Hydroscape:connectivity x stressor interactions in freshwater habitats

Lead Research Organisation: UK Ctr for Ecology & Hydrology fr 011219
Department Name: Water Resources (Lancaster)


All types of ecosystems exhibit connectivity at some level. However, connectivity is the quintessential property of aquatic systems. Connectivity matters in freshwaters because it is the means by which energy, materials, organisms and genetic resources move within and between hydrological units of the landscape (the 'hydroscape'). Hydrological connectivity is a particularly effective vector for multiple climatic, biological, chemical and physical stressors, although other forms of connectivity also link freshwater ecosystems. Our proposal addresses the fundamental question of how connectivity and stressors interact to determine biodiversity and ecosystem function in freshwaters.
Connectivity is multifaceted. It may be tangible - water moves downhill or over floodplains, or more subtle - terrestrial organic matter is incorporated into aquatic food webs. Animals and people naturally gravitate to freshwaters, thus providing additional dispersal vectors that can carry propagules to isolated sites. Connectivity may be passive or active and occurs across scales from the local to the global. Freshwater scientists recognise the fundamental role of connectivity in key paradigms such as the river continuum and flood pulse concepts. Land-water connectivity is also the founding principle behind catchment management. However, in reality, a long tradition of focusing on individual stressors, sites, taxonomic groups or habitats, has led to a highly disjointed view of the most intrinsically interconnected resource on the planet. While the need for an integrated approach to water management is universally acknowledged, an understanding of this most fundamental part of the infrastructure of freshwaters is lacking. This is a serious obstacle to meeting critical societal challenges, namely the maintenance of environmental sustainability in the face of multiplying human-induced stresses. Without a more integrated view of the freshwater landscape we struggle to answer basic questions. These include (i) how do organisms, nutrients and energy move naturally within and between landscapes? (ii) how is this basic template altered by different stressors, singly or in combination? (iii) how has widespread alteration of land cover and of the basic infrastructure of freshwaters that largely drives connectivity, redistributed pressures and modified their effects? (iv) how should reductions in stressors and changes to connectivity, that are now widely implemented, be prioritised when seeking to restore biodiversity and ecosystem function?
Our primary aims are to (1) determine how hydrological, spatial and biological connectivity impact on freshwater ecosystem structure and function in contrasting landscape types, and (2) use this understanding to forecast how freshwaters nationally will respond to (i) multiple, interacting pressures and (ii) management actions designed to reduce pressures and/or alter connectivity. We will achieve these aims by working at different spatial (landscape vs national) and temporal (sub-annual to decadal vs centennial) scales and using a combination of complementary well established and more novel molecular and stable isotope techniques. We will combine existing data sources (e.g. archived sediment cores, biological surveys and the millions of records held in national databases) with targeted sampling to maximise cost effectiveness and achieve a cross habitat and ecosystem wide reach.
Landscape scale thinking has become the new mantra of nature conservation and environmental bodies but the knowledge needed to ensure resilience to climate change and to underpin large scale conservation and restoration of aquatic landscapes is currently lacking. In this regard an understanding of how biodiversity and ecosystem function respond to the changing connectivity x stressors arena in freshwaters is critical. The outputs of the proposed research will deliver the integrated understanding of the hydroscape that is now required urgently.

Planned Impact

Our project bridges the gap between policy/management needs and state-of-the-art scientific research on the impacts of connectivity and multiple stressors on freshwater ecosystems. Outputs will provide the scientific evidence base and regulatory guidance needed to support the future sustainable management of freshwater landscapes at the local, national and international scale.
Our results will be useful to organisations engaged in waterbody restoration, biological conservation, the control of invasive species and diseases of wildlife and humans. At the national scale, these include organisations such as Scottish Natural Heritage, Natural England, Natural Resources Wales, Environment Agency, Scottish Environment Protection Agency, GB Non-Native Species Secretariat (NNSS), water utility companies, Wildlife Trusts, National Trust, Royal Society for the Protection of Birds, Plantlife, Buglife and the Rivers Trusts, with all of whom we have long established working relationships. More locally, organisations such as the Norfolk Ponds Project, Norfolk Biodiversity Information Service, Norfolk Wildlife Trust, Norfolk Biodiversity Information Service, Norfolk Farming & Wildlife Advisory Group, Natural England, Norfolk Rivers Trust, Broads Authority (a project partner), River Glaven Conservation Group, Cumbria Wildlife Trust, Eden Rivers Trust, Cumbria Biodiversity Data Centre, Forth Fisheries Trust, Scottish Wildlife Trust, Buglife Scotland, and many other similar organisations will also benefit from a better understanding of the links between connectivity and environmental stressors. In particular, we expect the results of this work to challenge the widely held belief that re-connecting isolated waterbodies and removing obstructions to fish migration are essential features of restoration projects. For example, in highly impacted systems, the adverse effect of the spread of invasive species and/or pollution caused by such re-connections may be greater than any benefit provided by links to refugia that can provide biological source material for recolonisation.
At the local level, our research outputs will help water managers improve biodiversity and habitat quality in a sustainable way. This will result in greater amenity value, with local businesses benefitting from more visitors and increased income, and increases in native biodiversity and water quality, which will help meet conservation objectives. Residents, visitors and local schools will gain a better understanding of the links between environmental stressors, connectivity, biodiversity and ecosystem function, especially through their combined impact on ecosystem service provision.
At the UK level, the results will provide environmental and conservation agencies (e.g. EA, SEPA, SNH, NRW, NE, Defra, RSPB) and policy makers with a better understanding of the processes involved in achieving the sustainable management of freshwaters and their catchments. In particular, appreciating that measures aimed at restoring a particular site may be impacted by connectivity across the freshwater landscape.
At an international level, the results are expected to inform the implementation of the 2020 EU Biodiversity Strategy, which aims to "halt the loss of biodiversity and ecosystem services". More specific international beneficiaries are the Directorate General for the Environment (DG Environment) in relation to informing Water Policy (Water Framework Directive) and Biodiversity Policy (Europe 2020). The proposed work on heavy metals pollution links directly to the EU Environmental Quality Standards Directive (2008/105/EC), which has the "aim of ensuring that existing levels of contamination in biota and sediments will not significantly increase....". We are also focusing on trace metals that are currently listed as 'Priority Substances' or 'Priority Hazardous Substances' under the Water Framework Directive.

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/N00597X/1 12/11/2015 30/11/2019 £747,249
NE/N00597X/2 Transfer NE/N00597X/1 01/12/2019 31/07/2021 £47,270
Description Connectivity, and the lack of it through the construction of dams and other barriers, is increasingly recognised as as a threat to fresh waters by restricting movements of native organisms (such as fish), affecting the spread of invasive species and affecting inputs of nutrients. Hydroscape has addressed these issues and provided scientific tools to help managers understand and make informed decisions to maximise ecological health.
Exploitation Route This work has highlighted the main consequences of altered connectivity and the main areas that could be managed to improve the health of fresh waters.
Sectors Environment

Description Connectivity metric sproduced by Hydroscape have been used to identify priority sites where a rare freshwater plant, Najas flexilis, is present and to prioritise sites where invasive non-native species are absent. This will be used to identify suitable sites for the introduction of this species to honour government commitments to protect and restore biodiversity in the UK.
First Year Of Impact 2020
Sector Environment
Description Collaboration with Natural England and local scientist 
Organisation Natural England
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Enhanced scientific knowledge of the operation of the Norfolk Broads to inform subsequent management decisions.
Collaborator Contribution Discussion with local staff member from Natural England in the Norfolk Broads who is happy to provide logistic support as is a local scientist- retired from Environment Agency but still very active.
Impact None yet.
Start Year 2016