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Lloyd CEM, Johnes PJ, Pemberton JA, Yates CA, Jones D, Evershed RP. Sampling, storage and laboratory approaches for dissolved organic matter characterisation in freshwaters: Moving from nutrient fraction to molecular-scale characterisation. Sci Total Environ 2022; 827:154105. [PMID: 35219656 DOI: 10.1016/j.scitotenv.2022.154105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/18/2022] [Accepted: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Recent research has highlighted the importance of dissolved organic matter (DOM) for ecosystem function and because of this paradigm shift, it has become crucial to not only quantify its contribution to river nutrient loads but also to characterise its composition. There has been a significant research effort utilising optical methods, such as fluorescence and UV-Vis spectrophotometry, in order to start exploring DOM character. However, these methods still lack the granularity to understand the chemical composition at the molecular level, which is vital to properly understanding its functional role in freshwater ecosystems. As a direct result, there has been a shift towards including molecular-scale analyses to investigate the in-stream processing of the material. Alongside this, recent methodological advancements, particularly in mass spectrometry are opening new opportunities for probing one of the most complex environmental mixtures. However, in order to fully exploit these opportunities, it is key that the way that samples are collected, processed and stored is considered carefully such that sample integrity is maintained. There are additional challenges when collecting water samples for analysis at molecular scale, for example the ultra-low concentrations of individual compounds within DOM means that the samples are sensitive to contamination. This paper discusses current sample collection, processing and storage protocols for this C, N and P quantification and characterisation in freshwaters, and proposes a new standardised protocol suitable for both nutrient fraction quantification and molecular scale analyses, based on method development and testing undertaken in our UK Natural Environment Research Council large grant programme, characterising the nature, origins and ecological significance of Dissolved Organic Matter IN freshwater Ecosystems (DOMAINE).
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Affiliation(s)
- C E M Lloyd
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK.
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK
| | - J A Pemberton
- Wessex Water, Operations Centre, Claverton Down, Bath BA2 7WW, UK
| | - C A Yates
- School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK; Atkins, The Hub, 500 Park Avenue, Aztec West, Bristol BS32 4RZ, UK
| | - D Jones
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; SoilsWest, Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA 6105, Australia
| | - R P Evershed
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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2
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Mackay EB, Feuchtmayr H, De Ville MM, Thackeray SJ, Callaghan N, Marshall M, Rhodes G, Yates CA, Johnes PJ, Maberly SC. Dissolved organic nutrient uptake by riverine phytoplankton varies along a gradient of nutrient enrichment. Sci Total Environ 2020; 722:137837. [PMID: 32197159 DOI: 10.1016/j.scitotenv.2020.137837] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/04/2020] [Accepted: 03/08/2020] [Indexed: 05/27/2023]
Abstract
The concentration of dissolved organic matter (DOM) in freshwaters is increasing in large areas of the world. In addition to carbon, DOM contains nitrogen and phosphorus and there is growing concern that these organic nutrients may be bioavailable and contribute to eutrophication. However, relatively few studies have assessed the potential for dissolved organic nitrogen (DON) or dissolved organic phosphorus (DOP) compounds to be bioavailable to natural river phytoplankton communities at different locations or times. Temporal and spatial variations in uptake, relative to environmental characteristics were examined at six riverine sites in two contrasting catchments in the UK. This study also examined how the uptake by riverine phytoplankton of four DON and four DOP compounds commonly found in rivers, varied with concentration. Total nitrogen (TN) and phosphorus (TP) concentrations, the proportion of inorganic nutrient species, and nutrient limitation varied temporally and spatially, as did the potential for DON and DOP uptake. All eight of the DOM compounds tested were bioavailable, but to different extents. Organic nutrient use depended on the concentration of the organic compound supplied, with simple compounds (urea and glucose-6-phosphate) supporting algal growth even at very low concentrations. DON use was negatively correlated with the TN and ammonia concentration and DOP use was negatively correlated with soluble reactive phosphorus (SRP) and dissolved organic carbon (DOC) concentration. The evidence indicates that DOM in rivers has been overlooked as a potential source of nutrients to phytoplankton and therefore as an agent of eutrophication.
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Affiliation(s)
- E B Mackay
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK.
| | - H Feuchtmayr
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK
| | - M M De Ville
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK
| | - S J Thackeray
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK
| | - N Callaghan
- UK Centre for Ecology & Hydrology, Environment Centre Wales, Bangor, Gwynedd LL57 2UW, UK
| | - M Marshall
- School of Environment, Natural Resources and Geography, Bangor University, Environment Centre Wales, Bangor, Gwynedd LL57 2UW, UK
| | - G Rhodes
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK
| | - C A Yates
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - S C Maberly
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP, UK
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3
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Brailsford FL, Glanville HC, Golyshin PN, Marshall MR, Lloyd CE, Johnes PJ, Jones DL. Nutrient enrichment induces a shift in dissolved organic carbon (DOC) metabolism in oligotrophic freshwater sediments. Sci Total Environ 2019; 690:1131-1139. [PMID: 31470476 DOI: 10.1016/j.scitotenv.2019.07.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/02/2019] [Accepted: 07/04/2019] [Indexed: 05/27/2023]
Abstract
Dissolved organic carbon (DOC) turnover in aquatic environments is modulated by the presence of other key macronutrients, including nitrogen (N) and phosphorus (P). The ratio of these nutrients directly affects the rates of microbial growth and nutrient processing in the natural environment. The aim of this study was to investigate how labile DOC metabolism responds to changes in nutrient stoichiometry using 14C tracers in conjunction with untargeted analysis of the primary metabolome in upland peat river sediments. N addition led to an increase in 14C-glucose uptake, indicating that the sediments were likely to be primarily N limited. The mineralisation of glucose to 14CO2 reduced following N addition, indicating that nutrient addition induced shifts in internal carbon (C) partitioning and microbial C use efficiency (CUE). This is directly supported by the metabolomic profile data which identified significant differences in 22 known metabolites (34% of the total) and 30 unknown metabolites (16% of the total) upon the addition of either N or P. 14C-glucose addition increased the production of organic acids known to be involved in mineral P dissolution (e.g. gluconic acid, malic acid). Conversely, when N was not added, the addition of glucose led to the production of the sugar alcohols, mannitol and sorbitol, which are well known microbial C storage compounds. P addition resulted in increased levels of several amino acids (e.g. alanine, glycine) which may reflect greater rates of microbial growth or the P requirement for coenzymes required for amino acid synthesis. We conclude that inorganic nutrient enrichment in addition to labile C inputs has the potential to substantially alter in-stream biogeochemical cycling in oligotrophic freshwaters.
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Affiliation(s)
- F L Brailsford
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; Centre for Environmental Biotechnology, Bangor University, Bangor, Gwynedd LL57 2UW, UK.
| | - H C Glanville
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; School of Geography, Geology and the Environment, Keele University, Staffordshire ST5 5BG, UK
| | - P N Golyshin
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; Centre for Environmental Biotechnology, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - M R Marshall
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - C E Lloyd
- School of Chemistry, University of Bristol, University Road, Bristol BS8 1TS, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - D L Jones
- Environment Centre Wales, Bangor University, Bangor, Gwynedd LL57 2UW, UK; UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia
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Lloyd CEM, Johnes PJ, Freer JE, Carswell AM, Jones JI, Stirling MW, Hodgkinson RA, Richmond C, Collins AL. Determining the sources of nutrient flux to water in headwater catchments: Examining the speciation balance to inform the targeting of mitigation measures. Sci Total Environ 2019; 648:1179-1200. [PMID: 30340264 DOI: 10.1016/j.scitotenv.2018.08.190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
Diffuse water pollution from agriculture (DWPA) is a major environmental concern, with significant adverse impacts on both human and ecosystem health. However, without an appropriate understanding of the multiple factors impacting on water, mitigation measures cannot be targeted. Therefore, this paper addresses this gap in understanding, reporting the hydrochemical monitoring evidence collected from the UK Government's Demonstration Test Catchments (DTC) programme including contrasting chalk and clay/mudstone catchments. We use data collected at daily and sub-daily frequency over multiple sites to address: (1) How does the behaviour of the full range of nitrogen (N) species and phosphorus (P) fractions vary? (2) How do N species and P fractions vary inter- and intra-annually? (3) What do these data indicate about the primary pollution sources? And (4) which diffuse pollution mitigation measures are appropriate in our study landscapes? Key differences in the rates of flux of nutrients were identified, dependent on catchment characteristics. Full N speciation and P fractionation, together with dissolved organic carbon (DOC) enabled identification of the most likely contributing sources in each catchment. Nitrate (NO3-N) was the dominant N fraction in the chalk whereas organic and particulate N comprised the majority of the load in the clay/mudstone catchments. Despite current legislation, orthophosphate (PO4-P) was not found to be the dominant form of P in any of the catchments monitored. The chalk sub-catchments had the largest proportion of inorganic/dissolved organic P (DOP), accompanied by episodic delivery of particulate P (PP). Contrastingly, the clay/mudstone sub-catchments loads were dominated by PP and DOP. Thus, our results show that by monitoring both the inorganic and organic fractions a more complete picture of catchment nutrient fluxes can be determined, and sources of pollution pin-pointed. Ultimately, policy and management to bring nutrient impacts under control will only be successful if a multi-stressor approach is adopted.
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Affiliation(s)
- C E M Lloyd
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK; Cabot Institute, University of Bristol, BS8 1UJ Bristol, UK
| | - J E Freer
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK; Cabot Institute, University of Bristol, BS8 1UJ Bristol, UK
| | - A M Carswell
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
| | - J I Jones
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - M W Stirling
- School of Archaeology, Geography and Environmental Sciences, University of Reading, Reading RG6 6AB, UK
| | - R A Hodgkinson
- Soils, Agriculture and Water, RSK ADAS Ltd, Spring Lodge, 172 Chester Road, Helsby WA6 0AR, UK
| | - C Richmond
- Soils, Agriculture and Water, RSK ADAS Ltd, Spring Lodge, 172 Chester Road, Helsby WA6 0AR, UK
| | - A L Collins
- Sustainable Agriculture Sciences Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
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5
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Brailsford FL, Glanville HC, Marshall MR, Golyshin PN, Johnes PJ, Yates CA, Owen AT, Jones DL. Microbial use of low molecular weight DOM in filtered and unfiltered freshwater: Role of ultra-small microorganisms and implications for water quality monitoring. Sci Total Environ 2017; 598:377-384. [PMID: 28448929 DOI: 10.1016/j.scitotenv.2017.04.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/03/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Dissolved organic matter (DOM) plays a central role in regulating productivity and nutrient cycling in freshwaters. It is therefore vital that we can representatively sample and preserve DOM in freshwaters for subsequent analysis. Here we investigated the effect of filtration, temperature (5 and 25°C) and acidification (HCl) on the persistence of low molecular weight (MW) dissolved organic carbon (DOC), nitrogen (DON) and orthophosphate in oligotrophic and eutrophic freshwater environments. Our results showed the rapid loss of isotopically-labelled glucose and amino acids from both filtered (0.22 and 0.45μm) and unfiltered waters. We ascribe this substrate depletion in filtered samples to the activity of ultra-small (<0.45μm) microorganisms (bacteria and archaea) present in the water. As expected, the rate of C, N and P loss was much greater at higher temperatures and was repressed by the addition of HCl. Based on our results and an evaluation of the protocols used in recently published studies, we conclude that current techniques used to sample water for low MW DOM characterisation are frequently inadequate and lack proper validation. In contrast to the high degree of analytical precision and rigorous statistical analysis of most studies, we argue that insufficient consideration is still given to the presence of ultra-small microorganisms and potential changes that can occur in the low MW fraction of DOM prior to analysis.
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Affiliation(s)
- F L Brailsford
- School of Environment, Natural Resources & Geography, Bangor University, Bangor, Gwynedd LL57 2UW, UK.
| | - H C Glanville
- School of Environment, Natural Resources & Geography, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - M R Marshall
- Centre for Ecology and Hydrology (CEH), Environment Centre Wales, Bangor, Gwynedd LL57 2UW, UK
| | - P N Golyshin
- School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - C A Yates
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - A T Owen
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - D L Jones
- School of Environment, Natural Resources & Geography, Bangor University, Bangor, Gwynedd LL57 2UW, UK
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6
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Collins AL, Zhang YS, Winter M, Inman A, Jones JI, Johnes PJ, Cleasby W, Vrain E, Lovett A, Noble L. Tackling agricultural diffuse pollution: What might uptake of farmer-preferred measures deliver for emissions to water and air? Sci Total Environ 2016; 547:269-281. [PMID: 26789365 DOI: 10.1016/j.scitotenv.2015.12.130] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/24/2015] [Accepted: 12/24/2015] [Indexed: 06/05/2023]
Abstract
Mitigation of agricultural diffuse pollution poses a significant policy challenge across Europe and particularly in the UK. Existing combined regulatory and voluntary approaches applied in the UK continue to fail to deliver the necessary environmental outcomes for a variety of reasons including failure to achieve high adoption rates. It is therefore logical to identify specific on-farm mitigation measures towards which farmers express positive attitudes for higher future uptake rates. Accordingly, a farmer attitudinal survey was undertaken during phase one of the Demonstration Test Catchment programme in England to understand those measures towards which surveyed farmers are most receptive to increasing implementation in the future. A total of 29 on-farm measures were shortlisted by this baseline farm survey. This shortlist comprised many low cost or cost-neutral measures suggesting that costs continue to represent a principal selection criterion for many farmers. The 29 measures were mapped onto relevant major farm types and input, assuming 95% uptake, to a national scale multi-pollutant modelling framework to predict the technically feasible impact on annual agricultural emissions to water and air, relative to business as usual. Simulated median emission reductions, relative to current practise, for water management catchments across England and Wales, were estimated to be in the order sediment (20%)>ammonia (16%)>total phosphorus (15%) ≫ nitrate/methane (11%)>nitrous oxide (7%). The corresponding median annual total cost of the modelled scenario to farmers was £3 ha(-1)yr(-1), with a corresponding range of -£84 ha(-1)yr(-1) (i.e. a net saving) to £33 ha(-1)yr(-1). The results suggest that those mitigation measures which surveyed farmers are most inclined to implement in the future would improve the environmental performance of agriculture in England and Wales at minimum to low cost per hectare.
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Affiliation(s)
- A L Collins
- Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK.
| | - Y S Zhang
- Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
| | - M Winter
- Centre for Rural Policy Research, University of Exeter, Exeter EX4 4SB, UK
| | - A Inman
- Centre for Rural Policy Research, University of Exeter, Exeter EX4 4SB, UK
| | - J I Jones
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - W Cleasby
- Eden Rivers Trust, Newton Rigg College, Newton Rigg, Penrith, Cumbria CA11 0AH, UK
| | - E Vrain
- School of Environmental Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - A Lovett
- School of Environmental Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - L Noble
- Farm Systems and Environment Ltd, Low Road, Wortwell, Norfolk IP20 0HJ, UK
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7
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Lloyd CEM, Freer JE, Johnes PJ, Collins AL. Using hysteresis analysis of high-resolution water quality monitoring data, including uncertainty, to infer controls on nutrient and sediment transfer in catchments. Sci Total Environ 2016; 543:388-404. [PMID: 26599139 DOI: 10.1016/j.scitotenv.2015.11.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/05/2015] [Accepted: 11/05/2015] [Indexed: 05/19/2023]
Abstract
A large proportion of nutrients and sediment is mobilised in catchments during storm events. Therefore understanding a catchment's hydrological behaviour during storms and how this acts to mobilise and transport nutrients and sediment to nearby watercourses is extremely important for effective catchment management. The expansion of available in-situ sensors is allowing a wider range of water quality parameters to be monitored and at higher temporal resolution, meaning that the investigation of hydrochemical behaviours during storms is increasingly feasible. Studying the relationship between discharge and water quality parameters in storm events can provide a valuable research tool to infer the likely source areas and flow pathways contributing to nutrient and sediment transport. Therefore, this paper uses 2 years of high temporal resolution (15/30 min) discharge and water quality (nitrate-N, total phosphorus (TP) and turbidity) data to examine hysteretic behaviour during storm events in two contrasting catchments, in the Hampshire Avon catchment, UK. This paper provides one of the first examples of a study which comprehensively examines storm behaviours for up to 76 storm events and three water quality parameters. It also examines the observational uncertainties using a non-parametric approach. A range of metrics was used, such as loop direction, loop area and a hysteresis index (HI) to characterise and quantify the storm behaviour. With two years of high resolution information it was possible to see how transport mechanisms varied between parameters and through time. This study has also clearly shown the different transport regimes operating between a groundwater dominated chalk catchment versus a surface-water dominated clay catchment. This information, set within an uncertainty framework, means that confidence can be derived that the patterns and relationships thus identified are statistically robust. These insights can thus be used to provide information regarding transport processes and biogeochemical processing within river catchments.
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Affiliation(s)
- C E M Lloyd
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK.
| | - J E Freer
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK
| | - A L Collins
- Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
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Whitehead PG, Jin L, Crossman J, Comber S, Johnes PJ, Daldorph P, Flynn N, Collins AL, Butterfield D, Mistry R, Bardon R, Pope L, Willows R. Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards. Sci Total Environ 2014; 481:157-166. [PMID: 24594744 DOI: 10.1016/j.scitotenv.2014.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 01/30/2014] [Accepted: 02/02/2014] [Indexed: 06/03/2023]
Abstract
The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost.
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Affiliation(s)
- P G Whitehead
- School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK.
| | - L Jin
- Department of Geology, State University of New York College at Cortland, Cortland, NY 13045, USA
| | - J Crossman
- School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK
| | - S Comber
- Department of Environmental Science, Plymouth University, Drakes Circus, Plymouth PL4 8AA, UK
| | - P J Johnes
- School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK and Cabot Institute, University of Bristol, Bristol BS8 1UJ, UK
| | - P Daldorph
- Atkins Limited, Chadwick House, Birchwood, Warrington WA3 6AE, UK
| | - N Flynn
- School of Geography and Environmental Science, University of Reading, RG6 6AB. UK
| | - A L Collins
- Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK
| | - D Butterfield
- School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK
| | - R Mistry
- Atkins Limited, Chadwick House, Birchwood, Warrington WA3 6AE, UK
| | - R Bardon
- Wessex Water, Clevedon Walk, Nailsea, Bristol BS48 1WA, UK
| | - L Pope
- Environment Agency, Thames Regional Office, Kings Meadow House, Kings Meadow Road, Reading, Berkshire RG1 8DQ, UK
| | - R Willows
- Environment Agency, Thames Regional Office, Kings Meadow House, Kings Meadow Road, Reading, Berkshire RG1 8DQ, UK
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9
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Yates CA, Johnes PJ. Nitrogen speciation and phosphorus fractionation dynamics in a lowland Chalk catchment. Sci Total Environ 2013; 444:466-479. [PMID: 23287536 DOI: 10.1016/j.scitotenv.2012.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 06/01/2023]
Abstract
A detailed analysis of temporal and spatial trends in nitrogen (N) speciation and phosphorus (P) fractionation in the Wylye, a lowland Chalk sub-catchment of the Hampshire Avon, UK is presented, identifying the sources contributing to nutrient enrichment, and temporal variability in the fractionation of nutrients in transit from headwaters to lower reaches of the river. Samples were collected weekly from ten monitoring stations with daily sampling at three further sites over one year, and monthly inorganic N and total reactive P (TRP) concentrations at three of the ten weekly monitoring stations over a ten year period are also presented. The data indicate significant daily and seasonal variation in nutrient fractionation in the water column, resulting from plant uptake of dissolved organic and inorganic nutrient fractions in the summer months, increased delivery of both N and P from diffuse sources in the autumn to winter period and during high flow events, and lack of dilution of point source discharges to the Wylye from septic tank, small package Sewage Treatment Works (STW) and urban Waste Water Treatment Works (WwTW) during the summer low flow period. Weekly data show that contributing source areas vary along the river with headwater N and P strongly influenced by diffuse inorganic N and particulate P fluxes, and SRP and organic-rich point source contributions from STW and WwTW having a greater influence in the lower reaches. Long-term data show a decrease in TRP concentrations at all three monitoring stations, with the most pronounced decrease occurring downstream from Warminster WwTW, following the introduction of P stripping at the works in 2001. Inorganic N demonstrates no statistically significant change over the ten year period of record in the rural headwaters, but an increase in the lower reaches downstream from the WwTW which may be due to urban expansion in the lower catchment.
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Affiliation(s)
- C A Yates
- School of Human and Environmental Science, University of Reading, Whiteknights, Reading, RG6 6AB, United Kingdom.
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10
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Vitousek PM, Naylor R, Crews T, David MB, Drinkwater LE, Holland E, Johnes PJ, Katzenberger J, Martinelli LA, Matson PA, Nziguheba G, Ojima D, Palm CA, Robertson GP, Sanchez PA, Townsend AR, Zhang FS. Response—Nutrient Imbalances. Science 2009. [DOI: 10.1126/science.326_665c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- P. M. Vitousek
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - R. Naylor
- Woods Institute for the Environment and Freeman Spogli Institute for International Studies, Stanford University, Stanford, CA 94305, USA
| | - T. Crews
- Environmental Studies, Prescott College, Prescott, AZ 86301, USA
| | - M. B. David
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, IL 61801, USA
| | - L. E. Drinkwater
- Department of Horticulture, Cornell University, Ithaca, NY 14853, USA
| | - E. Holland
- National Center for Atmospheric Research, Boulder, CO 80307, USA
| | - P. J. Johnes
- Aquatic Environments Research Centre, School for Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6AB, UK
| | | | - L. A. Martinelli
- Centro de Energia Nuclear na Agricultura–Universidade São Paulo (CENA-USP), Avenida Centenario 303, 13416-000, Piracicaba, SP, Brazil
| | - P. A. Matson
- School of Earth Sciences, Stanford University, Stanford, CA 94305, USA
| | - G. Nziguheba
- The Earth Institute, Columbia University–Lamont Campus, Palisades, NY 10027, USA
| | - D. Ojima
- The Heinz Center for Science, Economics, and the Environment, Washington, DC 20009, USA
| | - C. A. Palm
- The Earth Institute, Columbia University–Lamont Campus, Palisades, NY 10027, USA
| | - G. P. Robertson
- Department of Crop and Soil Sciences, Michigan State University, Hickory Corners, MI 49060, USA
| | - P. A. Sanchez
- The Earth Institute, Columbia University–Lamont Campus, Palisades, NY 10027, USA
| | - A. R. Townsend
- Department of Ecology and Evolutionary Biology and INSTAAR, University of Colorado, Boulder, CO 80309, USA
| | - F. S. Zhang
- College of Resources and Environmental Science, China Agricultural University, Beijing 100094, China
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Vitousek PM, Naylor R, Crews T, David MB, Drinkwater LE, Holland E, Johnes PJ, Katzenberger J, Martinelli LA, Matson PA, Nziguheba G, Ojima D, Palm CA, Robertson GP, Sanchez PA, Townsend AR, Zhang FS. Agriculture. Nutrient imbalances in agricultural development. Science 2009. [PMID: 19541981 DOI: 10.1126/science.ll70261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Affiliation(s)
- P M Vitousek
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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Vitousek PM, Naylor R, Crews T, David MB, Drinkwater LE, Holland E, Johnes PJ, Katzenberger J, Martinelli LA, Matson PA, Nziguheba G, Ojima D, Palm CA, Robertson GP, Sanchez PA, Townsend AR, Zhang FS. Nutrient Imbalances in Agricultural Development. Science 2009; 324:1519-20. [DOI: 10.1126/science.1170261] [Citation(s) in RCA: 893] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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13
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Evans DJ, Johnes PJ, Lawrence DS. Physico-chemical controls on phosphorus cycling in two lowland streams. Part 2--the sediment phase. Sci Total Environ 2004; 329:165-182. [PMID: 15262165 DOI: 10.1016/j.scitotenv.2004.02.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 02/20/2004] [Accepted: 02/21/2004] [Indexed: 05/24/2023]
Abstract
This article investigates the temporal and spatial controls on sediment-phosphorus (P) dynamics in two contrasting sub-catchments of the River Kennet, England. Suspended sediment (collected under representative flow conditions) and size-fractionated bedload (collected weekly for one year) from the Rivers Lambourn and Enborne was analysed for a range of physico-chemical determinands. Total P concentrations were highest in the most mobile fractions of sediment: suspended sediment, fine silt and clay and organic matter (mean concentrations of 1758, 1548 and 1440 microg P g(-1) dry sediment, respectively). Correlation analysis showed significant relationships between total P and total iron (n= 110), total manganese (n= 110), organic matter (n= 110) and specific surface area (n= 28) in the Lambourn (r2 0.71, 0.68, 0.62 and 0.52, respectively) and between total P and total iron (n= 110), total manganese (n= 110) and organic matter (n= 110) in the Enborne (r2 0.74, 0.85 and 0.68, respectively). These data highlight the importance of metal oxyhydroxide adsorption of P on fine particulates and organic matter. However, high total P concentrations in the granule gravel and coarse sand size fraction during the summer period (mean concentration 228 microg P g(-1) dry sediment) also highlight the role of calcite co-precipitation on P dynamics in the Lambourn. P to cation ratios in Lambourn sediment indicated that fine silt and clay and granule gravel and coarse sand size fractions were potential sources of P release to the water column during specific periods of the summer and autumn. In the Enborne, however, only the granule gravel and coarse sand size fraction had high ratios and a slow, constant release of P was observed. In addition, scanning electron microscopy work confirmed the association of P with calcite in the Lambourn and P with iron on clay particles in the Enborne. The study highlighted the importance of the chemical and physical properties of the sediment in influencing the mechanisms controlling P storage and release within river channels.
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Affiliation(s)
- D J Evans
- Aquatic Environments Research Centre, Department of Geography, University of Reading, Reading, RG6 6AB, UK.
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Evans DJ, Johnes PJ. Physico-chemical controls on phosphorus cycling in two lowland streams. Part 1 -- the water column. Sci Total Environ 2004; 329:145-163. [PMID: 15262164 DOI: 10.1016/j.scitotenv.2004.02.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 02/20/2004] [Accepted: 02/21/2004] [Indexed: 05/24/2023]
Abstract
This paper investigates phosphorus (P) transport and transformation dynamics in two contrasting sub-catchments of the River Kennet, England. Samples were collected daily under baseflow and hourly under stormflow conditions using autosamplers for 2 years and analysed for a range of determinands (full P fractionation, suspended sediment (SS), cations, pH, alkalinity, temperature and oxygen). Concentrations of SRP, SUP, PP and SS were higher in the flashy River Enborne (means of 0.186, 0.071, 0.101 and 34 mg l(-1), respectively) than the groundwater-fed River Lambourn (0.079, 0.057, 0.028 and 9 mg l(-1), respectively). A seasonal trend in the daily P dataset was evident, with lower concentrations during intermediate flows and the spring (caused by a dilution effect and macrophyte uptake) than during baseflow conditions. However, in the hourly P dataset, highest concentrations were observed during storm events in the autumn and winter (reflecting higher scour with increased capacity to entrain particles). Storm events were more significant in contributing to the total P load in the River Enborne than the River Lambourn, especially during August to October, when dry antecedent conditions were observed in the catchment. Re-suspension of P-rich sediment that accumulated within the channel during summer low flows might account for these observations. It is suggested that a P-calcite co-precipitation mechanism was operating during summer in the River Lambourn, while adsorption by metal oxyhydroxide groups was an important mechanism controlling P fractionation in the River Enborne. The influence of flow conditions and channel storage/release mechanisms on P dynamics in these two lowland rivers is assessed.
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Affiliation(s)
- D J Evans
- Aquatic Environments Research Centre, Department of Geography, University of Reading, Reading, RG6 6AB, UK.
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Prior H, Johnes PJ. Regulation of surface water quality in a Cretaceous Chalk catchment, UK: an assessment of the relative importance of instream and wetland processes. Sci Total Environ 2002; 282-283:159-174. [PMID: 11846069 DOI: 10.1016/s0048-9697(01)00950-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To investigate the relative importance of instream nutrient spiralling and wetland transformation processes on surface water quality, total nitrogen (TN) and total phosphorus (TP) concentrations in a 200-m reach of the River Lambourn in the south-east of England were monitored over a 2-year period. In addition, the soil pore water nutrient dynamics in a riparian ecosystem adjacent to the river were investigated. Analysis of variance indicated that TN, TP and suspended sediment concentrations recorded upstream of the wetland were statistically significantly higher (P < 0.05) than those downstream of the site. Such results suggest that the wetland was performing a nutrient retention function. Indeed, analysis of soil pore waters within the site show that up to 85% of TN and 70% of TP was removed from water flowing through the wetland during baseflow conditions, thus supporting the theory that the wetland played an important role in the regulation of surface water quality at the site. However, the small variations observed (0.034 mg TN l(-1) and 0.031 mg P l(-1)) are consistent with the theory of nutrient spiralling suggesting that both instream and wetland retention processes have a causal effect on surface water quality.
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Affiliation(s)
- H Prior
- Aquatic Environments Research Centre, Department of Geography, The University of Reading, Whiteknights, UK.
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Whitehead PG, Johnes PJ, Butterfield D. Steady state and dynamic modelling of nitrogen in the River Kennet: impacts of land use change since the 1930s. Sci Total Environ 2002; 282-283:417-434. [PMID: 11846082 DOI: 10.1016/s0048-9697(01)00927-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Steady state and dynamic models have been developed and applied to the River Kennet system. Annual nitrogen exports from the land surface to the river have been estimated based on land use from the 1930s and the 1990s. Long term modelled trends indicate that there has been a large increase in nitrogen transport into the river system driven by increased fertiliser application associated with increased cereal production, increased population and increased livestock levels. The dynamic model INCA (Integrated Nitrogen in Catchments) has been applied to simulate the day-to-day transport of N from the terrestrial ecosystem to the riverine environment. This process-based model generates spatial and temporal data and reproduces the observed instream concentrations. Applying the model to current land use and 1930s land use indicates that there has been a major shift in the short term dynamics since the 1930s, with increased river and groundwater concentrations caused by both non-point source pollution from agriculture and point source discharges.
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Affiliation(s)
- P G Whitehead
- Aquatics Environment Research Centre, Department of Geography, University of Reading, Whiteknights, UK
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