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John N. Lester - One of the best experts on this subject based on the ideXlab platform.
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Public perceptions and attitudes towards a forthcoming Managed Realignment scheme: Freiston Shore, Lincolnshire, UK
Ocean & Coastal Management, 2003Co-Authors: L.b. Myatt, Mark D. Scrimshaw, John N. LesterAbstract:Abstract Managed Realignment is viewed as a sustainable flood defence strategy by practitioners as it provides environmental and economic benefits in light of potential global climate change. However, in many cases social barriers are in existence, with public perception and attitudes towards this approach less than favourable, as there is always resistance in surrendering land to the sea. Freiston Shore Managed Realignment scheme is the second of three on-going studies that aim to detect the drivers surrounding public acceptance of Managed Realignment and confidence in the Environment Agency, the lead agency for Managed Realignment in the UK. This research presents the hypothesis that local residents will be more accepting of a fully established scheme (since it will have been in the public domain for longer), rather than at its inception or during its construction. Findings from the Freiston scheme showed that the majority of residents supported the Managed Realignment scheme at its current construction phase, although two main barriers were identified as suppressing public acceptance. These are public confidence in the Environment Agency and public understanding of coastal defence and Managed Realignment issues. This investigation recommends that local community engagement activities are effective means of addressing such deficiencies whilst providing the education necessary for understanding the requirements and limitations of Managed Realignment. However, such participation activities should be tailored for the needs of individual target audiences.
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Public perceptions and attitudes towards an established Managed Realignment scheme: Orplands, Essex, UK.
Journal of environmental management, 2003Co-Authors: L.b. Myatt, Mark D. Scrimshaw, John N. LesterAbstract:Where appropriate, Managed Realignment is the preferred policy option for sustainable coastal defences in the UK, since it provides both economic and ecological advantages. Until recently however, research has failed to address the social implications of this policy option having only acknowledged that communities in general, show reluctance in conceding land to the sea. Orplands Managed Realignment scheme is the third in a series of case studies to address a variety of social issues, but with a particular focus on the public acceptance of schemes and public confidence in the Environment Agency. It is hypothesised that local residents will be more accepting of a Realignment scheme the longer it is in the public domain, rather than at its inception or construction. This paper presents findings from the Orplands scheme and demonstrates that overall scheme acceptance was greater at this site in comparison to previous case studies. Despite this, respondents did not show any more confidence in the Environment Agency and this has been attributed to their general scepticism towards a statutory body and the lack of recent contact between the various stakeholders. It is suggested that the development of criteria for consultation and public participation would facilitate public acceptance of Managed Realignment schemes.
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Solid phase partitioning of metals in Managed Realignment soils: laboratory studies in timed soil sea-water batch mixtures
Applied Geochemistry, 2001Co-Authors: R. H. C. Emmerson, Mark D. Scrimshaw, Jason W. Birkett, John N. LesterAbstract:Abstract Geochemical interactions between agricultural soil and sea-water at a salt marsh restoration Managed Realignment site in Essex, UK were simulated through a series of laboratory experiments. Soil from the site was mixed with sea-water for 0–30 days in batch reactors. The resulting soil residue was subjected to a modified version of the Tessier sequential extraction procedure involving leaching with 5 reagents of progressively increasing strength. Differences in total metals extracted by the series of sequential extractions in comparison to a single digest hindered interpretation of data. Analysis of the sequential extracts and residual sea-water for a suite of metals revealed that Na, Mg and K were sorbed from sea-water to the soils, and from the readily exchangeable fraction of the soil, Ba, Ca, Mn, Ni and Zn were depleted. In the more strongly held fractions extractability of a number of metals, most notably Al, Fe and K by acid leaches was observed to increase as a result of contact with sea-water. The extractability of the heavy metals Cr, Pb, Ni and Zn from these tightly held fractions was also observed to increase as a result of sea-water mixing. However, results imply that tidal inundation of the soils at the site will not result in significant leaching of metals to the environment.
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Flood defence in the Blackwater Estuary, Essex, UK: the impact of sedimentological and geochemical changes on salt marsh development in the Tollesbury Managed Realignment site.
Marine Pollution Bulletin, 2001Co-Authors: Y. H. Chang, Mark D. Scrimshaw, C. L. Macleod, John N. LesterAbstract:Recent changes in the UK's coastal defence strategy have resulted in the introduction of Managed Realignment (MR), a technique which attempts to establish salt marshes on low-lying coastal farmland. This work investigates the impact of MR, in particular on the interactions between sediment movement, changes in heavy metal concentrations and salt marsh development. Pre- and post-inundation samples were collected and analysed between 1995 and 1997. Sediment transport patterns (1996) demonstrated that sediment particles were distributed by tides around the site, resulting in a change in the spatial distribution of the metals which was related to the sediment particle size distribution. Despite the presence of some metal contaminants found within the MR site, vegetated salt marsh has developed since 1997. However, heavy metals such as Cu, Mn, Ni, Pb and Zn exhibited relative depletion in the sediment developing with salt marsh in 1997, which is in agreement with data indicating that concentrations of metals within sediments is related to frequency of tidal inundation. During initial development of the site, sediment transport was the main factor controlling metal distribution, however, subsequently the frequency of tidal inundation became the most significant factor. Further work may allow for prediction of how future MR sites will develop with respect to redistribution of sediments and subsequent transport of contaminants in the dissolved phase.
Jonathan Potts - One of the best experts on this subject based on the ideXlab platform.
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Public perception of Managed Realignment: Brancaster West Marsh, North Norfolk, UK
Marine Policy, 2002Co-Authors: L.b. Myatt-bell, M.d. Scrimshaw, J.n. Lester, Jonathan PottsAbstract:In an attempt to provide more sustainable and environmentally acceptable coastal defence options, engineers and policy-makers alike are increasingly turning to ‘softer’ approaches such as Managed Realignment. However, gaining public acceptance of Managed Realignment schemes can be challenging given that the local communities often view Managed Realignment as ‘giving in’ to the sea (Coastal defences: processes, problems and solutions. UK, Routledge, 2001). By studying public perceptions, engineers, planners and policy-makers will have a better understanding of the public's reactions, concerns and issues of Managed Realignment, which not only fills the existing research gap but also promotes public awareness and knowledge alongside the consultation process. This paper reviews findings from a pilot study conducted at a public exhibition and meeting in Brancaster, North Norfolk. Questionnaire surveys were used to collect the data and address three main research objectives (1) to gain an insight into the locals’ perceptions of flooding in Brancaster; (2) to assess their awareness of the Managed Realignment scheme; and (3) identify the main issues that they considered to be important. The results demonstrated that many variables influence public perceptions of Managed Realignment, including personal experience, lack of information and media influence. The study concludes that while there is no formula to calculate which variables come into play, researching public perception towards Managed Realignment projects must be addressed by following a case-by-case approach.
Andrew B. Cundy - One of the best experts on this subject based on the ideXlab platform.
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Sediment structure and physicochemical changes following tidal inundation at a large open coast Managed Realignment site
The Science of the total environment, 2018Co-Authors: Jonathan Dale, Kate L. Spencer, H.m. Burgess, Andrew B. Cundy, Simon J. Carr, Ian W. Croudace, David J. NashAbstract:Managed Realignment (MR) schemes are being implemented to compensate for the loss of intertidal saltmarsh habitats by breaching flood defences and inundating the formerly defended coastal hinterland. However, studies have shown that MR sites have lower biodiversity than anticipated, which has been linked with anoxia and poor drainage resulting from compaction and the collapse of sediment pore space caused by the site's former terrestrial land use. Despite this proposed link between biodiversity and soil structure, the evolution of the sediment sub-surface following site inundation has rarely been examined, particularly over the early stages of the terrestrial to marine or estuarine transition. This paper presents a novel combination of broad- and intensive-scale analysis of the sub-surface evolution of the Medmerry Managed Realignment Site (West Sussex, UK) in the three years following site inundation. Repeated broad-scale sediment physiochemical datasets are analysed to assess the early changes in the sediment subsurface and the preservation of the former terrestrial surface, comparing four locations of different former land uses. Additionally, for two of these locations, high-intensity 3D-computed X-ray microtomography and Itrax micro-X-ray fluorescence spectrometry analyses are presented. Results provide new data on differences in sediment properties and structure related to the former land use, indicating that increased agricultural activity leads to increased compaction and reduced porosity. The presence of anoxic conditions, indicative of poor hydrological connectivity between the terrestrial and post-inundation intertidal sediment facies, was only detected at one site. This site has experienced the highest rate of accretion over the terrestrial surface (ca. 7 cm over 36 months), suggesting that poor drainage is caused by the interaction (or lack of) between sediment facies rather than the former land use. This has significant implications for the design of future MR sites in terms of preparing sites, their anticipated evolution, and the delivery of ecosystem services.
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The evolution of embryonic creek systems in a recently inundated large open coast Managed Realignment site
Anthropocene Coasts, 2018Co-Authors: Jonathan Dale, H.m. Burgess, Niall Burnside, Paul Kilkie, David J. Nash, Andrew B. CundyAbstract:Managed Realignment (MR) schemes are being implemented to compensate for the degradation of coastal habitats. However, evidence suggests that MR sites have lower biodiversity than anticipated, which has been linked to poor drainage. Despite creek networks playing an important role in enhancing site drainage in natural intertidal environments, there remains a shortage of data on the formation and evolution of creeks within MR sites. This study evaluates creek development at the Medmerry Managed Realignment Site, UK. Creek development is investigated using differential global positioning system (dGPS) data, supported by sedimentological analyses and a high-resolution digital surface model (DSM) derived from images taken using a small unmanned aerial vehicle. Measurements indicated that creeks will develop relatively quickly, but are influenced by differences in the sub-surface sedimentological conditions. A suitable level of agreement was found between the DSM and dGPS measurements, demonstrating the approp...
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Hydrodynamics and sedimentary processes in the main drainage channel of a large open coast Managed Realignment site
Estuarine Coastal and Shelf Science, 2018Co-Authors: Jonathan Dale, H.m. Burgess, David J. Nash, Andrew B. CundyAbstract:Abstract Managed Realignment (MR) is becoming increasingly popular with many coastal managers and engineers. Monitoring of MR sites has provided growing evidence that many of the saltmarshes created in these environments have lower biodiversity than naturally formed intertidal marshes, and may not fully deliver the anticipated ecosystem services such as carbon sequestration and coastal flood defence. Despite the importance of the sedimentary environment in developing an intertidal morphology suitable for plant establishment and succession, the evolution of the sediment erosion, transportation, deposition and consolidation cycle in newly breached sites is rarely examined. This study evaluates the hydrodynamics and concentration of suspended sediment exported and imported along the main drainage channel within the Medmerry Managed Realignment Site, West Sussex, UK, the largest open coast Realignment in Europe (at the time of breaching). Measurements were taken over a one year period (November 2015–October 2016) at the breach, at the landwards extremity where freshwater drains into the site, and in an excavated channel in the centre of the site. At the latter site, 1.7 cm of sediment accreted over the study period. Suspended sediment concentration (SSC) measurements indicate that, under ambient conditions, sediment is imported into and exported from the Medmerry site, although similar concentrations of sediment were recorded being internally redistributed around the site (typically 0.11 g/l measured in the breach area compared to 0.12 g/l measured in the centre of the site). Sediment is removed from the site following large (1–2 mm/hour) rainfall events, which take several tidal cycles to drain through the site. Peaks in SSC corresponding with lower intensity rainfall events, especially during periods when the intertidal mudflats have been exposed, have also been observed. Analysis of the hydrodynamics and patterns of sedimentation during and following storm occurrences (the 2015-16 Storms Eva, Imogen and Katie) however demonstrate the relative resilience (i.e. rapid recovery and minimal disturbance) of the site to extreme storm events.
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Sedimentation rhythms and hydrodynamics in two engineered environments in an open coast Managed Realignment site
Marine Geology, 2017Co-Authors: Jonathan Dale, H.m. Burgess, Andrew B. CundyAbstract:Managed Realignment (MR) schemes are considered by many coastal managers and engineers to be a preferable method of coastal flood defence and compensating for habitat loss, by creating new areas of intertidal saltmarsh and mudflat habitat. Monitoring of MR sites has tended to focus on short term ecological factors, resulting in a shortage of high frequency, high resolution long term measurements of the evolution of the sediment erosion, transportation, deposition and consolidation cycle (ETDC) in newly breached sites. This is particularly true of analysis of the formation and preservation of sedimentary rhythmites and evaluations of sedimentation rates (and their variability) in newly inundated intertidal environments. This study provides an evaluation of sedimentation rhythms and hydrodynamics from two contrasting sites within the Medmerry Managed Realignment scheme, the largest open coast Realignment in Europe (at the time of site inundation). Bed sediment altimeter data highlighted different sedimentation patterns at the two sites; near constant deposition of sediment occurred near the breach resulting in 15.2 cm of sediment being accreted over the one year monitoring period, whereas periodic accretion and erosion of sediment occurred inland leading to 2.7 cm of net accretion. Differences in the relationship between suspended sediment concentrations and site hydrodynamics were observed on a semi-diurnal to annual scale. This study highlights the need for further consideration of the sedimentation processes in MR schemes in order to enhance the design and construction of these sites. Advancements in the understanding of these processes will increase the success of MR schemes in terms of the evolution of the sediment regime and the ecosystem services provided, particularly as they are more widely accepted as a form of coastal flood defence and intertidal habitat creation method.
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Physicochemical changes in sediments at Orplands Farm, Essex, UK following 8 years of Managed Realignment
Estuarine Coastal and Shelf Science, 2008Co-Authors: Kate L. Spencer, Andrew B. Cundy, R. G. Hughes, S. Davies-hearn, Simon Turner, C. L. MacleodAbstract:Managed Realignment (MR) is a ‘soft’ engineering technique that involves the deliberate landwards retreat of the existing line of coastal defence and subsequent tidal inundation of land. Managed Realignment has been established worldwide for over 30 years and its goals may include habitat restoration, recovery of biodiversity and sustainable coastal defence. In southeast England in particular, an increasing number of MR sites (20–110 ha) have been commissioned in the last decade in response to increasing coastal habitat loss and sea-level rise. Following initial sea wall breaching and site flooding, monitoring of these sites is usually carried out for a period of 5 years and during this time changes in ecosystem structure can be easily observed. However, there is a poor understanding of the long-term effects of flooding on soil physicochemical parameters including sediment geochemistry and geochemical cycling, nutrient fluxes and soil maturation processes. Such physical and chemical changes may continue to take place over time-scales exceeding 5 years and therefore current monitoring practices may not be sufficient. This paper examines the changes in the physicochemical parameters of sediments in vertical core sections at the Orplands Farm MR site, Blackwater Estuary, Essex, 8 years after its flooding in 1995. Post-breach sediment accumulation rates at the site have been determined and a multi-proxy approach has been used to identify a pre-breach land surface. Soil development and the vertical distribution of saltmarsh plants following breaching have also been examined. The species saturation index approach has been used to provide an indication of the success of MR at this site. The pre-breach land surface was identified at 4–6 cm depth indicating a sediment accumulation rate ca. 0.75 cm a?1 since the site was breached in 1995. This sedimentation rate exceeds the regional sea-level rise of 0.1–0.3 cm a?1 and hence marsh development at the site is expected to continue in the short term. The examination of physicochemical parameters with depth indicates that the pre-breach land surface forms a barrier that may inhibit vertical tidal flushing, nutrient transfer and contaminant removal. The vegetation was mostly a pioneer and low-mid marsh assemblage typical of the area, although the species saturation index is low compared to other European sites and this may be attributed to a range of factors including poor drainage at the site and reduced seed availability.
Kate L. Spencer - One of the best experts on this subject based on the ideXlab platform.
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Sediment structure and physicochemical changes following tidal inundation at a large open coast Managed Realignment site
The Science of the total environment, 2018Co-Authors: Jonathan Dale, Kate L. Spencer, H.m. Burgess, Andrew B. Cundy, Simon J. Carr, Ian W. Croudace, David J. NashAbstract:Managed Realignment (MR) schemes are being implemented to compensate for the loss of intertidal saltmarsh habitats by breaching flood defences and inundating the formerly defended coastal hinterland. However, studies have shown that MR sites have lower biodiversity than anticipated, which has been linked with anoxia and poor drainage resulting from compaction and the collapse of sediment pore space caused by the site's former terrestrial land use. Despite this proposed link between biodiversity and soil structure, the evolution of the sediment sub-surface following site inundation has rarely been examined, particularly over the early stages of the terrestrial to marine or estuarine transition. This paper presents a novel combination of broad- and intensive-scale analysis of the sub-surface evolution of the Medmerry Managed Realignment Site (West Sussex, UK) in the three years following site inundation. Repeated broad-scale sediment physiochemical datasets are analysed to assess the early changes in the sediment subsurface and the preservation of the former terrestrial surface, comparing four locations of different former land uses. Additionally, for two of these locations, high-intensity 3D-computed X-ray microtomography and Itrax micro-X-ray fluorescence spectrometry analyses are presented. Results provide new data on differences in sediment properties and structure related to the former land use, indicating that increased agricultural activity leads to increased compaction and reduced porosity. The presence of anoxic conditions, indicative of poor hydrological connectivity between the terrestrial and post-inundation intertidal sediment facies, was only detected at one site. This site has experienced the highest rate of accretion over the terrestrial surface (ca. 7 cm over 36 months), suggesting that poor drainage is caused by the interaction (or lack of) between sediment facies rather than the former land use. This has significant implications for the design of future MR sites in terms of preparing sites, their anticipated evolution, and the delivery of ecosystem services.
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Potential contaminant release from agricultural soil and dredged sediment following Managed Realignment
Journal of Soils and Sediments, 2012Co-Authors: Margaret Kadiri, Kate L. Spencer, Catherine M. HeppellAbstract:Purpose Laboratory experiments were conducted to examine the potential for metal (Cu, Ni and Zn) and herbicide (simazine, atrazine and diuron) release from agricultural soil and dredged sediment in Managed Realignment sites following tidal inundation. Materials and methods Column microcosm and batch sorption experiments were carried out at low (5 practical salinity units, psu) and high (20 psu) salinity to evaluate the changes in the partitioning of metals and herbicides between the soil/sediment and the aqueous phase, and the release of metals and herbicides from soil/sediment to the overlying water column. Results and discussion For both the metals and herbicides, the highest contaminant loads were released from the sediment within the first 24 h of inundation suggesting that any negative impacts to overlying water quality in a Managed Realignment scheme will be relatively short term following tidal inundation of soil and sediment. The release of metals was found to be dependent on a combination of salinity effects and the strength of binding of the metals to the soil and sediment. In the case of the herbicides, salinity impacted on their release. Particulate organic carbon was found to control the binding and release of the herbicides, highlighting the importance of assessing soil and sediment organic matter content when planning Managed Realignment sites. Conclusions Our research demonstrates that metals and herbicides may be released from contaminated sediments and agricultural soils during initial periods of flooding by seawater in Managed Realignment sites.
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Potential contaminant release from agricultural soil and dredged sediment following Managed Realignment
Journal of Soils and Sediments, 2012Co-Authors: Margaret Osikhofe Kadiri, Kate L. Spencer, Catherine M. HeppellAbstract:Purpose Laboratory experiments were conducted to examine the potential for metal (Cu, Ni and Zn) and herbicide (simazine, atrazine and diuron) release from agricultural soil and dredged sediment in Managed Realignment sites following tidal inundation.
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Sediment characteristics of a restored saltmarsh and mudflat in a Managed Realignment scheme in Southeast England
Hydrobiologia, 2011Co-Authors: Margaret Kadiri, Kate L. Spencer, Catherine M. Heppell, Paul FletcherAbstract:Sediment characteristics and vegetation composition were measured in a restored and natural saltmarsh and mudflat at Wallasea Island Managed Realignment scheme (Essex, UK) from January to December 2007. The similar sediment characteristics in the restored and natural mudflat indicated that the sediment in the restored mudflat was approaching natural conditions. However, the sediment characteristics in the restored saltmarsh were not becoming similar to those in the natural saltmarsh. The sediment moisture content, organic matter content and porosity were lower while the sediment bulk density, salinity and pH were higher in the restored compared to the natural saltmarsh. The dissimilarities were mainly due to differences in the vegetation abundance and organic matter content. Although, 18 months after restoration the restored saltmarsh was only sparsely vegetated and there was no net change in the sediment characteristics, the occurrence of Salicornia europaea L. demonstrated that pioneer saltmarsh vegetation establishment preceded the development of sediment characteristics.
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Physicochemical changes in sediments at Orplands Farm, Essex, UK following 8 years of Managed Realignment
Estuarine Coastal and Shelf Science, 2008Co-Authors: Kate L. Spencer, Andrew B. Cundy, R. G. Hughes, S. Davies-hearn, Simon Turner, C. L. MacleodAbstract:Managed Realignment (MR) is a ‘soft’ engineering technique that involves the deliberate landwards retreat of the existing line of coastal defence and subsequent tidal inundation of land. Managed Realignment has been established worldwide for over 30 years and its goals may include habitat restoration, recovery of biodiversity and sustainable coastal defence. In southeast England in particular, an increasing number of MR sites (20–110 ha) have been commissioned in the last decade in response to increasing coastal habitat loss and sea-level rise. Following initial sea wall breaching and site flooding, monitoring of these sites is usually carried out for a period of 5 years and during this time changes in ecosystem structure can be easily observed. However, there is a poor understanding of the long-term effects of flooding on soil physicochemical parameters including sediment geochemistry and geochemical cycling, nutrient fluxes and soil maturation processes. Such physical and chemical changes may continue to take place over time-scales exceeding 5 years and therefore current monitoring practices may not be sufficient. This paper examines the changes in the physicochemical parameters of sediments in vertical core sections at the Orplands Farm MR site, Blackwater Estuary, Essex, 8 years after its flooding in 1995. Post-breach sediment accumulation rates at the site have been determined and a multi-proxy approach has been used to identify a pre-breach land surface. Soil development and the vertical distribution of saltmarsh plants following breaching have also been examined. The species saturation index approach has been used to provide an indication of the success of MR at this site. The pre-breach land surface was identified at 4–6 cm depth indicating a sediment accumulation rate ca. 0.75 cm a?1 since the site was breached in 1995. This sedimentation rate exceeds the regional sea-level rise of 0.1–0.3 cm a?1 and hence marsh development at the site is expected to continue in the short term. The examination of physicochemical parameters with depth indicates that the pre-breach land surface forms a barrier that may inhibit vertical tidal flushing, nutrient transfer and contaminant removal. The vegetation was mostly a pioneer and low-mid marsh assemblage typical of the area, although the species saturation index is low compared to other European sites and this may be attributed to a range of factors including poor drainage at the site and reduced seed availability.
Michael Elliott - One of the best experts on this subject based on the ideXlab platform.
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What Future for the English Coastline? Managed Realignment Benefits and Their Value Estimate Transferability
Studies in Ecological Economics, 2015Co-Authors: Tiziana Luisetti, Michael Elliott, Julian E. Andrews, Tim Jickells, Rk Turner, Marije Schaafsma, Nicola Beaumont, S. J. Malcolm, Daryl Burdon, Christopher AdamsAbstract:This chapter provides a study of two Managed Realignment cases in comparable estuarine systems located on the English North Sea coast: the Blackwater estuary and the Humber estuary. Two scenarios of salt marsh expansion and reduction in these estuaries are used to analyse the multiple research challenges that arise, including value transfer and stock and flow issues. The coastal ecosystems are complex and require a thorough natural science understanding of conflicting ecosystem services changes. Moreover, net economic benefits of Managed Realignment can be demonstrated, but they are context and scale dependent and valuation practices and results should reflect this. The chapter offers some solutions and suggestions for further research on these generic research challenges for coastal ecosystem management.
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Managed Realignment as compensation for the loss of intertidal mudflat: A short term solution to a long term problem?
Estuarine Coastal and Shelf Science, 2010Co-Authors: Krysia Mazik, Will Musk, Oliver Dawes, Katya Solyanko, Sue Brown, Lucas Mander, Michael ElliottAbstract:Intertidal mudflats are critical to the functional ecology of estuaries yet large areas are being lost as a result of land claim, erosion and coastal squeeze. This study examines whether Managed Realignment (at Paull Holme Strays, Humber estuary) can realistically achieve compensation for the loss of intertidal mudflat in the long term. Typical estuarine species quickly colonised the site with the total number of species recorded from the site as a whole being almost equal to that in the reference area within one year. Comparable biomass between the two areas was achieved after 2 years. However, organism abundance remains an order of magnitude lower within the Realignment site compared to outside. Community structure within the Realignment has changed from one characterised by terrestrial/freshwater organisms and early colonising species to one composed of typically estuarine species. However, the developing benthic communities only represent those typical of the estuary in areas of low elevation and high inundation frequency. Rapid accretion has favoured saltmarsh colonisation in much of the Realignment site and this is expected to increase as accretion proceeds with invertebrate colonisation being inhibited by increasing elevation. Hence, Realignment to restore intertidal mudflats can only be a short term solution in sites of high tidal elevation and in a dynamic and turbid estuary with high natural accretion rates, such as the Humber.
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Physical and biological development of a newly breached Managed Realignment site, Humber estuary, UK.
Marine Pollution Bulletin, 2007Co-Authors: Krysia Mazik, J.e. Smith, A. Leighton, Michael ElliottAbstract:As part of the Humber flood defence upgrade works (Urgent works) undertaken by the Environment Agency, the Paull Holme Strays site was identified as one of twelve potential Managed Realignment sites within the Humber catchment. The site was breached in September 2003, creating 80 hectares of new intertidal habitat. Initial accretion monitoring commenced in December 2003 with annual surveys of invertebrate colonisation commencing in October 2004. The present study gives details of the physical development of the newly created mudflat within the site, together with invertebrate colonisation and benthic community change over time. Comparisons between the newly created habitat and the existing mudflat outside the old sea wall are made. The macrofaunal communities found within the area as a whole are considered to be characteristic of the area with low species diversity, high abundance and small body size. The community within the Managed Realignment site is still in an early successional stage with low abundance and diversity in comparison with other sites within this part of the Humber. However the community biomass increased considerably between 2004 and 2005. Colonisation within the Managed Realignment site is still primarily concentrated in the areas around the two breach sites and is thought to be restricted in other areas due to infrequent tidal inundation.
