3 resultados para Organics
em Plymouth Marine Science Electronic Archive (PlyMSEA)
Resumo:
The UK and EU have recently committed to an ecosystem-based approach to the management of our marine environment. In line with the requirements of the Habitats regulations, all consents likely to significantly affect Special Areas of Conservation (SACs) and Special Protection Areas (SPAs) are to be reviewed. As part of this process, 'site characterisation' is seen as an important first step towards the improved management of designated sites. This characterisation series, undertaken by the Marine Biological Association of the United Kingdom and funded by the Environment Agency and English Nature, sets out to determine the current status of designated marine sites in South West England, and how vulnerable (or robust) they are to contaminants (metals, organics, nutrients) and other anthropogenic pressures. Using published information and unpublished data-sets from regulatory agencies, conservation bodies and research institutes (particularly those of the PMPS*), evidence is compiled on the links between potentially harmful 'activities', environmental quality, and resultant biological consequences. This includes an evaluation of long-term change. The focus is the effect of water and sediment quality on the key interest features of European Marine sites in the South West of England, namely: - Fal and Helford cSAC (MBA Occasional Publication 8) - Plymouth Sound and Estuaries cSAC/ SPA (MBA Occasional Publication 9) - Exe Estuary SPA (MBA Occasional Publication 10) - Chesil and the Fleet cSAC/ SPA (MBA Occasional Publication 11) - Poole Harbour SPA (MBA Occasional Publication 12) - Severn Estuary pSAC/SPA (MBA Occasional Publication 13) Detailed analysis for each of these sites is provided individually. The summary report contains an overview of physical properties, uses and vulnerability for each of these sites, together with brief comparisons of pollution sources, chemical exposure (via sediment and water) and evidence of biological impact (from bioaccumulation to community-level response). Limitations of the data, and gaps in our understanding of these systems are highlighted and suggestions are put forward as to where future research and surveillance is most needed. Hopefully this may assist the statutory authorities in targeting future monitoring and remedial activities. * PMSP: Plymouth Marine Sciences Partnership, comprising the Marine Biological Association (MBA), University of Plymouth (UoP), the Sir Alister Hardy Foundation for Ocean Science, and Plymouth Marine Laboratories (PML)
Resumo:
The production rates of a range of low molecular weight halogenated organics have been determined in cultures of five temperate species of macroalgae collected from the north coast of Norfolk, England. Compounds studied included CH3Br, the chlorinated organics CH3Cl, CH2Cl2 and CHCl3, and the iodinated organics CH3I, C2H5I, and CH2ClI. Measurements of a wider range of halocarbon concentrations in an isolated rockpool and in air over the seaweed bed were also conducted to evaluate the local impact of the seaweeds on halocarbon concentrations in the natural environment. Estimates for the global emissions of some of the key halogenated compounds from macroalgae have been derived. In general macrophytes appear not to be globally significant producers of the particular halocarbons studied. In coastal regions, however, the impact on local atmospheric composition and chemistry could be greater.
Resumo:
We present air-sea fluxes of oxygenated volatile organics compounds (OVOCs) quantified by eddy covariance (EC) during the Atlantic Meridional Transect cruise in 2012. Measurements of acetone, acetaldehyde, and methanol in air as well as in water were made in several different oceanic provinces and over a wide range of wind speeds (1-18 m s(-1)). The ocean appears to be a net sink for acetone in the higher latitudes of the North Atlantic but a source in the subtropics. In the South Atlantic, seawater acetone was near saturation relative to the atmosphere, resulting in essentially zero net flux. For acetaldehyde, the two-layer model predicts a small oceanic emission, which was not well resolved by the EC method. Chemical enhancement of air-sea acetaldehyde exchange due to aqueous hydration appears to be minor. The deposition velocity of methanol correlates linearly with the transfer velocity of sensible heat, confirming predominant airside control. We examine the relationships between the OVOC concentrations in air as well as in water, and quantify the gross emission and deposition fluxes of these gases.