117 research outputs found

    Bigger juveniles and smaller adults : changes in fish size correlate with warming seas

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    Funding Information Niger Delta Development Commission (NDDC) H2020 Societal Challenges. Grant Number: 677039 ACKNOWLEDGEMENTS We thank Marine Scotland Science for their help during data compilation, notably for the West of Scotland. We are also grateful to Tara Marshall and John Morrongiello for their suggestions during early stages of data analyses. Funding for I.E.I. PhD comes from the Niger Delta Development Commission (NDDC), which is gratefully acknowledged. P.G.F., A.R.B. and A.P. were supported by the Horizon 2020 European research project ClimeFish (grant No. 677039).Peer reviewedPostprin

    Impact of ocean warming on sustainable fisheries management informs the Ecosystem Approach to Fisheries

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    Acknowledgements Serpetti N., Heymans J.J., and Burrows M.T. were funded by the Natural Environment Research Council and Department for Environment, Food and Rural Affairs under the Marine Ecosystems Research Programme (MERP) (grant No. NE/L003279/1). Baudron A. and Fernandes, P.G. were founded by Horizon 2020 European research projects MareFrame (grant No. 613571) and ClimeFish (grant No. 677039). Payne, B.L. was founded by the Natural Environment Research Council and Department for Environment under the ‘Velocity of Climate Change’ (grant No. NE/J024082/1).Peer reviewedPublisher PD

    FIS workshop on Global synthesis of climate impacts on fish distribution and growth and implications for Scottish fisheries : FIS028

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    All workshop attendees and remote participants (identified in Table 1) are thanked for their contributions to presentations, discussion and this report. A. Audzijonyte, R. Allman, B. Bogstad, C. Champion, T. Essington, M. Haltuch, A. Haynie, T. Helser, E. Hjörleifsson, J. Morrongiello, M. Peck, G. Pecl, J. Pinnegar, M. Pinsky, C. Stawitz, B. Townhill, J. Thorson, and P.D. van Denderen contributed text to this report. George R. West is thanked for his participation in the public event. Jens Rasmussen assisted in the development of recommendations for future research. The assistance of Mindfully Wired Communications (Harriet Yates and Ginny Russell) is gratefully acknowledged.Publisher PD

    Investigation of thermo-hydro-geochemical processes in a standing column well intersected by a fracture

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    Local thermal and chemical conditions may favor minerals' scaling which can cause undesirable operational problems to standing column well systems. Precipitation may reduce heat exchange in the well and the heat exchanger and increase pressure drops in the systems components, as well as the drawdown in the well. In this paper, a coupled thermo-hydro-geochemical model simulating the operation of a standing column well is used to illustrate the link between the temperature and the reaction rate of calcite. The results demonstrate that bleeding only 10% of the pumped water allows to get rid of calcium ions in solution in the well and reduces substantially the precipitated calcite mass. Our simulations clearly indicate that groundwater flow induced by the bleed mainly occurs in the fracture since significant chemical variations are observed downstream of the fracture. We expect that the findings presented in the paper will help demystify the complex thermo-hydro-geochemical behaviour of standing column wells installed in sedimentary rocks

    Can the Common Fisheries Policy achieve Good Environmental Status in exploited ecosystems : the west of Scotland demersal fisheries example

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    Alan R. Baudron, Niall G. Fallon and Paul G. Fernandes were funded by the Horizon 2020 European research project MareFrame (grant No. 613571). Natalia Serpetti and Johanna J. Heymans were funded by the Natural Environment Research Council and Department for Environment, Food and Rural Affairs under the Marine Ecosystems Research Programme (MERP) (grant No. NE/L003279/1). We thank two anonymous reviewers for their insightful comments.Peer reviewedPostprintPostprintPostprintPostprin

    Participatory planning and decision support for ecosystem based fisheries management of the west coast of Scotland

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    Mixed fisheries and the marine ecosystems that sustain them are complex entities and involve multiple and potentially conflicting management objectives and stakeholder interests. The presence of multiple trade-offs complicates the identification of strategies that satisfy various policy requirements while being acceptable to affected stakeholder groups. This creates a demand for tools and processes that support learning, cooperation and planning. We report on the application of decision support methodology used in combination with a co-creation approach to scenario based planning for the demersal fisheries of the West coast of Scotland. These fisheries face significant challenges, such as the depletion of key stocks and increased predation by seals. In collaboration with stakeholders we identified generic management alternatives and indicators to evaluate their performance in a structured evaluation using Multi Criteria Analysis. We identify the potential and limitations of this approach and suggest how it can contribute to Ecosystem Based Fisheries Management (EBFM). This approach does not provide tactical management advice, but stimulates learning and creates an opportunity for stakeholders to search for strategic and policy relevant solutions in an EBFM context.Peer reviewe

    Evaluating Bank-Filtration Occurrence in the Province of Quebec (Canada) with a GIS Approach

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    Due to the abundance of surface water in the province of Quebec, Canada, it is suspected that many groundwater wells are pumping a mixture of groundwater and surface water via induced bank filtration (IBF). The regulatory framework in Quebec provides comprehensive guidelines for the development and monitoring of surface water and groundwater drinking water production systems. However, the regulations do not specifically address hybrid groundwater-surface water production systems such as IBF sites. More knowledge on the use of IBF in the province is needed to adjust the regulations with respect to the particularities of these systems. In order to provide a first evaluation of municipal wells potentially using IBF and the corresponding population served by these wells, a Geographic Information Science framework (GISc) was used to implement an IBF spatial database and calculate the distance from each well to the nearest surface water body. GISc is based on open source GIS programs and openly available data, to facilitate the reproducibility of the work. From this provincial scale approach, we show that nearly one million people are supplied by groundwater from municipal wells located <500 m from a surface water body, and half a million have a significant probability to be supplied by IBF wells. A more focused look at the watershed scale distribution of wells allows us to improve our interpretations by considering the aquifer type and other regional factors. This approach reveals strong spatial variability in the distribution of wells in proximity to surface water. Of the three selected regions, one has a high potential for IBF (Laurentides), one requires additional information do draw precise conclusions (Nicolet), and the third region (Vaudreuil-Soulanges) is unlikely to have widespread use of IBF. With this study, we demonstrate that extensive use of IBF is likely and that there is a need for improved understanding and management of these sites in order to properly protect the drinking water supply

    A portrait of wellbore leakage in northeastern British Columbia, Canada

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    Oil and gas well leakage is of public concern primarily due to the perceived risks of aquifer contamination and greenhouse gas (GHG) emissions. This study examined well leakage data from the British Columbia Oil and Gas Commission (BC OGC) to identify leakage pathways and initially quantify incident rates of leakage and GHG emissions from leaking wells. Three types of leakage are distinguished: “surface casing vent flow” (SCVF), “outside the surface casing leakage” (OSCL), and “cap leakage” (CL). In British Columbia (BC), the majority of reported incidents involve SCVF of gases, which does not pose a risk of aquifer contamination but does contribute to GHG emissions. Reported liquid leakage of brines and hydrocarbons is rarer. OSCL and CL of gas are more serious problems due to the risk of long-term leakage from abandoned wells; some were reported to be leaking gas several decades after they were permanently abandoned. According to the requirements of provincial regulation, 21,525 have been tested for leakage. In total, 2,329 wells in BC have had reported leakage during the lifetime of the well. This represents 10.8% of all wells in the assumed test population. However, it seems likely that wells drilled and/or abandoned before 2010 have unreported leakage. In BC, the total GHG emission from gas SCVF is estimated to reach about 75,000 t/y based on the existing inventory calculation; however, this number is likely higher due to underreporting

    Investigating Multilayer Aquifer Dynamics by Combining Geochemistry, Isotopes and Hydrogeological Context Analysis

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    ABSTRACT: Geochemical tracers have the potential to provide valuable insights for constructing conceptual models of groundwater flow, especially in complex geological contexts. Nevertheless, the reliability of tracer interpretation hinges on its integration into a robust geological framework. In our research, we concentrated on delineating the groundwater flow dynamics in the Innisfil Creek watershed, located in Ontario, Canada. We amalgamated extensive hydrogeological data derived from a comprehensive 3D geological model with the analysis of 61 groundwater samples, encompassing major ions, stable water isotopes, tritium, and radiocarbon. By seamlessly incorporating regional physiographic characteristics, flow pathways, and confinement attributes, we bolstered the efficiency of these tracers, resulting in several notable findings. Firstly, we identified prominent recharge and discharge zones within the watershed. Secondly, we observed the coexistence of relatively shallow and fast-flowing paths with deeper, slower-flowing channels, responsible for transporting groundwater from ancient glacial events. Thirdly, we determined that cation exchange stands as the predominant mechanism governing the geochemical evolution of contemporary water as it migrates toward confined aquifers situated at the base of the Quaternary sequence. Fourthly, we provided evidence of the mixing of modern, low-mineralized water originating from unconfined aquifer units with deep, highly mineralized water within soil–bedrock interface aquifers. These findings not only contribute significantly to the development a conceptual flow model for the sustainable management of groundwater in the Innisfil watershed, but also offer practical insights that hold relevance for analogous geological complexities encountered in other regions

    Recharge, groundwater flow pattern and contamination processes in an arid volcanic area: Insights from isotopic and geochemical tracers (Bara aquifer system, Republic of Djibouti)

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    Fractured volcanic aquifers are the main water resources in the arid climate of the Republic of Djibouti. Nonetheless, these strategic reservoirs are overexploited and their comprehensive understanding is therefore a pre-requisite for a sustainable use. A geochemical and isotopic survey, including major ion chemistry, 2H, 18O, 13C, 3H, 87Sr/86Sr, 15N was performed and combined with existing 14C data to study recharge, contamination processes and groundwater flow patterns inside and between the compartments of a complex aquifer system composed by basaltic rocks and by alluvium located in Petit Bara, Grand Bara, and Mouloud areas (Southwest of Djibouti). A main feature was the common trend from a fresh Na-Cl-HCO3 water type (alluvium groundwaters) to an intermediate water type (alluvium and basalt groundwaters) and finally to a Na-Cl-SO4 water type (most mineralized basalt groundwater). Elementary and isotopic nitrate evidenced and located anthropogenic and geogenic origins of nitrate. Alluvium groundwaters had δ2H and δ18O signature of modern precipitation while basalt groundwaters were significantly depleted and enriched in δ13C due to water-rock interactions. Modern radiocarbon and tritium were evidenced in the alluvium groundwaters, while recalculated radiocarbon ages located recharge of the basalt groundwaters in the early to mid-Holocene. These features revealed a common evolutionary pattern, with a recharge from wadi-rivers to the alluvium and a downward circulation to the basalt through major faults, combined with a mixing with a more geochemically evolved groundwater. Accordingly, highly saline groundwater at the outlet of the Petit Bara plain was found to be diluted by modern recharge in the alluvium. Two major basaltic aquifer compartments were found to be connected (Grand Bara and Mouloud), revealing a global northeastward flowpath below the endorheic Grand Bara plain
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