Bowburn Consultancy

Durham, United Kingdom

Bowburn Consultancy

Durham, United Kingdom
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Kelly M.,Bowburn Consultancy
Journal of Ecology and Environment | Year: 2013

Diatoms have become an integral part of the UK's freshwater monitoring strategy over the past two decades, mostly in response to increasingly stringent European Union (EU) legislation. The use of diatoms is based on strong correlations between diatom assemblages and environmental variables, and from knowledge of the "expected" (= "reference") state of each river. The nationwide overview of the ecological health of rivers this gives allows those stretches of rivers which fail to meet EU criteria to be identified. This, in turn, allows appropriate remediation measures to be planned. Because diatom assemblages vary in space and time, even within a single water body, effective use of diatoms requires a consistent approach in order to minimise uncertainty. This includes the use of methods which comply with European Standards, a training and accreditation scheme for analysts, and a suite of quality assurance methods. Those aspects of uncertainty that cannot be readily controlled have been quantified and all estimates of ecological status are accompanied by the appropriate "confidence of class" and "risk of misclassification". This, in turn, helps planners prioritise those locations which are most likely to benefit from remediation. © 2013 The Ecological Society of Korea.


Schneider S.C.,Norwegian Institute for Water Research | Kahlert M.,Swedish University of Agricultural Sciences | Kelly M.G.,Bowburn Consultancy
Science of the Total Environment | Year: 2013

Eutrophication and acidification are among the major stressors on freshwater ecosystems in northern Europe and North America, but possible consequences of interactions between pH and nutrients on ecological status assessment and species richness patterns have not previously been assessed. Using data from 52 river sites throughout Norway, we investigated the combined effects of pH and nutrients on benthic algae assemblages, specifically 1) taxa-specific couplings between nutrient and acidity traits, 2) the degree of consistency between different biotic indices, separately for nutrients and acid conditions, 3) the impact of pH on nutrient indices and phosphorus on indices of acid conditions, and 4) the impact of pH and phosphorus supply on diatom and non-diatom taxon richness. We found that 1) acid-tolerant taxa are generally associated with nutrient-poor conditions, with only a few exceptions; this is probably more a consequence of habitat availability than reflecting true ecological niches; 2) correlation coefficients between nutrient indices and TP, as well as acid conditions indices and pH were barely affected when the confounding factor was removed; 3) the association of acid-tolerant taxa with nutrient-poor conditions means that the lowest possible nutrient index at a site, as indicated by benthic algae, is lower at acid than at circumneutral sites. Although this may be an artifact of the datasets from which taxa-specific indicator values were derived, it could lead to a drift in nutrient indices with recovery from acidification; 4) the response of non-diatom taxon richness follows a complex pattern with a synergistic interaction between nutrient supply and pH. In contrast, diatom richness follows a simple additive pattern; this suggests structural differences between diatoms and non-diatom benthic algae in their response to nutrient supply and pH; diatom taxon richness tended to increase with nutrient supply, while non-diatom richness decreased. © 2012 Elsevier B.V.


The Water Framework Directive (WFD) embodies concepts of "ecological health". This essay extends this metaphor, looking at the ways in which ecologists should diagnose and treat "sick" ecosystems. Recent practice in the UK has been to develop multifunctional ecologists to act as ecological equivalents of "family doctors". This requires methods that can be used without high levels of specialisation and, in turn, allows individuals to gain deep knowledge of particular geographic areas. This system is under threat both from new scientific developments and from management innovations designed to reduce costs. The next stages of WFD implementation, however, will see a shift towards locally based problem-solving, where inherent uncertainties will require the exercise of professional judgement above and beyond evidence-based science. We need to encourage "breadth" as well as "depth" in ecological assessment methods and a three-tiered framework for this is described. © 2013 Elsevier Ltd.


Kelly M.,Bowburn Consultancy
Ecological Indicators | Year: 2011

Many diatom-based methods have been proposed in recent years. Besse-Lototskaya et al. (2011) compare some of those developed for assessing inorganic nutrients. However, they fail to address the two questions of greatest interest to those who wish to use such metrics to inform decision-making. These questions are: what is the role of diatom-based trophic metrics in environmental management in Europe in the twenty-first century and do these indices represent causal relationships with underlying pressure gradients? The present economic climate means that Member States of the European Union will look more critically at all methods for assessing freshwater quality and developers need to ensure that their methods are "fit-for-purpose". © 2011 Elsevier Ltd.


Birk S.,University of Duisburg - Essen | Willby N.J.,University of Stirling | Kelly M.G.,Bowburn Consultancy | Bonne W.,European Commission - Joint Research Center Ispra | And 4 more authors.
Science of the Total Environment | Year: 2013

Halting and reversing the deterioration of aquatic ecosystems requires concerted action across state boundaries and administrative barriers. However, the achievement of common management objectives is jeopardised by different national quality targets and ambitions. The European Water Framework Directive requires that quality classifications are harmonised via an intercalibration exercise, ensuring a consistent level of ambition in the protection and restoration of surface water bodies across the Member States of the European Union. We outline the key principles of the intercalibration methodology, review the achievements of intercalibration and discuss its benefits and drawbacks. Less than half of the required intercalibration has been completed, mostly due to a lack of national assessment methods. The process has fostered a scientific debate on ecological classification with important implications for environmental management. Despite a significant level of statistical abstraction, intercalibration yielded a fundamental and unified vision of what constitutes good ecology across Europe, in principle ensuring greater parity in the funds invested to achieve good ecological status. © 2013 Elsevier B.V.


Kelly M.,Bowburn Consultancy
European Journal of Phycology | Year: 2013

The Water Framework Directive (WFD) provides the legal basis for water management in the European Union (EU). Twelve years after it was passed, all but five EU Member States had phytobenthos assessment methods for rivers, whilst nine had methods for lakes. Most are based on diatoms, although a few are supplemented by evaluations of non-diatoms and some include macroalgae as part of parallel macrophyte assessments. Norway is the exception, with assessment based on non-diatom algae alone. Over half of all states have methods based wholly or partly on weighted average metrics developed before the onset of the WFD, with nine choosing the Indice de Polluosensibilité Specifique. Such metrics generally have high correlations with the predominant nutrient or organic pollution gradient and, as such, represent pragmatic solutions to ecological status assessment. However, their widespread use raises questions about what, exactly, 'ecological status' means. Strong relationships with chemical pressure gradients may be a mixed blessing as pressure gradients are often composed of several intercorrelated variables, making it difficult to disentangle correlation and causation in the absence of ecophysiological studies of individual species. Moreover, the focus on strong relationships with chemical gradients means that most phytobenthos metrics describe the scale of hazard at a site rather than the risk posed to other trophic levels and to ecosystem services. This first generation of phytobenthos assessment tools may be inadequate when catchment managers need guidance on remediation strategies for particular water bodies. A second generation of assessment tools, focused on the fitness of the phytobenthos as part of aquatic ecosystems, rather than just as indicators of chemical conditions, is needed if the goal of good ecological status around Europe is to be achieved. © 2013 © British Phycological Society.


Trobajo R.,IRTA - Institute of Agricultural-Alimentary Research and Technology | Rovira L.,IRTA - Institute of Agricultural-Alimentary Research and Technology | Ector L.,Center De Recherche Public Gabriel Lippmann | Wetzel C.E.,Center De Recherche Public Gabriel Lippmann | And 2 more authors.
Diatom Research | Year: 2013

The taxonomy of several small-celled, ecologically significant Nitzschia species, which are frequently confused with each other or whose names are misapplied, is clarified. Following an examination of type material and modern samples by light and electron microscopy, it was concluded that N. frustulum (Kützing) Grunow, N. inconspicua Grunow, N. soratensis E. Morales & Vis and N. invisitata Hustedt are independent species. No morphological basis was found for separating N. frustulum var. subsalina Hustedt or N. boliviana E. Morales & Vis from N. inconspicua and they are therefore placed in synonymy with N. inconspicua. Nitzschia soratensis, described recently from Bolivia, has previously been misidentified in Europe, either as N. inconspicua (from which it differs most obviously in having more bluntly rounded poles, striae within the raphe canal that are composed of triplets, and fibulae that can be seen in light microscopy to widen at their bases) or as N. abbreviata Hustedt ex Simonsen (from which it differs in pore ultrastructure). Nitzschia frustulum resembles N. inconspicua in every morphological feature examined, but with wider valves and consistently higher maximum length. © 2012 The International Society for Diatom Research.


Kelly M.G.,Bowburn Consultancy | Zgrundo A.,University of Gdansk
Diatom Research | Year: 2013

The use of instruments such as toothbrushes for sampling diatoms from hard surfaces is a potential source of uncertainty in ecological status assessments as diatoms may be inadvertently transferred from one sample to another. The scale of this contamination was investigated by sampling two sites differing in a number of key environmental properties resulting in different diatom assemblages. Fewer than 1% of the total valves counted represented taxa that might have been transferred between samples and this had no significant effect on the values of diatom-based indices calculated from the two sites. © 2013 The International Society for Diatom Research.


Denicola D.M.,Slippery Rock University | Kelly M.,Bowburn Consultancy
Freshwater Science | Year: 2014

Assessment of ecological integrity is the basis for sustainable management of the ecosystem services lakes provide. Periphyton is used in stream assessment, but lake assessment is based mostly on water-column variables. We addressed the use of periphyton to assess lakes, how factors influence responses of periphyton metrics, and whether periphyton provides unique information for determining biological condition and identifying risks. Much effort directed at using periphyton for assessment has focused on linear relationships between taxonomic metrics and single stressors. These relationships can be good proxies for water chemistry, but do not always represent biological conditions. Community diversity is difficult to relate to stressors because low values may result from natural conditions (grazing, disturbance). Quantile regression, River Invertebrate Prediction and Classification System (RIVPACS)-type models, and taxonomic distinctiveness may provide more precise indicators. Periphyton biomass and productivity are linked closely to trophic status but are rarely used in assessment. Responses of these variables over a trophic gradient are often nonlinear, and surrogate metrics that use quantile regression or weighted-averaging calibration/regression based on community composition may overcome this problem for assessment. Measures, such as alkaline phosphatase activity, number of N-fixing taxa, and periphyton nutrient stoichiometry can be used to assess littoral-zone ecosystem function and to help establish causative effects of stressors. The value added by periphyton-based assessment is that it provides higher-level understanding of the ecological status of the littoral zone. Assessment must be rooted in a strong understanding of the science and must provide guidance and cost-effective options for lake managers. We outline a hierarchy for periphyton assessment methods that assess risk at different levels of effort and precision. © 2014 by The Society for Freshwater Science.


Kelly M.G.,Bowburn Consultancy | Ector L.,Center De Recherche Public Gabriel Lippmann
Hydrobiologia | Year: 2012

Intercalibration of ecological status class boundaries between member states is a requirement of the European Union's Water Framework Directive. Although a preliminary intercalibration of boundaries established for phytobenthos has been performed, a number of questions remain, including the extent to which variations in taxonomic concepts used in different member states influences the position of these boundaries. In this paper, the robustness of the diatom-based metrics used for intercalibration is assessed. Whilst use of genus-level identification led to a loss of ecological information, merging representatives of closely-related taxa has little effect on these metrics. Similarly, taxa that occur only rarely or never have high relative abundances in a dataset can also be ignored without the loss of ecological information. Similar results were obtained when modern taxonomic concepts were compared with concepts in use 80 years ago. Fine scale taxonomy may play a valuable role within member states; however, our results suggest that, at a continental scale, a simplified approach to diatom taxonomy should not affect intercalibration results. © 2012 Springer Science+Business Media B.V.

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