Dune ecosystems along the central Caribbean coast of Colombia: Evolution, human influences, and conservation challenges

The need for effective coastal dune management holds prominence due to its crucial role in preserving these unique and diverse ecosystems. Dunes have become a focal point in coastal management which reflects their extensive use of coastal areas. This study presents the first assessment of 19 dune systems along an 83 km reach on the Central Caribbean coast of Colombia. These dune systems are classified into four groups: i) Nebkha, ii) Foredunes, iii) Foredune and Blowout, and iv) Foredune, Blowout, and Transgressive dunes; each with unique characteristics and distribution patterns. Vegetation analysis identified 37 species, dominated by herbaceous forms. Four species were found to be new records for the Atl & PRIME;antico Department. Recent analysis of the evolution of these dune systems (1954-2022) revealed both accretion and erosion processes, with a dominant erosion trend in the more recent years. Anthropogenic interventions were minimal in most dune systems, but some exhibited varying levels of human-made structures. Litter was assessed across four grades (A-D), with no dune systems reaching Grade A, and most dunes exhibiting elevated to high-extreme levels of litter (Grades C and D). Coastal dunes are threatened by urbanization, sand mining, litter, invasive species, and beach driving, and lack of clear landward back-dune areas for migration due to sea-level rise and climate change. The results provide valuable information for coastal managers and planners to make informed decisions and conserve these unique ecosystems.