Habitat suitability modelling for restoration of intertidal seagrass, Zostera noltei: A case study from the Greater Thames Estuary, UK

Abstract

Seagrasses are marine flowering plants that play crucial roles in blue carbon capture and coastal protection, as well as providing a critical feeding and nursery habitat for several species. However, the extent of seagrass meadows has drastically decreased around the UK coastline since the 1930s. As such, restoration of Zostera spp. seagrasses is a growing field for academics and practitioners, yet for Zostera noltei (dwarf eelgrass) in particular, restoration is hampered by knowledge of current distributions and where to restore. Habitat suitability modelling is a valuable tool for mapping and can be applied by practitioners at a site-specific scale to identify potential areas for restoration. Here we have created a Maximum Entropy (maxent) habitat suitability model to predict Z. noltei suitability in the Greater Thames Estuary based on seven environmental variables at a 10-m resolution within an intertidal boundary. Using areas of higher suitability to identify restoration potential, our results indicate 602.9 Ha of “good” suitable habitat for potential restoration around existing Z. noltei beds in the Thames, Medway and Swale Estuaries. Despite reasonable predictive accuracy, our model was limited by the availability, resolution and extent of important environmental variables such as sediment type. Nonetheless, we believe this is a valuable tool for practitioners in the initial stage of site selection at a local scale for Z. noltei restoration projects in the UK.