Reconstruction of Coral Reef Ecosystem Health in Lagoon Cay, Belize Using Invertebrate Assemblages in a Reef Matrix Core

Coral abundance is declining worldwide due to anthropogenic factors such as overfishing, agricultural advancements, and human driven climate change. While we have abundant data on reef coverage from underwater surveys completed in recent decades, there remains significant gaps in reef ecosystem data predating the 1970s. Reef matrix cores can help fill this knowledge gap by providing long-term records of reef community change prior to global-scale anthropogenic disturbance. We analyzed subfossil invertebrate assemblages preserved in lagoonal reef-matrix cores from Lagoon Cay, Belize. Bivalves, gastropods, coral, and echinoderm spines were sorted from sieve residue at 5-cm increments. Bivalves and gastropods were identified and counted. Echinoderm spines and coral were identified and weighed to obtain proportional abundance. All were identified to the lowest taxonomic level, typically to genus. Observed in this core is pre-colonial stability amongst the represented taxa. These stability patterns signal the abundance of available hard substrate (i.e., reef building corals). Herbivorous gastropods dominated the gastropod assemblage throughout the core, which is likely due to the abundance of benthic algae accessible to graze on over hard substrate. Despite its role as a keystone herbivore within Caribbean reefs, Diadema antillarum was not the dominant urchin anywhere in the core. Instead, Echinometra spp., the dominant urchin on these reefs today, was the most abundant urchin in all sections. The trends in available taxa show a healthy reef in the represented time. This contrasts other Caribbean cores as well as other cores from Belize. This could be due to the core not extending far enough into the present with the most recent date being 1867. Investigating long-term changes in coral reef invertebrate communities can reveal the ecosystem-level effects of recent declines in Caribbean reef-building corals.The Smithsonian MuseumUniversity of California San DiegoThe Ohio State University School of Earth Science’s Friends of Orton HallNo embargoAcademic Major: Earth Science