Changes in Diversity, Density, and Biomass of Coral Reef Fishes in the Central Mexican Caribbean After the Construction of a Cruise Ship Pier

Decadal changes in the community structure of coral reef-associated fishes reflect prevailing poor environmental conditions. This study analyzed temporal shifts in fish communities (e.g., diversity, density, and biomass) recorded via SCUBA belt transects across coral reefs on the center–southern coast of Quintana Roo (eastern Yucatan Peninsula) in the Mexican Caribbean. Sites were initially investigated in 1995 and revisited in 2024 after the construction of a cruise ship pier, and we compared sites under different protection categories. Mean density and biomass decreased significantly over time, particularly at reef sites outside of a protected area in 1995. While species richness and density of commercially important fishes were higher in protected sites in 1995, parrotfishes (Scarinae) maintained stable density and biomass across both years and protection status. No significant differences were found in the biomass of other fishes (e.g., Haemulidae, Lutjanidae). Changes recorded may reflect historical fishing pressure, including poaching, but probably also pollution from intense growth of coastal tourism infrastructure in 2024, as well as damage from the beached Sargassum influx. Ultimately, the positive effect offered by protected areas is not enough to mitigate the local and regional environmental impacts on coral reefs. Our findings serve as a reference point where coastal development and climate change interact and affect coral reefs.