Cornwall College University Centre
St Austell Bay Rivers: Seagrass Nutrient Study
"The interest in the dissemination of this research has been far greater than I anticipated. Local communities showed a strong enthusiasm for understanding the state of their seagrass, reflecting a growing trend of awareness and concern within St Austell Bay"
In 2025, Justin Hean and the team from Cornwall College University Centre studied one of the UK’s largest seagrass meadows in St Austell Bay, Cornwall. The project aimed to understand how nutrient pollution from rivers and streams affects seagrass health and to provide a baseline for future conservation efforts.
Funding from Sea-Changers covered the costs of isotopic analysis for 28 seagrass samples, providing detailed information on carbon, nitrogen, and their isotopes. This revealed that even areas previously thought to be cleaner were experiencing nutrient enrichment, mostly from sewage and agricultural runoff. The results highlighted the importance of considering the whole bay rather than focusing only on obvious discharge points.
The project produced data that will inform local conservation management, including engagement with the Cornwall Wildlife Trust, local councils, and individual landowners. Public engagement has also been strong, with presentations planned for Friends of Par Beach and the UK Seagrass Symposium 2025. The findings contribute to wider UK research on seagrass, while inspiring local communities and future researchers.
Sea-Changers' grant:
£374
