Browsing by Author "Gill, Andrew B."
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Item Open Access Application of integrated models to assess the impacts of floodplain connectivity on ecosystem services: a case study at Tempsford, UK(Cranfield University, 2015-09) Taktikos, Niko; Hess, Tim M.; Gill, Andrew B.Floodplains in the United Kingdom have evolved from natural landscapes to artificially modified ecosystems through managing lateral and vertical floodplain connectivity leading to synergy or trade-offs in ecosystem service delivery. Research methods have been limited in understanding the processes by which ecosystem service values are formed and the data required to support ecosystem service assessment. Developing a methodology while complex and challenging is necessary in order to take the ecosystem approach forward to support decision making for policy makers, planners and stakeholders. The aim of this research was to develop a method to assess the delivery of ecosystem services in response to changes in floodplain connectivity and evaluate the performance. A case study floodplain was selected at Tempsford, downstream of the River Ivel in Bedfordshire, United Kingdom as an example for opportunities to deliver multiple ecosystem services. A sequential integrated modelling system was applied utilising a linked ISIS 1D-2D hydrodynamic model and WaSim, a 1D soil water balance model to simulate changes in floodplain connectivity and generate model data to improve estimates of ecosystem services indicators. A non- monetary multi-criteria analysis methodology was applied to further develop indicators for ecosystem services assessment and to assess the impacts of the model scenarios on ecosystem services delivery. The integration of the WaSim model was unsuccessful as the model performed poorly in the calibration and validation process and was not fit for its intended purpose. It was deduced that potential groundwater seepage in the regional aquifer occurs outside of the field study site, which cannot be modelled in WaSim. To demonstrate the impact of lateral connectivity controls on the water table position, an empirical method was developed using the mean observed water table position to represent a ‘no drainage system’ vertical connectivity scenario. The results showed that in low frequency/high magnitude flood events, increasing the lateral connectivity by lowering embankments provides synergy and benefits to flood alleviation, water supply and freshwater fish habitat and trade-offs and disbenefits to flood damage, agricultural productivity, terrestrial habitat and recreation. In high frequency/low magnitude flood events, decreasing the lateral connectivity by raising embankments still provides the same synergy and trade-offs yet lower benefits and disbenefits. Marginally decreasing the lateral connectivity creates a higher level of benefits and a lower level of disbenefits to promote multi-functional land use in the floodplain. Managing the control of floodplain connectivity needs to be carefully planned to enable multifunctional land use in a floodplain.Item Open Access Assessing habitat outcomes of floodplain forest restoration: case study at the Ouse Valley Park(Cranfield University, 2016-12) Perez Linde, Natalia; Gill, Andrew B.The research project for this PhD set out to provide a best practice example of bringing together industry (Hanson Heidelberg Cement Group), a charitable body (The Parks Trust), non-departmental public body (Environment Agency) and academia (Cranfield University). The Parks Trust (landowner) and Hanson (quarry operator) worked together with the vision of creating a new floodplain forest landscape along a 1 km reach of the River Great Ouse following extraction of gravels from the site. It was the first project of its kind in the United Kingdom where planning permission was obtained specifically for the creation of a floodplain forest habitats post quarrying. The aim of the PhD research was to determine appropriate ecological approaches to apply to the assessment and future monitoring of habitat outcomes of a floodplain forest restoration project at a mineral extraction site. A central element of the research was the design of a scientifically justified monitoring programme, with key variables determined being: soil characteristics, water quality, vegetation development, site topography and water table level data. An Adaptive Monitoring Framework (AMF) was chosen to set the proposed monitoring within which was complemented with the hypothesis - The ratio of wet/dry vegetation within the floodplain forest is determined by the site topography and water table level. The hypothesis was tested by analysis of the key variables through fieldwork and existing data sources supplemented with a study of the water table level interaction with two typical floodplain forest tree species (Salix viminalis and Populus trichocarpa x deltoides) in a glasshouse experiment. Findings from the field and experimental research were then used within a spatially based landscape ecology scenario approach to identify the most suitable areas of the study site for specific species planting according to soil-water levels and topography in the floodplain forest. Outputs of this research enhance understanding of the key aspects to consider when assessing floodplain forest re-creation/restoration and enable guidelines and recommendations to be developed for land managers based on a long-term and an adaptive ecological monitoring approach. These management guidelines and recommendations based on a systematic scientific approach applied within the research should be appropriate to other similar restoration projects. The research provides the background evidence on what should be measured to determine the environmental changes of the floodplain forest habitat restoration as it develops towards restoration success.Item Open Access Assessing the cumulative environmental effects of marine renewable energy developments: establishing common ground(Elsevier, 2016-11-03) Willsteed, Edward A.; Gill, Andrew B.; Birchenough, S. N.; Jude, Simon R.Assessing and managing the cumulative impacts of human activities on the environment remains a major challenge to sustainable development. This challenge is highlighted by the worldwide expansion of marine renewable energy developments (MREDs) in areas already subject to multiple activities and climate change. Cumulative effects assessments in theory provide decision makers with adequate information about how the environment will respond to the incremental effects of licensed activities and are a legal requirement in many nations. In practise, however, such assessments are beset by uncertainties resulting in substantial delays during the licensing process that reduce MRED investor confidence and limit progress towards meeting climate change targets. In light of these targets and ambitions to manage the marine environment sustainably, reducing the uncertainty surrounding MRED effects and cumulative effects assessment are timely and vital. This review investigates the origins and evolution of cumulative effects assessment to identify why the multitude of approaches and pertinent research have emerged, and discusses key considerations and challenges relevant to assessing the cumulative effects of MREDs and other activities on ecosystems. The review recommends a shift away from the current reliance on disparate environmental impact assessments and limited strategic environmental assessments, and a move towards establishing a common system of coordinated data and research relative to ecologically meaningful areas, focussed on the needs of decision makers tasked with protecting and conserving marine ecosystems and services.Item Open Access Attribute table, evaluation data & analysis of evaluation data for published paper "Obligations and aspirations: a critical evaluation of offshore wind farm cumulative impact assessments"(Cranfield University, 2017-10-24 13:08) Willsteed, Edward A.; Jude, Simon; Gill, Andrew B.; Birchenough, SilvanaFiles uploaded enable: 1) application of the critical evaluation framework developed to other fields; 2) re-examination of the data generated by the evaluation. The full methodology is reported in the published paper. Information identifying individual Environmental Statements has been removed from publicly available data.Item Open Access Best practices for monitoring and assessing the ecological response to river restoration(MDPI, 2021-11-26) England, Judy; Angelopoulos, Natalie; Cooksley, Susan; Dodd, Jennifer; Gill, Andrew B.; Gilvear, David; Johnson, Matthew; Naura, Marc; O’Hare, Matthew; Tree, Angus; Wheeldon, Jennifer; Wilkes, Martin A.Nature-based solutions are widely advocated for freshwater ecosystem conservation and restoration. As increasing amounts of river restoration are undertaken, the need to understand the ecological response to different measures and where measures are best applied becomes more pressing. It is essential that appraisal methods follow a sound scientific approach. Here, experienced restoration appraisal experts review current best practice and academic knowledge to make recommendations and provide guidance that will enable practitioners to gather and analyse meaningful data, using scientific rigor to appraise restoration success. What should be monitored depends on the river type and the type and scale of intervention. By understanding how habitats are likely to change we can anticipate what species, life stages, and communities are likely to be affected. Monitoring should therefore be integrated and include both environmental/habitat and biota assessments. A robust scientific approach to monitoring and appraisal is resource intensive. We recommend that appraisal efforts be directed to where they will provide the greatest evidence, including ‘flagship’ restoration schemes for detailed long-term monitoring. Such an approach will provide the evidence needed to understand which restoration measures work where and ensure that they can be applied with confidence elsewhere.Item Open Access Critical evaluation of ecosystem changes from an offshore wind farm: producing natural capital asset and risk registers(Elsevier, 2022-08-17) Causon, Paul D.; Jude, Simon; Gill, Andrew B.; Leinster, PaulOffshore wind infrastructure modifies benthic habitats, affecting ecosystem services. A natural capital approach allows risks to nature-based assets and ecosystem benefits to be assessed. The UK Natural Capital Committee produced guidance for conducting natural capital assessments to aid decision making processes. Development of an asset register and risk register are key components of this methodology. The former provides an inventory of NC stocks, and the latter considers the likelihood of changes and the scale of their impact on delivery of ecosystem services. In this study, suitability of the methodology in a marine environment context was critically evaluated. Natural capital stocks before and after installation of Greater Gabbard offshore wind farm were compared and risks to delivery of ecosystem services were assessed. It was demonstrated that incorporating an assessment of impacts on natural capital assets in planning and management decisions (as an extension to traditional environmental impact assessment approaches) could further facilitate sustainable use of marine ecosystems. For example, by preventing access to bottom-trawl fisheries activities, wind farms may promote recovery and increase value of seabed natural capital assets. By also introducing aquaculture systems loss of food provision (from reduced fishing activity) could be offset whilst allowing benthic natural capital assets to recover. Natural capital assessment is relevant to the marine context. However, application of the Natural Capital Committee’s methodology was constrained by the limited coverage of standard benthic sampling tools. Given the scale of wind energy plans across the marine environment it is recommended that these shortcomings are appropriately addressed.Item Open Access Developing a novel approach to assess the cumulative effects of human activities to support contemporary marine management and planning(Cranfield University, 2019-06) Willsteed, Charles Edward Allan; Jude, Simon; Gill, Andrew B.; Birchenough, Silvana N. R.The challenges of assessing and managing the cumulative impacts of human activities on the environment remain major obstacles to sustainable development. This challenge is highlighted by the worldwide expansion of marine renewable energy developments (MREDs) in areas already subject to multiple activities and where climate change is rapidly changing the environment. Cumulative effects assessments (CEAs) in theory provide decision makers with adequate information about how the environment will respond to the incremental effects of licensed activities and are a legal requirement in many nations. In practise, however, such assessments are beset by uncertainties that, in context of MREDs, resulting in substantial delays during the licensing process that limit progress towards meeting carbon emission reduction targets. At a broader level, poor CEA practice risks developments and activities being permitted that contribute to environmental degradation with negative implications for connected human societies. This thesis investigates the origins of CEA to understand why improved practice remains challenging and to identify key CEA considerations that need to be addressed to improve CEA. Shortcomings in current practice were evaluated to refine the key CEA considerations. A conceptual analysis of the underpinnings of CEA was completed that resulted in a tiered conception of CEA being proposed to support regional coherence between CEAs, and the elaboration of principles and a CEA pathway to support consistent CEA practice. The CEA pathway was tested by defining and collating evidence to populate the steps of the pathway, which was then applied to a case-study to investigate the potential for novel approaches to support improved CEA. Insights and directions for future research were discussed to contribute to the evidence base required to improve CEA and to advocate for a change in CEA, from being a sub-discipline of project- and plan- level assessments, to becoming the overarching purpose of such assessments.Item Open Access Early life sensory ability—ventilatory responses of thornback ray embryos (Raja clavata) to predator-type electric fields(Wiley, 2015-10-30) Ball, Rachel Emma; Oliver, Matthew Kenneth; Gill, Andrew B.Predator avoidance is fundamental for survival and it can be particularly challenging for prey animals if physical movement away from a predatory threat is restricted. Many sharks and rays begin life within an egg capsule that is attached to the sea bed. The vulnerability of this sedentary life stage is exacerbated in skates (Rajidae) as the compulsory ventilatory activity of embryos makes them conspicuous to potential predators. Embryos can reduce this risk by mediating ventilatory activity if they detect the presence of a predator using an acute electrosense. To determine how early in embryonic life predator elicited behavioral responses can occur, the reactions of three different age groups (1/3 developed, 2/3 developed, and near hatching) of embryonic thornback rays Raja clavata were tested using predator-type electric field stimuli. Egg capsules were exposed to continuous or intermittent stimuli in order to assess varying predator-type encounter scenarios on the ventilatory behavior of different developmental stages. All embryos reacted with a “freeze response” following initial electric field (E-field) exposure, ceasing ventilatory behavior in response to predator presence, demonstrating electroreceptive functionality for the first time at the earliest possible stage in ontogeny. This ability coincided with the onset of egg ventilatory behavior and may represent an effective means to enhance survival. A continuous application of stimuli over time revealed that embryos can adapt their behavior and resume normal activity, whereas when presented intermittently, the E-field resulted in a significant reduction in overall ventilatory activity across all ages. Recovery from stimuli was significantly quicker in older embryos, potentially indicative of the trade-off between avoiding predation and adequate respiration. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 721–729, 2016Item Open Access Effects of EMFs from Undersea Power Cables on Elasmobranchs and Other Marine Species.(2011-05-31T00:00:00Z) Tricas, Timothy; Gill, Andrew B.Anthropogenic electromagnetic fields (EMFs) have been introduced into the marine environmentaround the world and from a wide variety of sources for well over a century. Despite this, littleis known about potential ecological impacts from EMFs. For decades, power transmissioncables have been installed across bays and river mouths, and connecting near-shore islands to themainland, with little consideration of possible effects to marine species from EMFs. At a time ofgreater environmental awareness, the US now faces the possibility of a new source of EMFs overa much greater extent of the seabed from offshore renewable energy facilities in coastal waters.This literature review synthesizes information on the types of power cables and models theexpected EMFs from representative cables. Available information on electro- and magnetosensitivityof marine organisms, including elasmobranchs (sharks and rays) and other fishspecies, marine mammals, sea turtles, and invertebrates is summarized and used in conjunctionwith the power cable modeling results to evaluate the level of confidence the existing state ofknowledge provides for impact assessment. Gaps in our knowledge of power cablecharacteristics and the biology needed to understand and predict impacts are summarized andform the basis of recommendations for future research priorities. Potential mitigationopportunities are described with a discussion of their potential secondary impacts as well assuggested methods for monitoring mitigation effectiveness. Finally, because interest in offshorerenewable energy has increased throughout US coastal waters, there is a concern that organismscould be exposed to multiple seabed power cables. Cumulative effects of this exposure are discussed.Item Open Access Effects of Pile-driving Noise on the Behaviour of Marine Fish(2010-03-31T00:00:00Z) Mueller-Blenkle, Christina; McGregor, Peter K.; Gill, Andrew B.; Andersson, Mathias H.; Metcalfe, Julian; Bendall, Victoria; Sigray, Peter; Wood, Daniel T.; Thomsen, FrankStudies on the effects of offshore wind farm construction on marine life have so far focussed onbehavioural reactions in porpoises and seals. The effects on fish have only very recently come intothe focus of scientists, regulators and stakeholders. Pile-driving noise during construction is ofparticular concern as the very high sound pressure levels could potentially prevent fish from reachingbreeding or spawning sites, finding food, and acoustically locating mates. This could result in longtermeffects on reproduction and population parameters. Further, avoidance reactions might result indisplacement away from potential fishing grounds and lead to reduced catches. However, reactionthresholds and therefore the impacts of pile-driving on the behaviour of fish are completely unknown.We played back pile-driving noise to cod and sole held in two large (40 m) net pens located in a quietBay in West Scotland. Movements of the fish were analysed using a novel acoustic tracking system.Received sound pressure level and particle motion were measured during the experiments.There was a significant movement response to the pile-driving stimulus in both species at relativelylow received sound pressure levels (sole: 144 – 156 dB re 1μPa Peak; cod: 140 – 161 dB re 1 μPaPeak, particle motion between 6.51x10-3 and 8.62x10-4 m/s2 peak). Sole showed a significantincrease in swimming speed during the playback period compared to before and after playback. Codexhibited a similar reaction, yet results were not significant. Cod showed a significant freezingresponse at onset and cessation of playback. There were indications of directional movements awayfrom the sound source in both species. The results further showed a high variability in behaviouralreactions across individuals and a decrease of response with multiple exposures.This study is the first to document behavioural response of marine fish due to playbacks of pile-drivingsounds. The results indicate that a range of received sound pressure and particle motion levels willtrigger behavioural responses in sole and cod. The results further imply a relatively large zone ofbehavioural response to pile-driving sounds in marine fish. Yet, the exact nature and extent of thebehavioural response needs to be investigated further. Some of our results point toward habituationto the sound.The results of the study have important implications for regulatory advice and the implementation ofmitigation measures in the construction of offshore wind farms in the UK and elsewhere. First, theconcerns raised about the potential effects of pile-driving noise on fish were well founded. Thissuggests to both regulators and developers that the costs imposed by some mitigation measures thathave so far been applied following the precautionary principle go some of the way to addressing areal problem. We also suggest that our behavioural thresholds are considered in assessments ofimpacts of offshore wind farms in the UK and elsewhere. Mitigation measures should be furtherdiscussed developed and, if meaningful, applied especially if these could lead to a reduction ofacoustic energy that is emitted into the water column.Further studies should investigate the response at critical times (e.g. mating and spawning) and theeffects of pile-driving on communication behaviour. It will also be necessary to further investigatehabituation to the sound to effectively manage effects of pile-driving sound on marine fish.Item Open Access Elasmobranch cognitive ability: using electroreceptive foraging behaviour to demonstrate learning, habituation and memory in a benthic shark(Springer Science Business Media, 2014-01-31T00:00:00Z) Kimber, Joel A.; Sims, David W.; Bellamy, Patricia H.; Gill, Andrew B.Top predators inhabiting a dynamic environment, such as coastal waters, should theoretically possess sufficient cognitive ability to allow successful foraging despite unpredictable sensory stimuli. The cognition-related hunting abilities of marine mammals have been widely demonstrated. Having been historically underestimated, teleost cognitive abilities have also now been significantly demonstrated. Conversely, the abilities of elasmobranchs have received little attention, despite many species possessing relatively large brains comparable to some mammals. The need to determine what, if any, cognitive ability these globally distributed, apex predators are endowed with has been highlighted recently by questions arising from environmental assessments, specifically whether they are able to learn to distinguish between anthropogenic electric fields and prey bioelectric fields. We therefore used electroreceptive foraging behaviour in a model species, Scyliorhinus canicula (small-spotted catshark), to determine cognitive ability by analysing whether elasmobranchs are able to learn to improve foraging efficiency and remember learned behavioural adaptations. Positive reinforcement, operant conditioning was used to study catshark foraging behaviour towards artificial, prey-type electric fields (Efields). Catsharks rewarded with food for responding to Efields throughout experimental weeks were compared with catsharks that were not rewarded for responding in order to assess behavioural adaptation via learning ability. Experiments were repeated after a 3-week interval with previously rewarded catsharks this time receiving no reward and vice versa to assess memory ability. Positive reinforcement markedly and rapidly altered catshark foraging behaviour. Rewarded catsharks exhibited significantly more interest in the electrical stimulus than unrewarded catsharks. Furthermore, they improved their foraging efficiency over time by learning to locate and bite the electrodes to gain food more quickly. In contrast, unrewarded catsharks showed some habituation, whereby their responses to the electrodes abated and eventually entirely ceased, though they generally showed no changes in most foraging parameters. Behavioural adaptations were not retained after the interval suggesting learned behaviour was not memorised beyond the interval. Sequences of individual catshark search paths clearly illustrated learning and habituation behavioural adaptation. This study demonstrated learning and habituation occurring after few foraging events and a memory window of between 12 h and 3 weeks. These cognitive abilities are discussed in relation to diet, habitat, ecology and anthropogenic Efield sources. © 2013 Springer-Verlag Berlin Heidelberg.Item Open Access Elasmobranch electroreceptive foraging behaviour: male-female interactions, choice and cognitive ability(Cranfield University, 2008-08) Kimber, J. A.; Gill, Andrew B.; Sims, D. W.Aspects of electroreceptive foraging behaviour were investigated in a benthic elasmobranch, Scyliorhinus canicula (small-spotted catshark). The findings build on current knowledge of sexual conflict in this species and provide novel information concerning differentiation ability, choice and cognition relating to elasmobranch electroreceptive foraging behaviour. Hierarchical catshark behaviours towards artificial, prey-type electric fields (E fields) following stimulation by food-derived scent were recorded under laboratory conditions. Experiment 1: Male-female interactions Foraging behaviour of single- and mixed-sex catshark groups were investigated using electroreception as a proxy for feeding levels. Results indicated significant reductions in foraging levels of being grouped with the opposite sex, in addition to higher responsiveness in females. These attributes are most likely consequences of differing reproductive strategies and resultant sexual conflict. Experiment 2: Choice Catsharks were trained to swim through narrow tunnels and upon exit were presented with two differing E fields simultaneously. Choices were recorded and analysed, and thereby their ability to distinguish between and/or show preferences for fields was determined. Differentiation ability was demonstrated by preferences for stronger rather than weaker direct current fields, and alternating rather than direct current fields. The fish were either unable to distinguish or showed no preference for artificial (electrodes) and natural fields (crabs). Experiment 3: Cognitive ability Response levels and changes in response levels over time of catsharks rewarded for responding to E fields were compared to those of catsharks that were not rewarded. Results demonstrated learning and habituation behaviour improving foraging efficiency over short time scales according to profitability of fields. Failure to retain altered behaviour after an interval indicated short memory windows. These attributes would prove beneficial in a variable environment. Given many elasmobranchs’ continuing population declines and increasing potential interactions with anthropogenic E fields, such information will hopefully benefit both fisheries managers and offshore renewable energy developers.Item Open Access Environmental and ecological effects of ocean renewable energy development: a current synthesis(The Oceanographic Society; 1999 / The Oceanography Society (TOS), 2010-12-31T00:00:00Z) Boehlert, G. W.; Gill, Andrew B.Marine renewable energy promises to assist in the effort to reduce carbon emissions worldwide. As with any large-scale development in the marine environment, however, it comes with uncertainty about potential environmental impacts, most of which have not been adequately evaluated—in part because many of the devices have yet to be deployed and tested. We review the nature of environmental and, more specifically, ecological effects of the development of diverse types of marine renewable energy—covering marine wind, wave, tidal, ocean current, and thermal gradient—and discuss the current state of knowledge or uncertainty on how these effects may be manifested. Many of the projected effects are common with other types of development in the marine environment; for example, additional structures lead to concerns for entanglement, habitat change, and community change. Other effects are relatively unique to marine energy conversion, and specific to the type of energy being harnessed, the individual device type, or the reduction in energy in marine systems. While many potential impacts are unavoidable but measurable, we would argue it is possible (and necessary) to minimize others through careful device development and site selection; the scale of development, however, will lead to cumulative effects that we must understand to avoid environmental impacts. Renewable energy developers, regulators, scientists, engineers, and ocean stakeholders must work together to achieve the common dual objectives of clean renewable energy and a healthy marine environment. - See more at: http://www.tos.org/oceanography/archive/23-2_boehlert.html#sthash.MBJIR5sa.dpufItem Open Access Field-based measurement of hydrodynamics associated with engineered in-channel structures: the example of fish pass assessment(Cranfield University, 2016-03) Kriechbaumer, Thomas; Rivas Casado, Monica; Blackburn, Kim; Gill, Andrew B.The construction of fish passes has been a longstanding measure to improve river ecosystem status by ensuring the passability of weirs, dams and other in- channel structures for migratory fish. Many fish passes have a low biological effectiveness because of unsuitable hydrodynamic conditions hindering fish to rapidly detect the pass entrance. There has been a need for techniques to quantify the hydrodynamics surrounding fish pass entrances in order to identify those passes that require enhancement and to improve the design of new passes. This PhD thesis presents the development of a methodology for the rapid, spatially continuous quantification of near-pass hydrodynamics in the field. The methodology involves moving-vessel Acoustic Doppler Current Profiler (ADCP) measurements in order to quantify the 3-dimensional water velocity distribution around fish pass entrances. The approach presented in this thesis is novel because it integrates a set of techniques to make ADCP data robust against errors associated with the environmental conditions near engineered in-channel structures. These techniques provide solutions to (i) ADCP compass errors from magnetic interference, (ii) bias in water velocity data caused by spatial flow heterogeneity, (iii) the accurate ADCP positioning in locales with constrained line of sight to navigation satellites, and (iv) the accurate and cost-effective sensor deployment following pre-defined sampling strategies. The effectiveness and transferability of the methodology were evaluated at three fish pass sites covering conditions of low, medium and high discharge. The methodology outputs enabled a detailed quantitative characterisation of the fish pass attraction flow and its interaction with other hydrodynamic features. The outputs are suitable to formulate novel indicators of hydrodynamic fish pass attractiveness and they revealed the need to refine traditional fish pass design guidelines.Item Open Access Impact of deforestation on habitat connectivity thresholds for large carnivores in tropical forests(Springer, 2017-07-13) Zemanova, Miriam A.; Perotto-Baldivieso, Humberto L.; Dickins, Emily L.; Gill, Andrew B.; Leonard, John P.; Wester, David B.Introduction Deforestation significantly impacts large carnivores that depend on large tracts of interconnected forest habitat and that are sensitive to human activities. Understanding the relationship between habitat use and spatial distribution of such species across human modified landscapes is critical when planning effective conservation strategies. This study assessed the presence of potential landscape connectivity thresholds resulting from habitat fragmentation associated with different deforestation patterns using a scale-based approach that links species-specific home ranges with the extent of anthropogenic activities. The objectives were (1) to quantify the spatial and temporal distribution of natural vegetation for five common deforestation patterns and (2) to evaluate the connectivity associated with these patterns and the existence of potential thresholds affecting jaguar dispersal. The Bolivian lowlands, located within jaguar conservation units, were analysed with landscape metrics to capture the spatial and temporal changes within deforested areas and to determine potential impact on jaguar connectivity and connectivity thresholds for dispersal. Results Over the period of 1976–2005, the amount of natural vegetation has decreased by more than 40% in all locations with the biggest changes occurring between 1991 and 2000. Landscape spatial structure around jaguar locations showed that jaguars used areas with mean proportion of natural areas = 83.14% (SE = 3.72%), mean patch density = 1.16 patches/100 ha (SE = 0.28 patches/100 ha), mean patch area = 616.95 ha (SE = 172.89 ha) and mean edge density = 705.27 m/ha (SE = 182.19 m/ha).We observed strong fragmentation processes in all study locations, which has resulted in the connectivity of jaguar habitat decreasing to <20% by 2005. A connectivity threshold zone was observed when the proportion of natural vegetation was less than 58.4% (SE = 1.3). Conclusions Assessing fragmentation and connectivity for carnivores within the extent of human-modified landscapes proved to be an effective way to understand the changes caused by deforestation and their potential effects on large carnivore habitats. Our study highlights the importance of scale-based approaches for assessing current conservation challenges to protect large carnivores.Item Open Access Linking ecosystem services with epibenthic biodiversity change following installation of offshore wind farms(Elsevier, 2018-09-01) Causon, Paul D.; Gill, Andrew B.The growing awareness of climate change and the recognised need to secure energy production has been a driving force behind the expansion of the offshore wind industry across the world. Benefits from offshore wind farms (OWFs) may extend further than low CO2 energy production. Wind turbine substructures introduce hard surfaces that are rapidly colonised by epibenthic marine organisms, altering biomass and biodiversity within the local ecosystem. Biodiversity plays a critical role in supporting ecosystem processes and functions that maintain ecosystem services. As offshore wind development continues to grow and modify marine habitats, changes in biodiversity could affect the provision of ecosystem services. In this context, this review sets out to capture the current understanding of epibenthic biodiversity change following the installation of OWFs and attempt to link these changes in biodiversity with marine ecosystem services through the associated processes and functions.Item Open Access Literature review on the potential effects of electromagnetic fields and subsea noise from marine renewable energy developments on Atlantic salmon, sea trout and European eel. Scottish Natural Heritage Commissioned Report(2011-02-28T00:00:00Z) Gill, Andrew B.; Bartlett, Mark D.Background This report reviews the current state of knowledge with regard to the potential for three fish species of conservation importance, namely Atlantic salmon (Salmo salar), sea trout (Salmo trutta) and European eel (Anguilla anguilla), to be affected by marine renewable energy developments (MRED). The focus is on marine wave and tidal power developments that will generate electricity offshore, which will then be transferred to land by subsea cable. During construction and operation, the marine renewable energy (MRE) devices are expected to cause a number of disturbances to the marine environment including electromagnetic fields (EMF) emissions and subsea sounds (generally referred to as ‘noise'). Such disturbances were assessed to meet the following aims: To determine the current understanding of the effects of EMFs and noise associated with the installation and operation of MREDs, on the behaviour of three species: S. salar, S. trutta and A. anguilla. To determine the gaps in current knowledge and identify research requirements.Main findings The availability and quality of the information on which to base the review was found to be limited with respect to all aspects of the fishes migratory behaviour and activity, both before and after MRE development; this makes it difficult to establish cause and effect. The main findings were: S. salar and A. anguilla can use the earth's magnetic field for orientation and direction finding during migrations. S. trutta juveniles, and close relatives of S. trutta, respond to both the earth's magnetic field and artificial magnetic fields. Current knowledge suggests that EMFs from subsea cables and cabling orientation may interact with migrating eels (and possibly salmonids) if their migration or movement routes take them over the cables, particularly in shallow waters (<20m).The effect, if any, could be a relatively trivial temporary change in swimming direction, or potentially a more serious avoidance response or delay to migration. Whether this will represent a biologically significant effect cannot yet be determined. S. salar, S. trutta and A. anguilla are likely to encounter EMF from subsea cables either during the adult movement phases of life or their early life stages during migration within shallow, coastal waters adjacent to the natal rivers. The subsea noise from MRE devices has not been suitably characterised to determine its acoustic properties and propagation through the coastal waters. MREDs that require pile driving during construction appear to be the most relevant to consider, in addition to the time scale over which pile driving is carried out, for the species under investigation. In the absence of a clear understanding of their response to subsea noise, the specific effects on S. salar, S. trutta and A. anguilla remain very difficult to determine for Scottish waters in relation to tidal and wave power. Based on the studies reviewed, it is suggested that fish that receive high intensity sound pressures (i.e. close proximity to the MRED construction) may be negatively impacted to some degree, whereas those at distances of 100's to 1000's of metres may exhibit behaviour responses, the impact of which is unknown and will be dependent on the received sound. During operation there may be more subtle behavioural effects that should be considered over the life time of the MRED. Whether these effects will represent biologically significant impacts cannot yet be determined. The current assumptions of limited effects are built on an incomplete understanding of how the three species move around their environment and interact with natural and anthropogenic EMF and subsea noise. A number of gaps in understanding exist, principally whether S. salar, S. trutta and A. anguilla respond to the EMF and/or the noise associated with MREDs in Scottish waters. A number of suggestions for specific studies are highlighted in the final section of the report.Item Open Access Modification of benthic ecosystems by offshore wind farms: implications for natural capital and ecosystem services(2019-05) Causon, Paul; Leinster, Paul; Gill, Andrew B.; Brennan, FeargalDue to concerns about climate change and energy security there has been considerable growth in the installed capacity of offshore wind energy worldwide over the last two decades. Owing to engineering constraints offshore wind turbines have generally been installed in areas characterised by soft sediments. Offshore wind farms introduce hard substrate and intertidal zones into these areas and have the capacity to alter natural capital, including biodiversity, in benthic ecosystems. Changes in benthic habitats may result in changes to the ecosystem services (goods and benefits people receive from nature) provided by natural functions and processes. Thus, continued expansion in offshore wind energy has the potential to affect natural capital and the associated delivery of ecosystem services. Differences in benthic community composition between manufactured structures, natural rock reefs and soft sediments in the southern North Sea were found to be significant (P <0.05) through permutational analysis of variance (PERMANOVA). However, evidence suggests that ecosystem functioning remained similar between natural substrata and offshore energy structures. Based on a Monte-Carlo analysis there were no significant differences in trait expression between the habitat types for the most dominant taxa. There were significant differences in feeding mode, longevity and larval duration amongst less common taxa (P <0.05), however their effect is likely to be muted. An assessment of natural capital demonstrated that offshore wind farms present risks and benefits to natural capital and the associated ecosystem services. The Thanet offshore wind farm was used as a case study. Overall, the natural capital increased following the installation of the wind farm. Targeted investment to support natural capital within offshore wind farms can produce functional ecosystems that not only produce low carbon energy but also augment ecosystem services; a number of which can have economic benefits. The findings have implications for the design, operation, maintenance and end of life treatment of offshore windfarms.Item Open Access Non-consumptive effects of native and invasive predators on juvenile Caribbean parrotfish(Springer, 2016-04-30) Eaton, Lewis; Sloman, Katherine A.; Wilson, Rod W.; Gill, Andrew B.; Harborne, Alastair R.Non-consumptive effects of predators can have important impacts on aquatic food webs, but there are few data on how predators change the behaviour of Caribbean reef fishes. Such changes may include behavioural responses to the invasive predatory lionfish (Pterois volitans/P. miles). This study used an aquarium experiment to examine the behaviour of herbivorous parrotfish (Scarus iseri) in the absence of other fish (control), with a non-piscivore present, and with a predatory threat from a native grouper or lionfish. Treatments were repeated with and without additional parrotfish shelters to examine the potential effects of degraded reefs (loss of refuges). Using video, parrotfish behaviours (sheltering, swimming in open areas, foraging, aggressive conspecific interactions, bite rates, and shoaling behaviour) were recorded for groups of four parrotfish. Compared to the control, the average number of parrotfish hiding was reduced by 65 % and foraging shoals were 10 % larger when threatened by grouper, likely as a specific response to an ambush predator. When exposed to lionfish, parrotfish reduced their bite rates by 50 %, possibly to be more vigilant of this predator’s unique stalking behaviour. The absence of additional shelter had limited effects although parrotfish formed 10 % larger shoals when swimming in open water, potentially as a defensive behaviour because of a perceived lack of refuges. The reduction in parrotfish bite rates caused by lionfish may have important demographic consequences. Furthermore, parrotfishes are important grazers of macroalgae, and these behavioural changes may exacerbate the direct effects of lionfish predation and potentially affect reef benthic dynamics.Item Open Access Obligations and aspirations: A critical evaluation of offshore wind farm cumulative impact assessments(Elsevier, 2017-09-04) Willsteed, Edward A.; Jude, Simon; Gill, Andrew B.; Birchenough, Silvana N. R.Proponents of marine renewable energy worldwide highlight that regulatory and consenting procedures are a significant barrier to the upscaling of infrastructure required to transform the energy generation sector. Uncertainties about the cumulative effects of marine renewable energy developments cause substantial delays during the consenting process, which are exacerbated by the lack of clarity about how to assess cumulative effects. These obstacles have contributed to perceptions that this essential emerging industry receives disproportionate scrutiny relative to established maritime activities. However, alongside legislated targets to reduce carbon emissions, there are legal obligations to protect, maintain and improve the condition of the marine environment. As the imperative to halt the decline in the condition of the environment increases, so expectations of cumulative impact assessments grow and the risk of consenting delays persists. To investigate how robust current cumulative impact assessment practise is, a novel evaluation framework was developed and applied to Environmental Statements of the world's largest offshore wind farms, currently in United Kingdom waters. The framework was designed to evaluate cumulative impact assessments relative to the information needs of decision-makers tasked with managing cumulative effects. We found that current practise does not meet those needs, that there is dissonance between science and practise, and problematic variability between assessments was observed. Straightforward recommendations for improved practise are provided, which if implemented may ease the perceived regulatory burden by clarifying practise. We also highlight additional steps that could enable project-led cumulative impact assessments to better support regional marine management. The results and recommendations will be of interest to countries worldwide where marine renewable energy is emerging alongside ecosystem-approach and marine spatial planning aspirations.