Management responses in Belize and Honduras, as stony coral tissue loss disease expands its prevalence in the Mesoamerican reef

Abstract

Stony Coral Tissue Loss Disease (SCTLD) has affected Caribbean coral reef colonies since it was first detected in Florida in 2014. Its rapid spread and virulent nature are a major concern to coastal nations in the Caribbean Sea. Belize and Honduras have approached their management and strategies in somewhat different ways, but with the same goal of evaluating and controlling the spread and reducing mortality rates of their coral colonies. They both used amoxicillin trihydrate powder with Coral Ointment Base2B which proved effective in halting the spread of the disease and lowered mortality rates in treated corals. In addition to treatment, both countries have continued to monitor the extent of the disease, entering the data into the collaborative disease tracker platform on AGRRA.org. Between October 2020 and November 2021, a total of 14,495 corals from 29 species were assessed at sites in Belize and Honduras that were affected by SCTLD. The overall prevalence (all coral species) of SCTLD at these sites was 14%. Three species (Meandrina meandrites, Dendrogyra clyindrus and Dichocoenia stokesi) were in the top affected species in both countries, with 42%, 38% and 32% SCTLD prevalence, respectively. The sharing of information allowed Belize and Honduras to be relatively prepared for the onset of SCTLD in their waters through a series of monitoring and intervention actions. Although the treatment has proved to be somewhat effective, it is time and labor intensive. Reducing other well-known anthropogenic including sewage and dredging, is key to supporting coral reef health and resiliency.

Broadscale coral disease interventions elicit efficiencies in endemic disease response

“…Returning to previous reef areas of higher treatment density did not yield the same treatment density, suggesting that disease prevalence did not stay consistently high over time. These results align with Forrester et al (2022) who found reduced SCTLD prevalence, lesion severity, and mortality at treatment sites in the British Virgin Islands. Although only few individuals at each treatment site received treatment, such sites exhibited community-wide benefits such as decreased disease prevalence over time and an increase in cover of some highly susceptible species.…”

“…Although only few individuals at each treatment site received treatment, such sites exhibited community-wide benefits such as decreased disease prevalence over time and an increase in cover of some highly susceptible species. Due to the lack of control sites within our study, we cannot explicitly conclude sites with treated corals exhibited similar patterns to Forrester et al (2022), but the decrease in disease prevalence throughout the study suggests this as a plausible explanation.…”

Interplay of management and environmental drivers shifts size structure of reef fish communities

“…mortality on reefs in the northern MAR(Alvarez-Filip et al, 2019;Estrada-Saldívar et al, 2020) and has recently been observed in Belize and Honduras (LeeHing et al, 2022). Whether this disease will impact hard corals within the MPAs surveyed in this study, and what the consequences might be for the fish communities, remains to be seen.…”

“…Given that juvenile fish biomass responded strongly to the availability of structurally complex hard coral habitat, corroborating previous findings (Alvarez‐Filip et al., 2011), it is concerning that coral habitat is increasingly threatened by climate change, human activities, and now the emergence of stony coral tissue loss disease (SCTLD). The spread of SCTLD has led to rapid and significant mortality on reefs in the northern MAR (Alvarez‐Filip et al., 2019; Estrada‐Saldívar et al., 2020) and has recently been observed in Belize and Honduras (Lee Hing et al., 2022). Whether this disease will impact hard corals within the MPAs surveyed in this study, and what the consequences might be for the fish communities, remains to be seen.…”

Mixtures of genotypes increase disease resistance in a coral nursery

“…More recently, stony coral tissue loss disease (SCTLD) threatens the existence of numerous other reef-building corals around the Caribbean 10 , 13 , 14 . While the etiology of SCTLD is still unknown, the application of antibiotics has been effective at a colony scale 15 – 20 , but cannot keep pace with continued infections and reinfections on the reef scale. Marked coral population declines and localized extinction have led to increased global efforts to restore degraded tropical reefs that often involve coral nurseries 21 .…”