January 2019 : South Caicos
Dying corals were first observed in the Admiral Cockburn Land and Sea Park in January 2019 by staff at the School for Field Studies (SFS). By March it was realized that stony coral tissue loss disease (SCTLD) was responsible for this unusual mortality. Initial assessments of the damage, that began in April 2019 (when up to 24 species were reported affected) with visual belt transects and roving photo surveys, were continued in June and October. Several affected corals were videographed at different times in April to create digital 3-D models of their surfaces to determine the rates at which the disease was spreading.
Sixty healthy corals (at 10, 20 and 30 m) were tagged in October and will be inspected for signs of infection in November. Visual transect surveys and digital 3-D modeling of newly diseased corals will be repeated at this time. On South Caicos, Agaricia agaricites and Dichocoenia stokesii are the most common of the species that are susceptible to SCTLD, although a higher percentage of Orbicella faveolata are affected by the disease.
April 2019 : West Caicos – Providenciales and Pine Cay
A maze coral (Meandrina meandrites) with SCTLD to show patterns of tissue loss, Spanish Anchor dive site, West Caicos, July 9, 2019. Photo: © Alizee Zimmerman.
Corals of species susceptible to SCTLD were becoming sick at Spanish Anchor near the southwestern tip of the island on April 17, and an outbreak of SCTLD was apparent here by May 23 (A. Zimmermann, pers. comm.). By mid-August, the disease had spread north (downcurrent) to NW Point and Grace Bay on northern coast of Providenciales. Roving diver surveys are being used to follow the progression of SCTLD by the staff at the Turks and Caicos Reef Fund (TCRF) and Department of Environment and Coastal Resources (DECR) at three westerly oriented sites (two off West Caicos, one to its north in Sandbore Channel) and two that are northerly oriented (one each off Providenciales and Pine Cay). Thirty corals (or coral groups) have also been marked for ongoing photo monitoring of their health at each of the two northern sites.
In the Caicos, the disease has been seen most frequently in Agaricia agaricites, Colpophyllia natans, Dendrogyra cylindrus, Dichocoenia stokesii, Diploria labyrinthiformis, Meandrina meandrites, Montastraea cavernosa, Orbicella annularis, O. faveolata, Siderastrea siderea,and Stephanocoenia intersepta. Other affected species include Agaricia tenuifolia, Eusmilia fastigiata, Isophyllia sinuosa, Mycetophyllia lamarckiana, Orbicella franksi, Siderastrea radians and Solenastrea bournoni.
SCTLD has not yet been reported in Grand Turk or elsewhere on the Turks Bank.
A gray angelfish “inspects” the newly dead area of a great star coral (Montastraea cavernosa) with SCTLD, Gullies dive site, West Caicos, September 4, 2019. Photo: © Alizee Zimmerman.
Educational outreach about SCTLD and how to minimize its spread has been given to dive and snorkel boat operators by TCRF staff in Providenciales and to dive shops by DECR staff in Grand Turk. Members of the Hotel and Tourism Association have been informed, and are contributing funding to support the TCRF/DECR disease monitoring effort.
Articles published in The Turks and Caicos Weekly News :
- Killer coral disease hits TCI -Dreaded stony coral tissue loss disease sighted off West Caicos, June 10, 2019
- Coral disease may be controlled but not defeated, experts say, June 17, 2019
- Fears intensify for TCI’s precious reefs, July 29, 2019
- Efforts to stem lethal coral disease soon underway, Aug 26, 2019
Times of the Island Contributed articles by SFS and TCRF staff :
With contributions for South Caicos from Drs. Heidi Heitler and Franziska Elmer (School for Field Studies), and for West Caicos–Providenciales and Pine Cay from Alizee Zimmermann (Turks and Caicos Reef Fund).