Beachrock and erosion threaten tropical island shoreline stability and development.
Shoreline change on Seven Mile Beach, Grand Cayman, is influenced by beachrock and shore protection structures. Historical analysis shows erosion on the edges and growth in the middle of the beach without beachrock. Exposed beachrock leads to persistent erosion, creating a feedback loop with waves. A Category 5 Hurricane temporarily reversed long-term shoreline patterns but they returned within 2 years. Erosion and reduced sediment supply are causing beachridge cannibalization and emergence of buried beachrock. Coastal structures and erosion measures impact shoreline change, with recommendations for coastal management including setback lines.