Mark Everard

Quality assessment using River Habitat Survey data

1. A representative sample of habitat features from rivers in the UK and Isle of Man has been generated by River Habitat Survey (RHS) during 1994–1997. This baseline reference provides a sound basis for describing the physical character and assessing the habitat quality of 500 m lengths of river shown on 1:250 000 scale maps and classified for water quality purposes. 2. The use of a standard field method, with associated accreditation controls, stratified random sampling strategy and computer database all provide a robust foundation for habitat quality assessment. The outputs have a sound statistical basis and satisfy the practical needs of river management as well as providing policy-makers with relevant information. 3. Within the UK, sites of national, regional, or local importance for wildlife habitat quality can be determined, using criteria based on the presence of features of known conservation interest. The occurrence, individually, of rare features, or rare combinations of representative features, can also be used to identify sites of particular regional or local importance for their river habitat quality. 4. A habitat quality assessment (HQA) scoring system, based on features considered to be of wildlife importance can be used to compare sites surveyed by the RHS method. However, for meaningful results this comparison must involve the same river type. 5. For completeness, the HQA scores for a given river type can be calibrated using known top quality sites. For individual sites, HQA scores should be used in conjunction with a measure of artificial modification to the channel. A simple Habitat Modification Score (HMS) system can be applied to RHS data for this purpose. 6. RHS can be further developed to define and predict the likely distribution of sites which satisfy the known habitat requirements of certain aquatic and riparian species. It can also provide the basis for better understanding of the spatial relationships between geomorphological processes and habitat type.

Why should the habitat‐level approach underpin holistic river survey and management?

1. The UKs new River Habitat Survey (RHS) is founded upon the assumption that species depend upon habitats and that higher habitat heterogeneity supports higher biodiversity in river channels, riparian zones and floodplains. 2. The paper reviews the evidence for this assumption. Physical habitats—of substrate and velocity conditions—are created by predictable physical forces acting within the river ‘continuum’, modified by colonization and metabolism of biota. Numerous studies have shown that habitats have distinct biotic assemblages. 3. River management has, in the past, generally simplified habitat structure but, in order to mitigate the worst effects and restore damaged rivers, it is necessary to have a sound understanding of this term as it applies to all components of the river system (channel, riparian zone and floodplain). 4. RHS has a nested approach to river channel habitats and at one level, ‘functional habitats’, the link between river processes and river biodiversity has been demonstrated. ‘The functional habitats’ concept is now used in river management for mitigation of engineering channel works and restoration of drought-damaged rivers. 5. Similar nested approaches still need to be developed in the riparian zone and river-influenced floodplain. Sustainable river management needs to come to terms with the dynamic nature of river habitat change as well as to quantify the economic benefits which habitats provide.

Rediscovering the value of urban rivers

Rivers commonly serve as defining, founding features of human settlements, yet urbanisation has degraded them, often to the extent that they no longer provide the services to society from which the settlements developed. Urban river restoration has expanded in recent years and part of this can be attributed to the increased recognition of the interconnected benefits that restored ecosystems can provide to society. This paper reviews the impact of urbanisation on rivers and the ecosystem services that they provide, and explores the ecosystem approach to restoration. Techniques and tools for the practical application of the ecosystem services approach in conservation are considered, with reference to case studies. There is a need to internalise ecosystem service insights into pragmatic, transparent and readily-used and understood planning tools, based on the capacities of a range of ecosystem services in river corridors. This is necessary if we are to avoid the continued erosion of critical resources such as rivers, rediscovering their multiple values to society, and to accelerate the translation of these sustainability concepts into applied tools.

Geochemical and physical characteristics of river and lake sediments at Naivasha, Kenya

Prior studies on Lake Naivasha relevant to understanding sediment dynamics include a bathymetric map, a paleolimnological study of fossil invertebrate assemblages in lake sediment, an overview of lake level fluctuations throughout the 20th century, and identification of a dynamic assemblage of macrophyte zones that has responded both to these changes in lake level and to more recent, alien species. Sediment samples collected from the rivers systems and the lake were examined physically and chemically. River sediment characteristics reflect geology and geomorphological processes in the catchment, whereas lake sediment stratigraphy has responded to past lake level changes. Such changes have caused significant changes in aquatic vegetation assemblages. Present day sediment dynamics in the lake are governed by the presence of river point sources in the north and wave-induced re-suspension, such that sediments introduced by rivers are transported in easterly and southerly directions, and are eventually deposited in the eastern, central and southern parts of the lake. Sedimentary deposition is also occurring in northern areas that once were protected by papyrus swamp vegetation but now only have a narrow fringe, highlighting the important role of swamp vegetation in filtering out suspended particulates and thereby controlling water quality in the lake. Geochemical analyses of river and lake sediments indicate that they represent fairly undisturbed background conditions. Higher-than-expected concentrations of cadmium, iron, nickel and zinc found in both river and lake sediment are likely to derive from volcanic rocks and/or lateritic soils found in the lake catchment.

Exploring barriers to and opportunities for the co-management of air quality and carbon in South West England: a review of progress

Due to the common sources of emissions of both air quality pollutants and greenhouse gases, management measures directed at one category of emissions are likely to positively impact the other. Through the local air quality management (LAQM) process, local authorities are required to monitor and measure specified air pollutants, the sources of which are also common to the primary sources of carbon emissions at a local level. This research tracks the progression of local authority management of carbon emissions and examines the barriers and opportunities for the integration of carbon emissions into the LAQM process. Results are triangulated from three core research methods deployed in South West England: a time series of local authority questionnaire surveys; secondary data analysis of active Air Quality Action Plans; and case study interviews of six local authorities in the region. The research concludes that the absence of statutory targets for carbon emission reductions remains a substantial barrier for local authority carbon management initiatives. However, in order to utilise scarce resources in the most efficient manner, local authorities should draw upon the existing skill set of their Air Quality Officers.

Realizing the value of fluvial geomorphology

ABSTRACT Fluvial geomorphological forms and processes exert a fundamental influence on riverine processes and functions. They thereby contribute significantly to beneficial services for humanity, yet remain largely undervalued. Major ecosystem service studies to date tend to overlook the contribution of geodiversity and geomorphological processes, particularly of fluvial geomorphology, to human well-being. Yet, management of the water environment which overlooks fundamental driving processes, such as those encompassed by fluvial geomorphology, is inherently unsustainable. Inferences from the literature highlight a broad range of contributions of fluvial processes and forms to the four ecosystem service categories of the Millennium Ecosystem Assessment, contributing to system functioning, resilience and human well-being. Fluvial geomorphologists can help society better address sustainability challenges by raising the profile of fluvial forms and processes to continuing human well-being and system resilience. To achieve this, we identify three challenges: (1) cross-disciplinary collaboration, addressing interrelations between biodiversity and geodiversity as well as broader scientific disciplines; (2) quantification to an appropriate level and, where possible, mapping of service generation and benefit realization; and (3) persuasive demonstration projects emphasizing how investment in this aspect of the natural environment can enhance service provision and net human benefits. We explore lessons learnt from case studies on river rehabilitation, floodplain management, and mapping ecosystem services. We contend that linking fluvial geomorphology to societal well-being outcomes via the language of ecosystem services provides a pathway towards social and economic recognition of relevance, influencing policy-makers about their importance and facilitating their ‘mainstreaming’ into decision-making processes. We also advance a prototype conceptual model, guiding fluvial geomorphologists better to articulate the contribution to a sustainable flow of services through better characterization of: (1) interactions between anthropogenic pressures and geomorphology; (2) how forms and processes contribute to ecosystem services; and (3) guidance on better management reflecting implications for service provision.

The Feasibility of Developing Multi-Taxa Indicators for Landscape Scale Assessment of Freshwater Systems

Abstract The use of bird assemblages as wetland indicators is now well established in the UK. An indicator based on a single taxonomic group can, however, have limitations. Conversely, a multi-taxa approach can potentially provide a more robust reflection of the health of fresh waters. In this paper, we consider the inherent suitability of different taxonomic groups for inclusion in a multi-taxa indicator, based upon taxon characteristics, species richness and prevalence across a range of freshwater habitats, and their practical suitability, based upon quality and quantity of available data. We conclude that, in addition to birds, there are six candidate groups of taxa throughout the world that are currently suitable for inclusion in a multi-taxa indicator. These are: mammals, amphibians and reptiles, fish, dragonflies and damselflies (based on adult recording), benthic macroinverte-brates and macrophytes. Of these taxa, all but amphibians and reptiles and fish are suitable for inclusion in a UK indicator. The types and limitations of currently available datasets are reviewed. We provide recommendations for advancing this approach in the assessment of freshwater systems.

Integrating local air quality and carbon management at a regional and local governance level: a case study of south west England

This paper examines the relationship between the policy process for local authority management of air quality and local government initiatives and strategies for carbon mitigation. It seeks to explore the policy and process linkages between the sources of carbon emissions and air quality pollutants in order to assess the potential benefits and/or limitations of an integrated approach for their co-management at a local and regional governance level. Local authorities, as environmental regulators, have a significant role in the UK’s attempts to tackle the problems associated with climate change. This paper describes the extent to which non-statutory management of carbon emissions is undertaken at a local governance level in south west England and examines the extent to which carbon emissions and local air quality management are integrated and co-managed at local and regional governance levels. Results are presented from a questionnaire survey of local authorities in the south west and selected others from England conducted in 2007 and presents interim conclusions.

Qualitative methods for ecologists and conservation scientists

© 2018 The Authors. Methods in Ecology and Evolution

Real-time consequences of riparian cattle trampling for mobilization of sediment, nutrients and bacteria in a British lowland river

ABSTRACT Rivers and their catchments support multiple human needs, necessitating integrated management of land and water resources. Agricultural land use, specifically the impacts of riparian cattle trampling, potentially significantly contributes to damage to river systems. This study addresses a knowledge gap stemming from the paucity of prior research correlating generation of pollutants with cattle activity locally and in ‘real time’. Turbidity, soluble reactive phosphorus and faecal coliforms were analysed at upstream control and downstream impact sites correlated with cattle activity over a 65 m river margin throughout a two-month summer period. Riparian cattle trampling impacted water quality, specifically turbidity and faecal coliform levels. Average turbidity increased by more than 90% between upstream and downstream sites during cattle activity, whilst average faecal coliform counts almost doubled. Findings for phosphorus concentrations were less conclusive, perhaps due to filtration of suspended sediment-bound phosphorus prior to analysis. Illustrative cost–benefit assessment of potential buffer zone installation to exclude cattle from the river margin at the study site, based on values transferred from a relevant published study, found that investment in a buffer zone would achieve a benefit-to-cost ratio of approximately 38:1 with a distribution of broad societal benefits to the farmer, local people and wider publics.