Effects of the Stony Coral Tissue Loss Disease Outbreak on Coral Communities and the Benthic Composition of Cozumel Reefs

Abstract

In the Caribbean, disease outbreaks have emerged as significant drivers of coral mortality. Stony Coral Tissue Loss Disease (SCTLD) is a novel white plague-type disease that was first reported off the Florida coast in 2014. This disease affects >20 coral species and is spreading rapidly throughout the Caribbean. In December 2018, SCTLD reached southwestern (SW) Cozumel, one of the healthiest reef systems in the Caribbean. In this study, we integrate data from multiple survey protocols conducted between July 2018 and April 2020 to track the progression of the outbreak in SW Cozumel and to quantify the impacts of SCTLD on coral communities and the benthic composition of reefs. Given that the SCTLD outbreak coincided with a period of prolonged thermal stress that concluded in widespread coral bleaching in autumn 2019, we also investigated whether this event further exacerbated coral mortality. Our findings show that SCTLD spread throughout SW Cozumel in only 2 months and reached a peak after only 5 months. By the summer of 2019, most of the afflicted corals were already dead. Species of the families Meandrinidae, Faviinae, and Montastraeidae showed 33–95% mortality. The widespread coral die-off caused an overall loss of 46% in coral cover followed by a rapid increase of algae cover across all surveyed reefs that persisted until at least April 2020. In November 2019, more than 15% of surveyed coral colonies were bleached. However, we did not find that bleaching further increased coral mortality at either the colony or the community level, which suggests that the coral communities were able to recover from this event despite still being affected by the disease. In conclusion, SCTLD is radically changing the ecology of coral reefs by decimating the populations of several key reef-builders and reconfiguring the benthic assemblages. The actions needed to restore coral populations have to be accompanied by stringent controls related to the effects of climate change, coastal development, and wastewater treatment to improve coral conditions and ecosystem resilience.

Similarities and Differences Between Two Deadly Caribbean Coral Diseases: White Plague and Stony Coral Tissue Loss Disease

“…Since first described in 2014, SCTLD spread across the United States Caribbean region in 4 years, with cases reported across 18 locations, specifically in Jamaica (late 2017, Lang, personal communication) and later in Mexico, Saint Maarten, the United States Caribbean and United States Virgin Islands (Brandt et al, 2021), the Dominican Republic (Irazabal and Rodriguez, 2019), Turks and Caicos Islands, Belize, Saint Eustatius, and Puerto Rico, The Bahamas, the Cayman Islands, Guadeloupe, St. Lucia and Honduras (Kramer et al, 2020) 1 . The most deadly events have been reported for Mexico (Thome et al, 2021), the Mesoamerican Reef System, The USVI, and the Flroida Reef Tract (i.e., 40 to 50% live coral loss) with prevalence levels similar to the ones reported for WPD-II and in some cases, much higher 1 https://www.agrra.org/wp-content/uploads/2021/02/MPAConnect-SCTLDmonitoring-roving-diver-surveys-JLang-Jan-2021.pdf than disease baseline levels expected for Caribbean reefs (Ruiz-Moreno et al, 2012;Aeby et al, 2019;Alvarez-Filip et al, 2019;Precht, 2019;Weil et al, 2019;Neely and Lewis, 2020;Brandt et al, 2021;Estrada-Saldívar et al, 2021). This is likely because of the more persistent nature of SCTLD.…”

“…Common features of the macroscopic lesions of SCTLD and WPD as well as many other diseases are the rapid loss of tissues, which leaves denuded skeleton quickly colonized by opportunistic organisms (Figure 2). However, lesions of SCTD are reported to advance faster than WPD II (Aeby et al, 2019;Alvarez-Filip et al, 2019;Estrada-Saldívar et al, 2021), just as this disease was reported to move faster than WPD I. Another sign that has been regarded as unique for SCTLD, is the bleaching front and/or spots (Aeby et al, 2019;Landsberg et al, 2020; Figures 2-4), nevertheless, the bleaching front was noticed in some cases in corals affected by WPD II and WBD (Pantos et al, 2003;Bythell et al, 2004).…”

“…While there is a strong overlapping on host ranges, susceptibility to both diseases is slightly different, with Orbicella spp. being more susceptible to WPD-II (Nugues, 2002;Sutherland et al, 2004;Weil, 2004;Weil and Cróquer, 2009;Richardson, 2016), and Dendrogyra cylindrus, Meandrina ssp., M. cavernosa, S. siderea, and E. fastigiata being particularly prone to get SCTLD in the field (Walton et al, 2018;Aeby et al, 2019;Alvarez-Filip et al, 2019;Kramer et al, 2020;Brandt et al, 2021;Costa et al, 2021;Estrada-Saldívar et al, 2021). Furthermore, a recent study indicates that Orbicella annularis, C. natans and S. siderea are highly susceptible to SCTLD in the laboratory (Meiling et al, 2021).…”

Metabolomics of Healthy and Stony Coral Tissue Loss Disease Affected Montastraea cavernosa Corals

“…Caribbean coral reefs are experiencing an ongoing outbreak of a tissue loss disease named stony coral tissue loss disease (SCTLD), which first appeared along the Florida Reef Tract in 2014 (Miller et al, 2016;Walton et al, 2018;Muller et al, 2020) and continues to spread throughout various countries in the Caribbean (Precht et al, 2016;Alvarez-Filip et al, 2019;Kramer et al, 2020;Muller et al, 2020;Estrada-Saldívar et al, 2021;Heres et al, 2021;Thome et al, 2021). At least 24 different coral species are susceptible to SCTLD, however, intraand interspecific differences have been observed (Precht et al, 2016;Aeby et al, 2019;Ushijima et al, 2020;Walker et al, 2020;Meiling et al, 2021).…”

Metabolomics of healthy and stony coral tissue loss disease affected Montastraea cavernosa corals

“…Caribbean coral reefs are experiencing an ongoing outbreak of a tissue loss disease named stony coral tissue loss disease (SCTLD), which first appeared along the Florida Reef Tract in 2014 (Miller et al, 2016;Walton et al, 2018;Muller et al, 2020) and continues to spread throughout various countries in the Caribbean (Precht et al, 2016;Alvarez-Filip et al, 2019;Kramer et al, 2020;Muller et al, 2020;Estrada-Saldívar et al, 2021;Heres et al, 2021;Thome et al, 2021). At least 24 different coral species are susceptible to SCTLD, however, intra-and interspecific differences have been observed (Precht et al, 2016;Aeby et al, 2019;Ushijima et al, 2020;Walker et al, 2020;Meiling et al, 2021).…”