Habitat restoration of riverine phosphorus pollution on lowland UK agricultural peatland

Eutrophication of wetlands caused by urban, industrial, and agricultural runoff is a critical environmental issue, characterized by excessive plant and algal growth due to increased bioavailability of phosphorus (P). The Somerset Levels and Moors (SLMs), covering 70,000 ha, represent the largest area of lowland wet grassland and wetland habitat in the UK. River catchments in this region are heavily influenced by intensive agriculture and wastewater inputs, resulting in nutrient contamination of inflow waters that fail to meet the UK Government’s Water Framework Directive Good Status targets for P concentrations.
Established in 2013, the Somerset Catchment Partnership (SCP) unites central and local government, farmers, landowners, nature conservation organizations, and Wessex Water in a collaborative effort to restore the SLMs and achieve Good Ecological Status for the water bodies. Researchers at the University of Plymouth analysed macro-plant nutrient concentrations in ditches, dipwells, soil, sediment, and harvested plant biomass to assess the overall apportionment of P inputs, stores, fluxes, and loadings. The data reveal significant temporal and spatial variations in the concentrations of P and nitrogen (N) across the peat-rich soils.
Achieving consensus on land management solutions among multiple stakeholders has been challenging, necessitating a shared focus on climate resilience. Through collaboration, the SCP proposes that an altered hydrological regime and the harvesting of plant biomass in wet agricultural crops could mitigate further eutrophication. Additionally, researchers at the University of Plymouth have suggested that legacy P stored in the peat body could be mobilized by flooding and, over time, evacuated from the wetland.