A rapid spread of the Stony Coral Tissue Loss Disease outbreak in the Mexican Caribbean

Abstract

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.

Diversity and Disease: The Effects of Coral Diversity on Prevalence and Impacts of Stony Coral Tissue Loss Disease in Saint Thomas, U.S. Virgin Islands

“…Devastating impacts of coral diseases on Caribbean reef ecosystems are well documented and have led to drastic alterations in community composition and diversity within reef communities (Aronson and Precht, 2001;Ward et al, 2006;Miller et al, 2009;Pollock et al, 2011;Alvarez-Filip et al, 2019). The Caribbean region has been identified as a "hotspot" for coral disease due to the high number of diseases and high frequency of outbreaks (Sutherland et al, 2004;Weil and Rogers, 2011;Muller and van Woesik, 2012).…”

“…A 3-year (2005-2007) study by Ruiz-Moreno et al (2012) found that 20% of Caribbean reefs had disease prevalence of over 10%. With a high number of disease events, reefs within the Caribbean have seen a decline in living corals from 50 to 80% (Aronson and Precht, 2001;Jackson et al, 2014;Alvarez-Filip et al, 2019). However, disease events can be especially destructive when it targets critical reef-building species.…”

“…In January 2018, SCTLD was reported in the Gulf of Mexico and has since rapidly spread across the Caribbean (Alvarez-Filip et al, 2019;Kramer et al, 2020). Although not confirmed, evidence suggests that SCTLD first arrived in St. Thomas via ballast water from ships and that its subsequent spread is associated with local currents and tidal patterns (Dahlgren, 2020;Staletovich, 2020).…”

“…However, species susceptibility could exhibit spatial differences that may vary regionally (SCTLD Case Definition, 2018;Aeby et al, 2019). For example, a study by the Florida Keys National Marine Sanctuary (SCTLD Case Definition, 2018) determined that Agaaricia agaricites and Porites astreoides were intermediately susceptible to SCTLD based on mortality rate over time, however, Alvarez-Filip et al (2019) determined these species had low susceptibility based on disease prevalence over time in Mexico. Due to the severity of this disease, it is critical to know the susceptibility of species in each region of the Caribbean to better understand the impacts of SCTLD.…”

Effects of surface geometry on light exposure, photoacclimation and photosynthetic energy acquisition in zooxanthellate corals

“…As depth increases, these low-productivity areas with greater inclination angles are predicted to experience negative photosynthetic energy balances constantly, becoming increasingly less productive and more costly to maintain for the colony. The reduced productivity of colony surfaces with greater inclination angles, along with their partial dependence on other parts of the colony for energy, may partially explain their higher vulnerability to reduced light penetration associated with increased water turbidity [50] (Fig 6A), disease outbreaks such as the recent stony coral tissue loss disease [56], as well as environmental perturbations, including heat stress [57,58] In conclusion, this study highlights the significant influence of colony geometry on light availability, holobiont physiology and photosynthetic energy acquisition in zooxanthellate corals.…”