First Quantitative Assessment of Benthic and Fish Assemblages of Silver Bank, Dominican Republic

Caribbean coral reefs have been declining at unprecedented rates, with about 50% of live coral cover lost over the past 50 years. The description of benthic and associated fish assemblages in remote areas, supposedly less vulnerable to human stressors, is necessary to better understand the spatial extent of declining trends, and to target areas for special management and protection. We present results from an expedition to Silver Bank (SiBa), Dominican Republic, aimed at providing the first quantitative assessment of benthic and fish assemblages in the area in the last 20 years. In April 2022, seven sites were surveyed using the Global Coral Reef Monitoring Network and the Atlantic Gulf Rapid Reef Assessment protocols, to determine benthic composition, coral richness, prevalence of diseases, invertebrates, and fish assemblages. Contrary to our expectations, reefs showed severe signs of deterioration, with coral cover seldom exceeding 11% on average, with no more than 14 species (from the more than 60 for the Caribbean region). Turf algae and macroalgae dominated the reefs (37–90%). Coral disease prevalence did not exceed 1–2%, and no evidence of epizootic Stony Coral Tissue Loss Disease (SCTLD) was noticed. Clear signs of overfishing were recorded, with carnivores above 15 cm being scarce across all sites. Furthermore, herbivorous species also depicted sizes below 15 cm, with no more than eight species. Our results change the previous conception that reefs at Silver Bank are healthier than coastal reefs because they benefit from low anthropogenic pressures. This serves as an alert to local environmental authorities to improve surveillance and management actions to preserve this area.