By: Adriana Bañuelos, Isabel Rios Amador, and Marina Garmendia
Figure 1. Marina Garmendia (Coralisma co-founder & CEO) preparing coral bases for restoration. Picture taken by Fran Reina.
Introduction
Stony coral tissue loss disease (SCTLD) is fast-spreading and has increased mortality rates of stony corals in the Caribbean over the past decade. The Arrecife de Puerto Morelos National Park (APMNP) found in Mexico’s Mesoamerican Reef has been a marine protected area since 1998 , containing approximately 90 km² of coral reef (Ardisson et al., 2011; Caballero-Aragón et al., 2020). Due to rising ocean temperatures and SCTLD outbreaks, there have been notable reductions in stony coral cover within the Park, highlighting the need for active restoration efforts (Garmendia et al., 2023).
In this blog, we will dive into the exploration of using microfragmentation as a technique for coral recovery in SCTLD susceptible species at APMNP.
Figure 2. Marina Garmendia (Coralisma co-founder & CEO) and Dave Gilliam (Associate Professor at NSU, CCRAM Lab) coral monitoring after outplants. Picture taken by Fran Reina. Objective
The substantial damage caused by a SCTLD outbreak in 2019 called attention to the critical need of restoration efforts in the region. The aim of this study was to introduce tissue of SCTLD susceptible species and examine the disease prevalence over time. Through repeated monitoring, we were able to inform the park management about the optimal timing for initiating active restoration efforts.
Figure 3. Coral bases before being placed for restoration. Picture taken by Fran Reina.Methodology: What is Microfragmentation?
Figure 4. Schematic of microfragmentation process. A) Rescued corals from Dry Tortugas National Park (Carly Dennison UM) B) Diamond blade band saw fragmenting stony corals (CCRAM Lab). C) Microfragments from the CCRAM Lab in-situ nursery. D) Montastraea cavernosa on the last stage of the microfragmentation process (CCRAM Lab).Microfragmentation is the process that involves collecting naturally unattached coral fragments (Corals of opportunity), quarantining them in an ex-situ (tank) nursery to ensure they are disease-free, and then cutting whole coral colonies into < 4 cm microfragments to optimize growth and genetic diversity. These fragments are then glued onto small cement pieces to heal and grow in an in-situ nursery before being placed at restoration sites to mature and eventually reproduce, enhancing coral and reef diversity.
Want to know more about the process? Check out our blog: International Collaboration for Stony Coral MicrofragmentationStep 1: Restoration Methods
In November 2022, 1,504 microfragments of Montastraea cavernosa, Orbicella annularis, and O. faveolata were planted at six reef sites using 303 cement bases with densities of 3 and 7 cement plugs per base.
Figure 5. APMNP with the outplant and control sites map and table showing location, depth and class, reef zone and coral cover before restoration. (Inset: APMNP in Mexico highlighted with red box)(Garmendia et al., 2023).The bases were randomly placed within a 10-meter radius of a central pin, labeled with species, density, and genotype information, and their positions recorded for future monitoring.
Figure 6. Cement bases with 3 and 7 stony coral microfragments. (55: M. Cavernosa; 230: O. annularis; 128: O. faveolata). Produced by Reef Aquaculture Conservancy A.C.
Figure 7. Schematic and visual representation of outplant experimental design (Garmendia et al., 2023). Step 2: Tracking
After outplanting, monitoring surveys assessed the survival and health of microfragments, checking for bleaching, disease, and predation, and documenting their status as alive, dead, or missing. Microfragment growth was measured by photographing each base and tracing the outlines of the microfragments during initial and final monitoring periods using Image J.
Figure 8. Percent M. cavernosa, O. annularis, O. faveolata microfragments showing predation, disease and bleaching over a period of 9 months (Garmendia et al., 2023).
Figure 9. Coral base #185 with O. annularis microfragments before (left) and after restoration (right). Picture taken by Fran Reina, analyzed under Image J (Garmendia et al., 2023).Step 3: Statistical Analysis
Using the data from our tracking methodology, live tissue area, relative net growth (relative change in live tissue area), mean relative change and absolute growth rate were calculated.
Table 1. Table showing absolute, mean, and relative microfragment growth results (Garmendia et al., 2023).For more information about our methodology check out our Blog: Restoration of Stony Coral Tissue Loss Disease susceptible species with microfragmentation in Mexico.Results: Microfragment Survival and Growth
Our study marks the first long term project using microfragmentation as a coral restoration tool in the Mexican Caribbean. By examining the outcomes at various outplant sites, we established a baseline for this approach. Specifically, we analyzed spatial and interspecific variations in survival, net growth, and microfragment health.
Disease
Results showed no significant differences in disease prevalence on natural colonies between outplant and control sites.
Figure 10. Disease prevalence at six sites: yellows (shallow sites), reds (intermediate sites) and blues (deep sites) over a nine month period (Garmendia et al., 2023).Growth
All species of coral had varied in absolute, mean, and relative growth. Also, relative net growth was significantly affected by location.
Figure 11. Graph showing the relative net growth (cm) at each location by stony coral species (Garmendia et al., 2023).Survival
Overall microfragment survival, considering species and locations, was high (84.28% ± 3.28). Intermediate depth sites (red), La Pared, and La Bocana, exhibited significantly greater survival (yellow) than Radio Pirata. Deep sites (blue), Cazones and Tanchancte, showed lower survival than Jardines and intermediate sites.
Figure 12. Graph showing stony coral microfragment survival by location in a period of 9 months (Garmendia et al., 2023).Discussion: Environmental Stressors & Future Suggestions
Overall, the introduction of SCTLD-susceptible stony coral species microfragments did not lead to an increase in disease among the surrounding natural colonies, indicating that initiating restoration activities in the APMNP is feasible. Although there was high survival, low levels of disease and predation, there was great variability between species relative to their location.
Restoration site: Survival -- After nine months, high survival was observed across all species overtime, and survival was higher at intermediate depth sites.
Figure 13. Coral base #185 before restoration (left) and after restoration (right) showing survival after bleaching on all fragments except one. Pictures by Fran ReinaRestoration site: Growth
Location significantly influenced relative net growth
Figure 14. Coral base #268 showing positive growth results after the bleaching event (August 2023). Picture by Fran ReinaMacroalgae and Sedimentation
Net microfragment base growth was not significantly impacted by macroalgae and sedimentation, but location had a significant effect on these factors. Sedimentation was notably higher at shallow reef crest sites compared to intermediate and deep sites, while macroalgae levels did not vary significantly by depth.
Figure 15. Coral bases impacted by microalgae and sedimentation before cleaning (Garmendia et al., 2023).Temperature – Bleaching
Optimal coral growth temperature is 23°C to 29°C, with bleaching starting at 29°C to 30°C (NOAA, 2024). In August 2023, peak temperatures of 33.05°C caused severe bleaching in many natural colonies and an average bleaching rate of 83.83% among outplanted microfragments, with variation by location linked to water depth and temperature. However, there was no significant difference in temperature between locations or depths.
Figure 16: Average daily logger temperature (HOBO Pro V2). The dash lines represent the five monitoring periods, and the different colors represent each location (Garmendia et al., 2023).
Figure 17. Severe bleaching among natural corals in August of 2023. Pictures taken by Fran Reina.Predation and Disease
Low predation pressures were observed in the first two months in comparison to a study conducted by Page et al. (2018) in Florida and Hawaii where predation was a major bottleneck of microfragment mortality. Disease prevalence remained low across all locations. Although there was higher SCTLD prevalence in natural colonies at outplant sites compared to control sites, there was no significant increase in disease over time.
These findings suggest that restoration is feasible despite the presence of SCTLD.
Figure 18. Rainbow Parrotfish near coral base. Picture taken by Fran ReinaConclusion: Did the restoration of stony coral tissue decrease the prevalence of SCTLD in natural coral colonies the APMNP?
Yes, but there is still a lot to do...
Figure 19. Thriving Coral Base after restoration. Picture taken by Fran ReinaOur study found that introducing SCTLD-susceptible stony coral species as microfragments does not increase disease incidence in surrounding natural colonies, suggesting that restoration with these species is feasible within the APMNP.
Figure 20. Thriving natural coral reef at APMNP. Picture taken by Fran ReinaAdditionally, research by Forsman et al. (2015) showed substantial growth and fusion rates in small coral fragments on ceramic tiles, and Page et al. (2018) observed that microfragment arrangements of Orbicella faveolata produced more tissue than larger fragments.
Figure 21. Coral base with O. annularis fragments after restoration. Picture by Fer ReinaThis is the first major microfragment outplant with a long-term monitoring in the Mexican Caribbean.
Nonetheless, environmental conditions and chronic pressures are impeding the growth and survival of microfragments, potentially limiting the long-term success of restoration in the APMNP. We recommend that additional microfragmentation efforts be performed within this region, taking into account site limitations and other factors, to better evaluate the techniques success in the Park.
Figure 22. Coral base #100 with O. faveolata microfragments placed for restoration. Picture by Fran ReinaIn Summary...
Our study showed that while microfragmentation offers promise for coral restoration, various environmental pressures must be managed to maximize success. Future research should explore the impact of fragment size, species-specific performance, and acclimation to site conditions. By addressing these factors, we as a community can enhance the feasibility and effectiveness of large-scale coral restoration initiatives.
Figure 23. Marina Garmendia (Coralisma Co-founder and CEO) and Dave Gilliam (Associate Professor at NSU, CCRAM Lab) holding a coral base ready to be placed for restoration. Picture by Fran ReinaLearn More: (Citations)
Restoration of Stony Coral Tissue Loss Disease susceptible species with microfragmentation in Mexico
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