Development of the Coastal Environmental Sustainability Index (CESI) as a management tool for touristic and recreational beaches

Beaches provide essential ecosystem services to both residents and visitors. In particular, sun-and-beach tourism supports many coastal economies worldwide. However, it leads to significant environmental impacts, jeopardizing the long-term sustainability of beach socio-ecosystems. Urban tourist beaches face a dual challenge: balancing the provision of recreational services with the preservation of their landscapes and bathing quality. To address this challenge, this work aimed to generate an index to evaluate the environmental sustainability of urban beaches, concerning their environmental state, relative level of urbanization, and recreational potential. Three initial indexes were proposed based on quali-quantitative parameters, from which the final Coastal Environmental Sustainability Index (CESI) was constructed. To evaluate its potential application, the CESI was tested on eleven southeastern Atlantic beaches. The CESI assessment showed that it can be applied to a wide range of environmental and urban settings. The results enabled evidence of the current level of compensation between natural and economic capital flows in urban beaches. The proposed method allows for low-cost and reproducible estimates based on empirical data. It contributes a simple, applicable, and reproducible but suitable framework for assessing the beach's environmental state from which comprehensive management strategies can emerge.