Derelict fishing gear is a source of mortality for target and non-target marine species. A program employing commercial watermen to remove marine debris provided a novel opportunity to collect extensive spatially-explicit information for four consecutive winters (2008–2012) on the type, distribution, and abundance of derelict fishing gear and bycatch in Virginia waters of Chesapeake Bay. The most abundant form of derelict gear recovered was blue crab pots with almost 32,000 recovered. Derelict pots were widely distributed, but with notable hotspot areas, capturing 40 species and over 31,000 marine organisms. The target species, blue crab, experienced the highest mortality from lost pots with an estimated 900,000 animals killed each year, a potential annual economic loss to the fishery of $300,000. Important fishery species were captured and killed in derelict pots including Atlantic croaker and black sea bass. While some causes of gear loss are unavoidable, others can be managed to minimize loss.

Surface sediments collected along the entire continental shelf of China, including Yellow Sea, the East China Sea (ECS) inner shelf and the South China Sea (SCS), were analyzed for linear alkylbenzenes (LABs), from which regional anthropogenic influences on the marine environment were assessed. The occurrence of LABs (5.6–77ng/g; mean: 25ng/g; median: 20ng/g) implied light sewage contamination in coast sediment off China. Specifically, the SCS had higher sedimentary LAB levels than Yellow Sea and the ECS inner shelf, which was mainly related to the intensity of domestic wastewater discharge and marine fishing activities. Values of L/S and C13/C12 (defined in the main text) suggested certain degradation while I/E indicated limited degradation of LABs. Also, additional input sources and congener inter-conversions may have contributed to the inconsistent results for degradation of LABs in offshore sediments. Atmospheric inputs and wastewater discharge from marine fishing vessels predominantly contributed to sedimentary LABs in Yellow Sea and the SCS, while riverine input was mainly responsible for LABs along the ECS inner shelf.

The North-East Atlantic porbeagle (Lamna nasus) population has declined dramatically over the last few decades and is currently classified as ‘Critically Endangered’. As long-lived, apex predators, they may be vulnerable to bioaccumulation of contaminants. In this study organohalogen compounds and trace elements were analysed in 12 specimens caught as incidental bycatch in commercial gillnet fisheries in the Celtic Sea in 2011. Levels of organohalogen contaminants were low or undetectable (summed CB and BDE concentrations 0.04–0.85mgkg−1wet weight). A notably high Cd concentration (7.2mgkg−1wet weight) was observed in one mature male, whereas the range observed in the other samples was much lower (0.04–0.26mgkg−1wet weight). Hg and Pb concentrations were detected only in single animals, at 0.34 and 0.08mgkg−1wet weight, respectively. These contaminant levels were low in comparison to other published studies for shark species.

Phosphorus (P) in surface sediments of the Laizhou Bay (LB) and the coastal waters around the Zhangzi Island (ZI) was analyzed. Six forms of P were separated — exchangeable or loosely sorbed P (Ads–P), aluminum-bound P (Al–P), iron-bound P (Fe–P), authigenic apatite plus CaCO3-bound P plus biogenic apatite (Ca–P), detrital apatite plus other inorganic P (De–P) and organic P (OP). The average contents of P in the LB were in the order: De–P>OP>Ca–P>Fe–P>Ads–P>Al–P; in the ZI, the corresponding order was De–P>OP>Fe–P>Ca–P>Ads–P>Al–P. Due to the high nutrient loadings from the surrounding rivers, TP contents in sediments of the LB were higher than in those of the ZI. The potential bio-available P (Ads–P and OP) accounted for 14.7% and 24.2% of TP in sediments of the LB and the ZI, respectively.

Carbon and nitrogen stable isotopes in albatrosses and petrels collected off southern Brazil were compared with concentrations of organochlorine contaminants (OCs). δ13C and δ15N values, as well as OCs concentrations, exhibited a high degree of variability among individuals and overlap among species. δ13C values reflected latitudinal differences among species, with lower values found in Wandering and Tristan Albatrosses and higher values found in Black-browed and Atlantic Yellow-nosed Albatrosses and White-chinned Petrels. Some relationships were found between OCs and stable isotopes, but in general a partial ‘uncoupling’ was observed between OCs concentrations and stable isotopes ratios (especially for δ15N). δ13C and δ15N values in Procellariiformes tissues during the non-breeding season appear to be a better indicator of foraging habitats than of trophic relationships, which may partially explain the high degree of variability between concentrations of OCs and stable isotopes ratios in birds with a diversified diet and wide foraging range.

A flexible 2D/3D oil spill modeling system addressing the distinct nature of the surface and water column fluids, major oil weathering and improved retention/reposition processes in coastal zones is presented. The system integrates hydrodynamic, transport and oil weathering modules, which can be combined to offer different-complexity descriptions as required by applications across the river-to-ocean continuum. Features include accounting for different composition and reology in the surface and water column mixtures, as well as spreading, evaporation, water-in-oil emulsification, shoreline retention, dispersion and dissolution. The use of unstructured grids provides flexibility and efficiency in handling spills in complex geometries and across scales. The use of high-order Eulerian–Lagrangian methods allows for computational efficiency and for handling key processes in ways consistent with their distinct mathematical nature and time scales. The modeling system is tested through a suite of synthetic, laboratory and realistic-domain benchmarks, which demonstrate robust handling of key processes and of 2D/3D couplings. The application of the modeling system to a spill scenario at the entrance of a port in a coastal lagoon illustrates the power of the approach to represent spills that occur in coastal regions with complex boundaries and bathymetry.

Four popular, recreational beaches in Miami, FL are Hobie Beach, Virginia Key Beach, Crandon Park Beach, and Bill Baggs Cape Florida State Park. While all of the beaches are within a few miles of each other in Biscayne Bay, they have greatly differing water qualities, as determined by the testing for fecal indicator bacteria performed by the Florida Department of Health. Using the geodesic theory of transport barriers, we identify Lagrangian Coherent Structures (LCSs) in each area. We show how these material curves, which shape circulation and mixing patterns, can be used to explain the incongruous states of the water at beaches that should be comparable. The LCSs are computed using a hydrodynamic model and verified through field experimentation at each beach.

To assess risks of chemically-dispersed oil to marine organisms, oil concentrations in the water were simulated using a hypothetical spill accident in Tokyo Bay. Simulated oil concentrations were then compared with the short-term no-observed effect concentration (NOEC), 0.01mg/L, obtained through toxicity tests using marine diatoms, amphipod and fish. Area of oil concentrations higher than the NOEC were compared with respect to use and non-use of dispersant. Results of the simulation show relatively faster dispersion near the mouth of the bay compared to its inner sections which is basically related to its stronger water currents. Interestingly, in the inner bay, a large area of chemically-dispersed oil has concentrations higher than the NOEC. It seems emulsifying oil by dispersant increases oil concentrations, which could lead to higher toxicity to aquatic organisms. When stronger winds occur, however, the difference in toxic areas between use and non-use of dispersant is quite small.

The effect of different concentrations of NaCl, 0, 100, 200, 300 and 400mM, on the anatomical features and physiology of Myoporum bontioides was investigated. The photosynthetic rates (Pn) were significantly reduced by salt stress, with the lowest values at 400mM NaCl. The content of malondialdehyde (MDA), proline and soluble sugar, as well as the activities of peroxidase (POD) and catalase (CAT) increased at the beginning, but became similar to the control as the experiment proceeded. The NaCl effect on superoxide dismutase (SOD) was different from the other parameters, with a significant reduction at 400mM NaCl at Day 7. Salt glands were found in both upper and lower epidermis, and the ratios of the thickness of palisade to spongy mesophyll tissues increased with NaCl concentrations. The medullary ray was clearly damaged by NaCl at levels of 200 and 300mM. These results demonstrated that M. bontioides could adapt to a relatively low salinity, and was not a halophilous species.

Molecular analysis was applied to characterize bacterial community structure in sediment samples collected from pristine site and oil-polluted Black Sea harbor. Amplified Ribosomal DNA Restriction Analysis (ARDRA) revealed a high similarity in the restriction patterns of both samples thus not demonstrating the effect of the pollutant on the structure of the bacterial communities. Constructed 16S rRNA gene libraries gave more detailed assessment of members. Results showed that α- and γ-Proteobacteria were dominant in the oil polluted site, whereas the pristine site was characterized by prevalence of Actinobacteria. The biodegradative potential of the adapted bacterial community in the oil-polluted sediments was demonstrated by the presence of the aromatic ring hydroxylating dioxygenase genes.