Multi-decadal shoreline change in coastal natural world heritage sites – a global assessment

A global assessment of shoreline change in coastal Natural World Heritage Sites (NWHS) reveals that 14% of these sites exhibit significant and rapid erosion or accretion, with mean rates of -3.4 meters per year and +3.5 meters per year, respectively. These extreme changes are primarily driven by sediment redistribution influenced by natural coastal morphodynamics—such as the opening of inlets (e.g., Río Plátano Biosphere Reserve) or alongshore sediment transport gradients—and human interventions like sand nourishment or river damming. The study, utilizing satellite-derived shoreline datasets from 1984 to 2016, found that low-lying vegetated tidal systems and deltas at the mouths of large rivers are particularly vulnerable. While relative sea-level rise correlates with shoreline retreat in some regions (e.g., Wadden Sea), its global impact on NWHS remains uncertain but is a growing concern. The findings underscore the need for future management plans to account for these dynamics, which threaten heritage values and coastal communities.

Sabour, S., Brown, S., Nicholls, R. J., Haigh, I. D., & Luijendijk, A. P. (2020). Multi-decadal shoreline change in coastal natural world heritage sites – a global assessment. Environmental Research Letters, 15(10), 104047. https://doi.org/10.1088/1748-9326/ab968f