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Identification of cyanobacteria and microalgae in aerosols of various sizes in the air over the Southern Baltic Sea Full text
2017
Lewandowska, Anita Urszula | Śliwińska-Wilczewska, Sylwia | Woźniczka, Dominika
Bioaerosols were collected between April and November 2015 on land (Gdynia) and at sea (Southwestern Baltic), using six-step microbiological pollutant sampler. It was determined that picoplanktonic cyanobacteria of the genus Synechococcus, Synechocystis, Aphanocapsa, Aphanothece, Microcystis, Merismopedia, Woronichinia and Cyanodictyon were the most commonly found in aerosols both over land and at sea. Chlorophyta were also numerous (Chlorella vulgaris, Stichococcus bacillaris), as were Bacillariophyta and Ochrophyta (Phaeodactylum sp., Navicula cf. perminuta and Nannochloropsis cf. gaditana). As primary production and phytoplankton concentration in sea water grew, so did the diversity of the microorganisms identified in bioaerosols. Over the sea cyanobacteria and microalgae occurred more often in large aerosols (>3.3μm). Over land they were mainly the components of smaller particles. In respirable particles species both capable of producing harmful secondary metabolites and potentially toxic ones were identified. We assume that bioaerosols pose the actual threat to human health in Baltic Sea region.
Show more [+] Less [-]Environmental drivers of sheltering behaviour in large reef fishes Full text
2017
Kerry, James T. | Bellwood, David R.
Studies of shelter use can provide key insights into the ecology, and structural needs of mobile organisms. Using videos, we examined the usage of tabular corals by large reef fishes, over a 10week period, compared to multiple environmental drivers: visibility, tide (and depth), irradiance, wind speed (as a proxy for wave energy) and water temperature. We found that two of these predictor variables (visibility and wind speed) had a significant effect and together accounted for almost half of the variation in tabular coral usage by fishes. Increases in both variables correlated with increased shelter use. To date use of shelters by fishes has primarily been attributed to UV avoidance. Our results support this notion as more turbid conditions (reduced visibility) have an attenuating effect on UV irradiance. Additionally, tabular corals may reduce the energetic costs of increased wave energy by reducing incidental water velocity beneath the structure.
Show more [+] Less [-]Commercially important species associated with horse mussel (Modiolus modiolus) biogenic reefs: A priority habitat for nature conservation and fisheries benefits Full text
2017
Kent, Flora E.A. | Mair, J. M. (James M.) | Newton, Jason | Lindenbaum, Charles | Porter, Joanne S. | Sanderson, William G.
Horse mussel reefs (Modiolus modiolus) are biodiversity hotspots afforded protection by Marine Protected Areas (MPAs) in the NE Atlantic. In this study, horse mussel reefs, cobble habitats and sandy habitats were assessed using underwater visual census and drop-down video techniques in three UK regions. Megafauna were enumerated, differences in community composition and individual species abundances were analysed. Samples of conspicuous megafauna were also collected from horse mussel reefs in Orkney for stable isotope analysis.Communities of conspicuous megafauna were different between horse mussel habitats and other habitats throughout their range. Three commercially important species: whelks (Buccinum undatum), queen scallops (Aequipecten opercularis) and spider crabs (Maja brachydactyla) were significantly more abundant (by as much as 20 times) on horse mussel reefs than elsewhere. Isotopic analysis provided insights into their trophic relationship with the horse mussel reef. Protection of M. modiolus habitat can achieve biodiversity conservation objectives whilst benefiting fisheries also.
Show more [+] Less [-]Multi-criteria decision-making on assessment of proposed tidal barrage schemes in terms of environmental impacts Full text
2017
Wu, Yunna | Xu, Chuanbo | Ke, Yiming | Chen, Kaifeng | Xu, Hu
For tidal range power plants to be sustainable, the environmental impacts caused by the implement of various tidal barrage schemes must be assessed before construction. However, several problems exist in the current researches: firstly, evaluation criteria of the tidal barrage schemes environmental impact assessment (EIA) are not adequate; secondly, uncertainty of criteria information fails to be processed properly; thirdly, correlation among criteria is unreasonably measured. Hence the contributions of this paper are as follows: firstly, an evaluation criteria system is established from three dimensions of hydrodynamic, biological and morphological aspects. Secondly, cloud model is applied to describe the uncertainty of criteria information. Thirdly, Choquet integral with respect to λ-fuzzy measure is introduced to measure the correlation among criteria. On the above bases, a multi-criteria decision-making decision framework for tidal barrage scheme EIA is established to select the optimal scheme. Finally, a case study demonstrates the effectiveness of the proposed framework.
Show more [+] Less [-]Uncovering hidden heterogeneity: Geo-statistical models illuminate the fine scale effects of boating infrastructure on sediment characteristics and contaminants Full text
2017
Hedge, L.H. | Dafforn, K.A. | Simpson, S.L. | Johnston, E.L.
Infrastructure associated with coastal communities is likely to not only directly displace natural systems, but also leave environmental footprints' that stretch over multiple scales. Some coastal infrastructure will, there- fore, generate a hidden layer of habitat heterogeneity in sediment systems that is not immediately observable in classical impact assessment frameworks. We examine the hidden heterogeneity associated with one of the most ubiquitous coastal modifications; dense swing moorings fields. Using a model based geo-statistical framework we highlight the variation in sedimentology throughout mooring fields and reference locations. Moorings were correlated with patches of sediment with larger particle sizes, and associated metal(loid) concentrations in these patches were depressed. Our work highlights two important ideas i) mooring fields create a mosaic of habitat in which contamination decreases and grain sizes increase close to moorings, and ii) model- based frameworks provide an information rich, easy-to-interpret way to communicate complex analyses to stakeholders.
Show more [+] Less [-]A novel approach for monitoring vertical profiles of boundary-layer pollutants: Utilizing routine news helicopter flights Full text
2017
Crosman, Erik T. | Jacques, Alexander A. | Horel, John D.
Air quality varies greatly in space and time across urban locales. However, criteria pollutants are typically monitored routinely at a relatively small number of surface sites within each metropolitan area, and routine vertical profiles of pollution are typically unavailable. We illustrate that a news helicopter provides an effective sensor platform to provide spatiotemporal analyses and vertical profiles of pollutant concentrations. We are unaware of any other air quality study that has utilized routine helicopter flights, despite the ubiquity of helicopters in urban environments across the world. Particulate and ozone concentration profiles have been collected since 2015 from sensors installed on a news helicopter that travels primarily over the metropolitan areas of northern Utah. The air quality data are retrieved in real time, archived, combined with surface-based observations, and disseminated in terms of time series and maps on a website for research, forecasting, and public awareness. Large vertical variations in particulate pollution concentrations were observed during the 2015–2016 winter associated with meteorological cold-air pool episodes. During the 2015 and 2016 summer seasons, ozone concentrations frequently exhibited complex spatial and temporal variations arising from many interrelated factors, including local terrain-forced circulations, lake breezes, and distant wildfires.
Show more [+] Less [-]Effects of sediment contamination on physiological and biochemical responses of the polychaete Diopatra neapolitana, an exploited natural resource Full text
2017
Pires, Adília | Velez, Cátia | Figueira, Etelvina | Soares, Amadeu M.V.M. | Freitas, Rosa
The present study reports metal and arsenic contamination in sediments, as well as element accumulation and partitioning in the polychaete Diopatra neapolitana in the Ria de Aveiro lagoon (Portugal). The polychaetes biochemical performance and tissue regenerative capacity were also evaluated. The concentration of elements in sediments showed an increase of contamination among areas (areas A–G), but higher bioaccumulation was observed in organisms from a less contaminated area (area C, BAF>1). This study evidenced that individuals with higher elements bioaccumulation presented higher LPO and lower GSH/GSSG and also exhibited lower capacity for body regeneration. Polychaetes biotransformation capacity as well as antioxidant defense mechanisms were not sufficiently efficient to withstand the excess of ROS leading to increased LPO when organisms presented higher bioaccumulation levels. Additionally, an increase of methalotionines was also observed in individuals with higher bioaccumulation of metals and As, suggesting an induction of detoxification processes.
Show more [+] Less [-]Development of an integrated indicator system to assess the impacts of reclamation engineering on a river estuary Full text
2017
Xu, Yan | Cai, Yanpeng | Sun, Tao | Yin, Xin'An | Tan, Qian
An integrated indicator system was developed for determining synthetic environmental responses under multiple types of coastal reclamation engineering in the Yellow River estuary, China. Four types of coastal engineering works were analyzed, namely port construction, petroleum exploitation, fishery and aquaculture, and seawall defense. In addition, two areas with limited human disturbances were considered for comparison. From the weights of the response value for each indicator, port construction was determined to be the primary impact contributor among the four engineering works studies. Specifically, hydrodynamic conditions, ecological status, economic costs, and engineering intensity were on average 72.78%, 65.03%, 75.03%, and 66.35% higher than those of other engineering types. Furthermore, fishery and aquaculture impact on water quality was 42.51% higher than that of other engineering types, whereas seawall defense impact on landscape variation was 51.75% higher than that of other engineering types. The proposed indicator system may provide effective coastal management in future.
Show more [+] Less [-]Modelling study of the atmospheric composition over Cyprus Full text
2017
Kushta, Jonilda | Georgiou, Georgios K. | Proestos, Yiannis | Christoudias, Theodoros | Lelieveld, Jos
In this study the online meteorological and chemical transport model “Weather Research and Forecasting coupled with Chemistry” (WRF/Chem) is implemented over Cyprus and evaluated against ground-based air quality and meteorological observations. Hourly O3 concentrations are strongly overestimated and a reduction in the lateral boundaries of ozone by 30% improved model agreement with observations. Utilization of grid spacing closer to the resolution of the emission data leads to an improvement in the simulation of air pollutants, while further reduction of the grid spacing mostly impacts the model performance related to meteorological parameters. The method of speciation of volatile organic compounds can also affect model results. Reduction of NOx emissions can reduce fine particulate (PM2.5) levels relatively effectively due to the important role of nitrate over Cyprus. The present case study indicates that the performance of the WRF/Chem model is reasonable for air quality and meteorological variables over Cyprus when boundary conditions are cautiously adjusted or improved, while there is a need to pursue a high-resolution local emission inventory.
Show more [+] Less [-]Spatial and temporal distribution of pesticides and PCBs in the atmosphere using XAD-resin based passive samplers: A case study in the Quequén Grande River watershed, Argentina Full text
2017
Silva-Barni, M.F. | Gonzalez, M. | Wania, F. | Lei, Y.D. | Miglioranza, K.S.B.
XAD-resin based passive air samplers were deployed at 10 sites in the Quequén Grande River watershed in Argentina during three periods to evaluate the spatial and temporal variations of pesticides and PCBs in the atmosphere. Endosulfan and chlorpyrifos were the most prevalent pesticide because of their continued usage in Argentina, while DDTs, HCHs, chlordanes, dieldrin and heptachlors registered lower levels, reflecting their use in the past. Atmospheric endosulfan levels were 1–2 orders of magnitude higher during the application period (application: 800–12,000 pg/m3, pre- and post-application: <2–350 pg/m3), suggesting that its use in the area continued even after a ban came into effect. The remaining organochlorine pesticides also reached higher concentrations during this period, which is more likely attributable to temperature controlled air-surface exchange than current applications. The highest concentrations of chlorpyrifos were recorded during the application period, in particular at agricultural sites, where its use is wide-spread on soybean fields. The fungicide chlorothalonil was found predominantly at urban sites and in proximity to Quequén harbor, suggesting that its use might be domestic and as a biocide in antifouling paints. A different temporal pattern was observed for the herbicide trifluralin, suggesting its use in the early stages of the wheat-growing season during winter. Limited spatial variations in PCBs levels indicate a diffuse contamination source in the study area, while their relatively high correlation with temperature suggests re-volatilization from local sources. Relative enrichment of lighter PCBs congeners could be attributed to re-evaporation from secondary sources as well as atmospheric transport from urban sites.
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