Industrial pressures suffered by estuarine zones leave a pollution record in their sediment. Thus, high concentrations of many heavy metals and some organic compounds are often found in estuarine sediment. This work aims to contribute to the enhancement of water quality management strategies in these zones by studying in detail the diffusive processes that take place between the water and sediment using a two-pronged approach: experimental practice and numerical simulation. To provide an example of the practical application of the methodologies proposed in this paper, the Suances Estuary (northern Spain) was selected as the study zone. This estuary exhibits significant historical pollution and its sediment acts as a continuous internal source of zinc, mainly due to diffusive processes derived from the concentration gradient between the interstitial water at the solid particles of the sediment and the bottom of the water column. The experimentally obtained results, based on 6 case studies, demonstrated the buffering capacity of the system and allowed the determination of the required time for the mass transfer processes to reach an equilibrium state. Furthermore, the diffusion rate of zinc was approximately modeled taking into consideration the high concentration variability observed in sediment along the entire estuary. The convergence between the modeled and the experimental results indicated the required contact time to reach an equilibrium state in a real field situation.

Underwater noise, whether of natural or anthropogenic origin, has the ability to interfere with the way in which marine mammals receive acoustic signals (i.e., for communication, social interaction, foraging, navigation, etc.). This phenomenon, termed auditory masking, has been well studied in humans and terrestrial vertebrates (in particular birds), but less so in marine mammals. Anthropogenic underwater noise seems to be increasing in parts of the world's oceans and concerns about associated bioacoustic effects, including masking, are growing. In this article, we review our understanding of masking in marine mammals, summarise data on marine mammal hearing as they relate to masking (including audiograms, critical ratios, critical bandwidths, and auditory integration times), discuss masking release processes of receivers (including comodulation masking release and spatial release from masking) and anti-masking strategies of signalers (e.g. Lombard effect), and set a research framework for improved assessment of potential masking in marine mammals.

From 2011 to 2013, we conducted a full sanitary survey of pollution sources in proximity to a designated shellfish growing area in Korea, and their impact on the sea area therein. From this area, 836 seawater samples and 93 oyster samples were examined to evaluate their bacteriological quality. There were 483 potential pollution sources in the drainage area of the Jaranman-Saryangdo area, including 38 sources discharging water. It demonstrates that while many pollution sources have been identified, no significant impact occurred within the designated shellfish growing area. Variations in fecal coliform (FC) levels in seawater were closely related to rainfall. The FC levels of seawater and oysters from the designated area met the regulation limits set by various countries. Our study indicates that the oysters produced in this area are apparently safe for raw consumption based on their bacterial quality.

The present study evaluates the PCB-dehalorespiring capabilities and dynamics of indigenous Dehalococcoides mccartyi population in a PCB contaminated marine sediment. Specialized PCB-dechlorinase genes pcbA1, pcbA4 and pcbA5 previously characterized in pure cultures of D. mccartyi, were here found for the first time in environmental samples. Reductive dechlorination was stimulated by spiking Aroclor1254 to the sediment and by imposing strictly anaerobic conditions both with and without bioaugmentation with a Dehalococcoides mccartyi enrichment culture. In line with the contaminant dechlorination kinetics, Dehalococcoides population increased during the entire incubation period showing growth yields of 4.94E+07 Dehalococcoides per μmolCl−1 and 7.30E+05 Dehalococcoides per μmolCl−1 in the marine sediment with and without bioaugmentation respectively. The pcbA4 and pcbA5 dechlorinase genes, and to a lesser extent pcbA1 gene, were enriched during the anaerobic incubation suggesting their role in Aroclor1254 dechlorination under salinity conditions.

Qualitative inferences and sparse bay-wide measurements suggest that shoreline erosion increased after the 2010 BP Deepwater Horizon (DWH) disaster, but quantifying the impacts has been elusive at the landscape scale. We quantified the shoreline erosion of 46 islands for before and after the DWH oil spill to determine how much shoreline was lost, if the losses were temporary, and if recovery/restoration occurred. The erosion rates at the oiled islands increased to 275% in the first six months after the oiling, were 200% of that of the unoiled islands for the first 2.5years after the oiling, and twelve times the average land loss in the deltaic plain of 0.4%y−1 from 1988 to 2011. These results support the hypothesis that oiling compromised the belowground biomass of the emergent vegetation. The islands are, in effect, sentinels of marsh stability already in decline before the oil spill.

Nitrogen (N) supply by atmospheric deposition, wastewater, and fertilizers controls estuarine eutrophication. In New England, atmospheric N loads recently decreased by 50% and land-derived contributions rose about 80%, owing to national-scale emission controls and local urban development. The decrease in atmospheric deposition was large enough to balance increases in land-derived N loads, so total N loads to Waquoit Bay estuaries in Cape Cod did not change significantly between 1990 and 2014. Unchanged N regimes were corroborated by finding no differences in estuarine nutrient concentrations and macrophyte biomass between pre-2005 and in 2015. Coastal zones, subject to reasonably rapid changes in global and local driver variables, will require that assessment and management of eutrophication include adaptive strategies that capture effects of changing baselines. Management initiatives will be constrained by spatial scale of driver variables: local efforts may address wastewater and fertilizer N sources, but atmospheric sources require national or international attention.

Resident mussels are effective indicators of ecosystem health and have been utilized in national assessment and monitoring studies for over two decades. Mussels were chosen because contaminant concentrations in their tissues respond to changes in ambient environmental levels, accumulation occurs with little metabolic transformation and a substantial amount of historic data were available. Mussels were collected from 10 previously studied locations approximately a year after Hurricane Sandy. Regionally, concentrations of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) decreased significantly, while concentrations of organochlorine pesticides (OCPs) remained unchanged, and polybrominated diphenyl ethers (PBDEs) increased compared to historic concentrations. Although concentrations of PCBs, OCPs and PAHs were at or near record low concentrations, long-term trends did not change after Hurricane Sandy. To effectively measure storm-induced impacts it is necessary to understand the factors influencing changes in mussel body burdens and have a long-term monitoring network and an ability to mobilize post event.

The accumulation of litter in marine and coastal environments is a major threat to marine life. Data on marine litter in the gastrointestinal tract of stranded loggerhead turtles, Caretta caretta, found along the Portuguese continental coast was presented. Out of the 95 analysed loggerheads, litter was present in 56 individuals (59.0%) and most had less than 10 litter items (76.8%) and less than 5g (dm) (96.8%). Plastic was the main litter category (frequency of occurrence=56.8%), while sheet (45.3%) was the most relevant plastic sub-category. There was no influence of loggerhead stranding season, cause of stranding or size on the amount of litter ingested (mean number and dry mass of litter items per turtle). The high ingested litter occurrence frequency in this study supports the use of the loggerhead turtle as a suitable tool to monitor marine litter trends, as required by the European Marine Strategy Framework Directive.

This paper looks into the causal association between economic growth, CO2 emission, trade volume, and human development indicator for Brazil, Russia, India, and China (BRIC countries) during 1980–2013. Following a generalized method of moments (GMM) technique, we have found out that bidirectional causality exists between CO2 emissions and economic growth. Feedback hypothesis is supported between CO2 emissions and human development, trade volume and human development, economic growth, and human development, and CO2 emissions and trade volume. Apart from finding out the unidirectional association from trade volume to economic growth, this study also validated the existence of Environmental Kuznets curve. Empirical findings of the study substantiate that the policymakers of the BRIC nations must focus on the green energy initiatives, either by in-house development or by technology transfer. This movement will allow them to control the ambient air pollution prevalent in these nations.

The Laje de Santos Marine State Park (LSMSP) and Xixová-Japuí State Park (XJSP) are two protected areas (PA), close to the Santos Bay in the south Brazilian coast. The region encompasses both important biodiversity and anthropogenic activities. This study aims to serve as a first reference survey of the underwater soundscape of these PAs. Additionally it evaluates the presence of the anthropogenic and biological sound in these areas. One month of continuous recorded underwater sound, at selected locations in XJSP and LSMSP, is used in this study. The data were characterized by its spectral content and by the temporal evolution of Sound Pressure Levels (SPL). Both locations showed sound events with daily periodicities, mainly related with boats and fish chorus.