Deadly coral disease moves closer to Seven Mile Beach

DoE seeking dive volunteers

The red line in this map indicates where stony coral tissue loss disease has been found at sites along the North Wall, as of last week. - Image: DoE

The Department of Environment is appealing to divers to help monitor stony coral tissue loss disease which is spreading at about a mile a month towards Seven Mile Beach.

The disease was found in stony corals on Grand Cayman’s North Wall last summer and, in October, the DoE shut down 43 dive sites in the area in an attempt to combat its spread.

Tammi Warrender of the DoE told the Cayman Compass, “Unfortunately, SCTLD continues to spread along the reef and is getting closer to Seven Mile.”

The DoE has trained 30 divers to identify and manage the disease and there are 10 individuals who are dedicated to helping the department’s staff in the field every week, Wallander said, adding that new people are reaching out weekly to offer their assistance.

The DoE is currently looking for more volunteers to help out.

On Friday afternoon, 26 Feb., the DoE plans to hold an advisory briefing to update local water-sports operators on the situation.

This coral seen at Penny’s Arch in the Rum Point Channel is infected with Stony Coral Tissue Loss Disease. – Photo: DoE

Stony coral tissue loss disease, which has been found to affect more than 20 species of coral, first emerged on Florida’s reefs in 2014, and has since spread throughout most of the Caribbean region. It was first spotted in Cayman – at Penny’s Arch in the Rum Point channel – in June last year.

No sign of the highly contagious disease has been discovered on Little Cayman or Cayman Brac.

Stony coral tissue loss disease is believed to be caused by a pathogen. It attacks several types of stony coral, including primary reef-building coral species, like pillar, elliptical star, maze, brain and smooth flower coral.

The DoE had hoped that by shutting down dive sites on the North Wall, between Delia’s Delight at the eastern end and Conch Point Reef to the west, it could slow or stop the spread. However, recent observations have shown it progressing westward toward the Seven Mile Beach Marine Park.

According to the DoE, the “rapid progression of the disease over eight miles can be due to many factors”, including prevailing westerly water currents carrying the water-borne disease; corallivores – animals that use coral as a natural food source – possibly transferring it to healthy corals after feeding on infected corals; the direct contact of corals on the reef with each other; and the possible transfer of disease by humans conducting water-sports activities in an infected area, then moving to another site.

The sites on the North Wall were initially closed for three months in October, but in January the DoE advised that there had been a further two-mile spread of the disease westward, towards the Ghost Mountain dive site, near where the department had set up ‘coral firebreak’.

“At that time, SCTLD had not passed this boundary,” Warrender said in an email to water-sports operators on Sunday. “However, further monitoring and observations confirmed that the disease had progressed and infected the shallower reefs inside the North Sound, such as the Rum Point, Stingray City, and Vidal (Barcus) Cay areas.

“Due to the high prevalence of SCTLD and the increased likelihood of transmitting this infection to other sites, all SCUBA divers, snorkelers, and associated companies who access the North Sound were recommended by the DoE to implement a decontamination protocol  for all watersports gear immediately.”

She said that preliminary results had indicated that the DoE’s management interventions, including the coral firebreak, did slow the disease spread, which was progressing at more than one mile a month.

“Unfortunately, as of the 10th February 2021, the disease has now breached the coral firebreak,” she said.

Divers who are interested in volunteering to assist in the monitoring and control of the disease can contact Warrender at her email address, [email protected].

Water-sports operators who wish to attend Friday’s briefing are asked to email her with their name and the company they represent by 5pm on Thursday, 25 Feb. The meeting will not be available via Zoom, but Warrender said a recording would be shared afterwards.

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