Monitoring and Interventions Monitoring and Interventions of Stony Coral Tissue Loss Disease

In response to the disease outbreak, several groups are monitoring and trying new treatments and interventions to stop or slow the spread of stony coral tissue loss disease.

Monitoring in the Caribbean

SUBMIT A REPORT

To help track and better understand SCTLD in the Caribbean, we ask for your help in reporting observations by filling out the online survey form, which includes information on coral species affected, location, and photos. We are specifically interested in SCTLD reports or other unusually high reports of recent coral death.

If you see any instances of Stony Coral Tissue Loss Disease or suspected disease, please submit your findings and photos via one of the 3 survey forms below. There are 3 types of survey forms to make it easy to submit your data BUT you only need to fill out ONE of the forms per reef site. You can enter data by Scientific Coral Name, by Common Coral Group Name or by Roving Diver Survey.

For an overview of the survey tool, maps and directions on how to fill out the survey form, see this Coral Disease Tracking Tool.

MONITOR

Monitoring of SCTLD outbreaks will likely require initial rover diver surveys to establish presence/absence and spatial extent followed by surveys (e.g., belt transects, quadrats, mosaics) to document the spatial extent, coral species affected and mortality rates.

Monitoring Priorities

  • Priority coral disease response activities include:
    • Monitor highly susceptible species like Meandrina meandrites (maze coral), Dichocoenia stokesii (elliptical star coral), Dendrogyra cylindrus (pillar coral), and Colpophyllia natans (boulder brain coral).
  • • Monitor colonies of large, reef building coral species like Orbicella (mountainous star coral).
  • • Take photos of suspected diseased corals and submit your report using one of the survey links above with date and gps location.
  • • For confirmed disease occurrences, monitor every few days/weekly to track fate of colonies, rate of transmission and spatial extent.
  • • Evaluate and identify priority reef areas and priority coral colonies for intervention and treatments.

LEARN MORE

Given the potential for widespread areas to be affected, a multi-partner effort of managers, biologists and citizen scientists is suggested. To learn more about SCTLD, scientists and managers can train recreational snorkelers and divers to help properly identify SCTLD from other coral diseases and teach survey and investigation techniques.

Resources

Response & Interventions

FLORIDA RESPONSE ACTIVITIES

  • In Florida, priority coral disease response activities include:
  • • Coral disease investigation training on coral disease identification, ecology and investigation techniques.
  • • Coral disease surveys and fixed site monitoring to document the spatial extent, mortality rates and species-specific impacts.
  • • Strategic sampling and laboratory analysis to identify the presence of pathogens potentially responsible for the disease outbreak.
  • • Data management and epidemiological analysis to analyze relevant datasets and determine what factors may influence disease progression.
  • • Sampling plan and disease intervention workshops to determine priority data needs and potential management options to mitigate disease impacts.
  • • Intervention experiments and field trials to assess the effectiveness of treatment techniques and prevent the further spread of disease.
  • • Coral disease investigation training on coral disease identification, ecology and investigation techniques.
    • Coral disease surveys and fixed site monitoring to document the spatial extent, mortality rates and species-specific impacts.
    • Strategic sampling and laboratory analysis to identify the presence of pathogens potentially responsible for the disease outbreak.
    • Data management and epidemiological analysis to analyze relevant datasets and determine what factors may influence disease progression.
    • Sampling plan and disease intervention workshops to determine priority data needs and potential management options to mitigate disease impacts.
    • Intervention experiments and field trials to assess the effectiveness of treatment techniques and prevent the further spread of disease.

For more information on Florida’s monitoring and response efforts visit: www.floridadep.gov/fco/coral/content/florida-reef-tract-coral-disease-outbreak

FLORIDA INTERVENTION ACTIVITIES

In an effort to reduce the spread of disease and loss of live coral tissue, several laboratory and field trials have been done including topical applications of chlorine and amoxicillin, topical chlorinated epoxy, amputation of affected regions of diseased corals, and relocation of healthy regions of diseased corals. The results from efforts in Florida are summarized below and will be updated regularly. In Mexico, additional field intervention trials are ongoing and information will be posted when available.

In Situ Coral Disease Interventions in Florida

Summary of the Florida Department of Environmental Protection, Coral Reef Conservation Program, Final Report, Florida – FY 2018 In Situ Disease Intervention, Karen Neely and Emily Hower, Nova Southeastern University (2019)

  • – Amoxicillin treatments are much more effective than chlorinated treatments. This effectiveness is seen in summary analyses, but also when treatments among species (CNAT, OFAV, DLAB) are compared. But even then there was still up to 20% failure at 19 weeks.
  • – The CoreRx Base 2b showed lower subsequent encroachment of external lesions, suggesting a better dissemination to adjacent tissue (halo zone).
  • – Small patches (<5 cm, which might also represent newly diseased colonies) responded much better than large lesions.
  • – Response to treatments is species-specific. Brain corals (particularly DLAB) respond poorly, while OFAV responds well.
  • – Even the most effective treatments are acting only at the lesion level. New lesions continue to erupt and overtake treatments, leading to ongoing tissue loss as well as necessary frequent re-visitation to apply additional treatments. All corals needed more than one treatment.
  • – Schedules for re-treatment and monitoring vary based on species and perhaps disease status. Epidemic zones and highly susceptible species require more frequent monitoring to determine effectiveness, and more frequent re-treatments to catch new lesions or repair broken treatment lines.

Bottom line: focus resources on large colonies of Orbicella spp. as they’re the most important reef-builders, best known responders to amoxicillin and also likely to be the largest local reservoirs of the pathogen.

Above photos show coral with SCTLD (top) and treatment efforts by researchers in Mexico (bottom) (Photos provided by M. Soto, HRI).

Suggestions for future work:

  • – Address whether species like OFAV that respond well to treatment would also respond well in epidemic or invasion zones would prioritize these corals before they experience significant tissue loss, and while lesions are still small might better respond to treatments.
  • – Further comparisons of amoxicillin treatments with and without trenching or the application of clay to cover the treatments would elucidate the effectiveness of these additional measures.
  • – A high priority research topic should be to address intervention at the colony or reef level, and management questions relating to this should be considered well in advance. Potential options may include antibiotic dosing by bagging or medicated feed, and could include probiotic application or phage therapy.
  • – Reef-scale intervention may also be considered on small patch reefs by treating all lesions within an isolated region to determine whether the elimination of lesions in such an environment could have reef-scale consequences.

Walker, B and A. Brunelle. 2018. Southeast Florida large (>2 m) diseased coral colony intervention summary report. Florida DEP & FWC. Miami, FL. Pp. 1-164.

Report Summary

“The purpose of this project is to perform disease intervention on previously-identified, large corals (including ESA-threatened-species) over two meters in diameter in SE FL identified with active disease. This includes restoring coral health by smothering diseased tissue, creating a “fire break” to arrest disease progression and covering the newly exposed skeleton with chlorinated epoxy. These activities are essential to save the largest, oldest, and most resilient corals in SE FL affected by disease. ”