Environmental and anthropogenic drivers of contaminant influx and recirculation within freshwater systems.

With an increasing and ageing human population, pharmaceuticals and personal care products are produced in quantities nearing that of agrochemicals in scale, and are a major concern for human health. Discharge of pharmaceuticals and other chemical contaminants into the environment is one of the top issues of global conservation concern. The well-publicised near extinction of vultures in Asia due to diclofenac is a shocking example of the potential for harm. At the same time, the Environmental Quality Standards Directive and Water Framework Directive are driving the need to monitor biota for a range of priority substances, in order to assess levels of bio-magnification against standards designed to protect top predators and humans. The risks of bio-magnification should be seen in the context of likely changes in flow regime as a result of climate change, potentially driving the re-emergence of persistent contaminants such as PCBs that are stored in river sediments.

Currently, there is no widespread surveillance using freshwater sentinel species to assess emerging and re-emerging pollutants in the UK. The proposed scholarship will utilise a 25-year biobank of samples from an aquatic top predator, the otter, to investigate the frequency of detection and concentration of contaminants in otters, and the factors explaining variation in concentration, including biological (e.g. age, sex), spatial (e.g. proximity to large towns or sewage outflows), and temporal (e.g. association with increasing population, introduction of new chemicals). Collaborative partnerships with the Environment Agency, Natural Resources Wales, Centre for Ecology and Hydrology, and the National River Restoration Centre will ensure that the research effectively utilises existing surveillance data using water, sediment and lower trophic level biota monitoring regimes, and is relevant to current river management policy and practice.

Supervisory team: Dr E Chadwick, Dr F Hailer (Cardiff University); Prof R Shore (Centre for Ecology and Hydrology; Mr G Scholey (Environment Agency), Dr M Naura (River Restoration Centre).