Understanding river pollution and its impacts on the past, present and future health of marine ecosystems

Research Excellence and Impact
Inputs of pollutants (nutrients, heavy metals) from terrestrial waterborne sources to the marine environment are a key anthropogenic pressure on the health of the marine environment whose impact is quantified as part of both UK and international marine assessments . Pollution, particularly from sewage, of the UK's rivers and coastal waters is currently gaining public attention, with Government under pressure to take action. Internationally, the OSPAR Convention for the Protection of the North-East Atlantic's 2030 strategy requires development of formal reduction levels for nutrient inputs in the context of climate change, and a new riverine inputs indicator is being deployed under the UN Sustainable Development Goals. Informed policymaking to improve coastal water quality requires an improved process-focused understanding of historical pollution inputs; UK-wide riverine nutrient inputs were last reported in the peer-reviewed literature in 2001. In the last 20 years there have been significant changes in UK inputs, some linked to improvements in pollution management, alongside significant changes in input monitoring whose impact on the resulting dataset is not yet fully understood.

Overarching Objective
To demonstrate how and why the UK's terrestrial pollution inputs to coastal waters changed in the past 30 years using new targeted high-resolution riverine and coastal water quality measurements alongside existing long-term monitoring datasets, linking waterborne inputs directly to impacts on the health of the marine environment.

Research Aims and Questions
(1) To accurately estimate pollution from downstream of riverine monitoring points from diffuse sources which, to date, have been omitted from UK assessments of inputs. What impact do these sources have compared to reported riverine and direct discharges?
(2) To develop an understanding of how different chemical species (e.g., dissolved, particulate, organic, inorganic) effect the marine environment. Which species are the most important, e.g., for coastal phytoplankton growth, and have these been appropriately captured in historical monitoring?
(3) To propose how the input monitoring programme can be future-proofed to climate change. How to establish confidence that expected/projected climate impacts are captured and can be differentiated from management measures and other changes?

Student Role and Development
The student will perform the detailed spatial timeseries analysis of the UK's inputs monitoring timeseries which is lacking from its highly aggregated presentation in marine assessments, supported by the UK's OSPAR INPUT Technical Lead. This will inform selection of case studies where hypotheses will be tested by new focused high spatial and temporal resolution sampling, providing practical hands-on sample collection and analysis skills. An interdisciplinary catchment-to-coast approach will be applied, integrating terrestrial catchment-focused information into coastal and marine assessment and policymaking. With a supervisory team providing both terrestrial and marine expertise, the student will be ideally placed to work across this traditional land-sea specialism divide. Through Cefas and EA supervisors embedded in the UK's marine policy and assessment processes at both the national and international level, the student will have the opportunity to feed their results directly into policy conversations.