Declining Coral Skeletal Extension for Forereef Colonies of Siderastrea siderea on the Mesoamerican Barrier Reef System, Southern Belize

Forereef colonies of the slow-growing coral Siderastrea siderea on the Mesoamerican Barrier Reef System (MBRS) in southern Belize have shown a significant decline in annual skeletal extension since the early 1900s, shifting from the fastest to the slowest growth rates. This trend contrasts with relatively stable growth rates observed in backreef and nearshore colonies. The study analyzed 13 coral cores using X-ray imaging to estimate skeletal extension over a century, revealing declines of -0.020±0.005 mm/yr per year for forereef colonies, while backreef and nearshore colonies remained stable at 0.011±0.006 and -0.008±0.006 mm/yr per year, respectively. The findings suggest that forereef corals may be more susceptible to environmental stressors, possibly due to sediment plumes, nutrients, or pollution from neighboring watersheds. Ongoing research aims to reconstruct the history of these stressors to better predict and mitigate future impacts on coral reef ecosystems.

Castillo, K. D., Ries, J. B., & Weiss, J. M. (2011). Declining Coral Skeletal Extension for Forereef Colonies of Siderastrea siderea on the Mesoamerican Barrier Reef System, Southern Belize. PLoS ONE, 6(2), e14615. https://doi.org/10.1371/journal.pone.0014615