Evaluating the spread of stony coral tissue loss disease in the Bay Islands, Honduras

Photo: Fundación Albatros

Abstract

Scleractinian corals, considered key reef ecosystem engineers, have suffered irreparable damage over the last decades, with causes widely attributed directly and indirectly to increased human pressure on coral communities. Stony coral tissue loss disease (SCTLD), first detected in Florida in 2014, by early 2023 had spread to 26 jurisdictions in the wider Caribbean, causing severe effects on coral reefs. In January 2020, monitoring efforts to detect SCTLD began on the island of Roatan in Honduras. The disease was first reported in Flowers Bay, Roatan, in September 2020. Since then, dedicated collaborative efforts have been made to assess the severity of the disease, mitigate its effects, and raise coral reef conservation awareness. To track the progression of the outbreak, presence absence data were collected using the rover diver methodology. With at least 28 species affected, SCTLD has spread across the Bay Islands over a period of 13 months. Roatan and Utila have been the most impacted islands, with the disease encircling them rapidly at a rate of approximately 155 m/day. The spread of SCTLD was overall rapid, but geographical patterns were detected in Roatan, where it showed faster progression on the windward side than on the leeward side. Further research is required to explore whether these disparities are related to marine traffic, water quality, currents, or a combination of multiple factors. Our findings shed new knowledge on the spread of SCTLD in Honduras, which can provide insights for other Caribbean nations whose economies are also

Introduction

Scleractinian species, commonly known as stony corals, have been impacted by an epizootic known as stony coral tissue loss disease (SCTLD) since September 2014 (Precht et al., 2016). This novel white plague-type disease is likely the most lethal coral disease currently known, causing devastating impacts to the Caribbean over the past seven years (Precht et al., 2016; Precht, 2021; Alvarez-Filip et al., 2022). Among these impacts, we can highlight the widespread mortality of up to 60% loss of living coral tissue and over 90% of pillar corals on the Florida Reef Tract (Walton et al., 2018; Neely et al., 2021), along with rapid disease spread throughout the 450-kilometer Mexican Caribbean coast, including a 46% loss of coral cover in Cozumel (Estrada-Saldı́var et al., 2021; Alvarez-Filip et al., 2022). Although the pathogen causing SCTLD remains elusive, recent studies have identified clear and consistent differences between healthy and diseased coral microbiomes suggesting that the disease may be caused by multiple factors, including bacteria belonging to specific groups, such as Vibrio, Arcobacter, Rhizobiaceae, or Rhodobacteraceae, and viral-like particles (Ushijima et al., 2020; Work et al., 2021; Becker et al., 2022; Huntley et al., 2022).

SCTLD affects around 30 species, including important reef- building species (e.g., Meandrina meandrites), species considered endangered by the global IUCN Red List (e.g., Dendrogyra cylindrus, Orbicella faveolata), and species listed as threatened under the U.S. Endangered Species Act (ESA) (e.g., the genus Orbicella) (U.S. Fish & Wildlife Service, 2014; Florida Coral Disease Response Research & Epidemiology Team, 2018; Cavada- Blanco et al., 2022). Characterized by its high virulence, the progression of lesions across a colony is rapid compared to other coral diseases, and in many cases, can result in full colony mortality (Aeby et al., 2019). Furthermore, SCTLD can have cascading effects throughout the ecosystem, causing a decline in coral cover and biodiversity (Walton et al., 2018; Costa et al., 2021; Heres et al., 2021).

Honduras is a key interconnectivity area in the Mesoamerican reef region (Chollett et al., 2017), boasting some of the highest coral cover in the region (McField et al., 2020). In Honduras, SCTLD was first reported on September 24th, 2020, in Flowers Bay, on the south shore of Roatan, Bay Islands and rapidly spread across the whole island. The Bay Islands, like many other locations in the Caribbean, strongly rely on healthy coral reefs, as their main source of income is tourism (Doiron and Weissenberger, 2014).

Given the urgency of this novel scenario, local non-government organizations (NGOs) have conducted rapid assessments using the rover diver methodology before and after the first report of SCTLD in the country. Additionally, intervention actions through topical antibiotic applications have also been led by NGOs in collaboration with government agencies and local businesses. Here we provide the first description to date of the spatial-temporal evolution of this novel disease across the Honduran Caribbean to provide insight for other areas that are still unscathed

Reference

Citation:
Truc M, Rivera A, Ochoa GM, Dueñas D, Guifarro Z, Brady G, Zu´ niga Z, Gutie´ rrez B, Chock C and Zaldivar L (2023) Evaluating the spread of stony coral tissue loss disease in the Bay Islands, Honduras. Front. Mar. Sci. 10:1197318. doi: 10.3389/fmars.2023.1197318.

Published date:
21 July 2023

Reference link:
https://www.frontiersin.org/articles/10.3389/fmars.2023.1197318/full

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