Bacalar Chico Marine Reserve and National Park ('Bacalar Chico') forms part of the Belize Barrier Reef Reserve System, a UNESCO World Heritage Site. Coastal development, primarily the extensive clearing of mangrove forest, combined with direct over-extraction of marine resources and increased frequency of coral bleaching, diseases and hurricane events have caused dramatic decline in reef health, leading to its inclusion on the List of World Heritage Sites in Danger.
In March 2010, Blue Ventures embarked upon a long-term coral reef monitoring project within Bacalar Chico. In 2010, the majority of sites were found to be in poor condition, with no evidence of management-related difference between the four zones.
Results of monitoring in 2011 show continued decline in reef health, with the average Simplified Integrated Reef Health Index score of 2.16 in 2010 dropping to 1.90 in 2011. Average hard coral cover is 10%, and remains unchanged from 2010, with fleshy macroalgae and turf algae occupying the majority of the benthos. Commercial fish biomass is extremely low (536.89 ± 94.51 to 8996.70 ± 3010.30 g 100 m-2), with no observed differences between management zones.
Despite thriving herbivorous fish populations, some portions of the reef exhibit critically high levels of fleshy macroalgae, possibly linked to the loss of potential key phase-shift reversing species such as the rainbow parrotfish, Scarus guacamaia. Identification and intensification of conservation efforts for recovery of such species is of critical importance for any future recovery of reef health and function. As the threshold for phase-shift reversal from an algae-dominated reef to hard coral dominance is high and compounded by multiple factors, protection of reefs which have yet to undergo phase-shift should be prioritised. One section of the forereef system, located in the General Use Zone, has been identified as the healthiest site and maintaining reef health at this site is essential.