AUFRANDE
Understanding the causes and predicting the decline of seagrass beds on Reunion Island using a hybrid modelling approach
2025-2028
Seagrasses form coastal habitats of high ecological value as they are ecosystem engineers, supporting high levels of biodiversity, improving water quality, protecting coastlines from erosion, storms and floods, and trapping carbon. In tropical regions, anthropogenic pressures are very high, seagrass decline is high and biodiversity is greatly threatened.
On Reunion Island, seagrasses began to decline in 2017 and have almost disappeared today, suggesting that beyond a certain threshold of fragmentation, the meadow can no longer regenerate.
The project aims to analyse the seagrass fragmentation dynamics over decades in a tropical environment and explore the causes of meadow fragmentation using an existing time and space seagrass dynamics model coupling a process-based hydrodynamic-sediment transport model at 10-m resolution with a probabilistic seagrass growth model. Fragmentation thresholds beyond which the meadow is no longer resilient could be identified in this highly anthropogenic tropical system experiencing climate change.
The output of the study will be a conceptual model describing the seagrass dynamics on Reunion Island highlighting the processes initiating and maintaining the ongoing decline of seagrass. This will help to inform the rehabilitation of seagrass beds in the lagoon.
Scientific contacts :
Héloïse Muller (DHYSED), Romaric Verney (DHYSED), Paul Wu (QUT, Australie)
Collaborations :
Reunion island marine reserve
Financing :
Programme AUFRANDE, PEPR BRIDGES