapidus Rathbun, 1896; n = 6), a widespread alien species affecting the Lesina lagoon. Results highlight a mean of 2.5 (SD = 1.6) items/animal and indicate the presence of metals fragments (13%) and plastics (13% PE; 6.7% PET) in the stomach contents of collected individuals. No microplastic particles were detected in the hepatopancreas or in muscle tissue, while microplastic fibres (nylon, rayon, polyester) were found present in female specimen gonads. The presence of synthetic fibres in the investigated species reflects the relative contamination level in this habitat type and suggests that the blue crab could be considered a model organism for evaluating the contamination status of the study area.In the present study, a modified water quality index (WQI) was used to evaluate the water quality in south coastal aquaculture area of Dalian, Liaoning Province, China. Four main culture areas with 40 sampling stations were covered. Ten variables were selected for principal component analysis/factor analysis (PCA/FA), and the major factors affecting water quality were identified. The PCA results showed that these factors were mainly associated with nutrients, natural conditions and organic matter. The modified WQI was calculated to identify the classes of water quality and to evaluate the spatial and temporal changes among the sampling areas. The results revealed that the water quality generally performed the worst in June, and the best in October. The modified WQI proved to be a useful method for water quality classification and characterizing spatial and temporal changes in Dalian aquaculture areas.Aluminum smelter-derived polycyclic aromatic hydrocarbons (PAHs) in outmigrant juvenile Chinook salmon were evaluated in Kitimat Arm, British Columbia, Canada from 2000 to 2004, and in 2015. Decades of continual smelter operations by Rio Tinto resulted in PAH contamination of marine sediments at levels associated with adverse effects in juvenile salmon. Recently, smelter operations have undergone process changes to reduce PAH input to the environment. The PAH concentrations in juvenile Chinook salmon observed in 2000 to 2004, at sites nearest the smelter were comparable to salmon in other urban areas where reduced disease resistance was observed; the levels were lower in 2015 than 2000-2004 suggesting that the recent process changes were effective. Further, these data establish a benchmark for assessing any future changes affecting PAH input and the potential risks to the receiving environment.