Extreme Climatic Events and Urbanization Impacts on Sandy Beach Ecosystems: A Field Experiment before and after Hurricane Lee

Climate change and human activities pose significant threats to coastal environments. Here, we investigated the effects of storm surges and coastal urbanization on Caribbean sandy beaches, focusing on changes in morphodynamics and population parameters of the Atlantic ghost crab Ocypode quadrata. We measured beach slope, sediment size, and ghost crab populations in non-urbanized and urbanized beaches in St. Thomas, U.S. Virgin Islands, before, three days after, and five weeks after storm surges from Hurricane Lee (September 2023). Storm surges impacted beach morphodynamics, causing some beaches to become steeper with coarser sediment in the short term. Ghost crab burrow density declined in every beach immediately after the hurricane, with reductions of 50–98%. However, number of burrows rebounded to pre-hurricane levels within five weeks. Mean burrow width increased while burrow depth decreased immediately post-hurricane, but also returned to pre-storm levels after five weeks. Additionally, ghost crab burrows were clustered in the upper beach zones immediately post-hurricane but redistributed across the shore gradient after five weeks. Our results show that sandy beach ecosystems are strongly affected by storm surges associated with extreme events; however, they display high resilience and may return to their previous state within a few weeks. Nevertheless, given that the frequency of intense tropical cyclones is expected to increase in the near future, more intense and frequent storms could result in chronic perturbations rather than isolated events, which may compromise sandy beaches’ long-term resilience and sustainability.