Excessive sedimentation is known to be a key cause of ecological damage and deterioration to aquatic ecosystems. Each year, Yorkshire Water removes around 30,000 tons of sediment from rivers prior to treatment and subsequent supply of drinking water, costing an estimated £350,000 per year. Invasive Non Native Species (INNS) threaten aquatic ecosystems (Dudgeon et al., 2006), drinking water supplies and cost the water industry around £8m per year to remove (UKWIR, 2016). Furthermore, INNS such as Himalayan Balsam (Greenwood & Kuhn, 2014) and Signal Crayfish (Harvey et al., 2014) may drive increased sedimentation in rivers (Greenwood & Kuhn, 2014) resulting in increased operational costs and ecological deterioration under EU Water Framework Directive (WFD) status.
The rate of spread of INNS is increasing, and eradication of established invaders is highly unlikely (Simberloff et al., 2013). Therefore, measures which limit or mitigate sedimentation impacts are required. This research will investigate INNS related sedimentation in the Yorkshire Derwent catchment to identify methods and management options to reduce sediment levels and biodiversity loss whilst increasing the amenity value and broader environmental benefits such as ecological resilience, flood risk and water quality.
The successful candidate will have the opportunity to carry out controlled field (before-after-control-impact) experiments to assess the impact of INNS on river sedimentation, including the trial of various river management and survey techniques including habitat restoration, riverbank stabilisation and laboratory experiments. Using this approach, the student will be able to address the following research questions; (1) what effect do INNS have on the sediment load in the Derwent catchment?; (2) which management techniques offer the best solution to reducing sediment loads whilst increasing biodiversity and amenity value?; (3) how can these techniques be applied at a catchment scale?
Potential for research impact
The student will benefit from extensive training and work placements with Yorkshire Water and collaboration with river managers including the Environment Agency, Environmental NGOs and local farmers. The outcomes of the research will allow the identification of measures that can alleviate INNS related sedimentation and prevent deterioration of riparian banks and instream habitat which result in WFD failure to meet good ecological status or potential. Through existing collaborations across Catchment Partnerships and water industry networks, the results from this work will be applied across other catchments and by other water companies, and therefore has the opportunity to impact the future management of UK rivers.