By: Marina Garmendia
Alongside the Coral Reef Restoration Assessment and Monitoring (CRRAM) Lab, Marina Garmendia presented a poster at the 50th annual Benthic Ecology Meeting (BEM) in Portsmouth, NH 2022. The research poster was based on micro-fragmentation research done in Southeast Florida.
Figure 1. Stony coral microfragmentation poster presented at the BEM conference in Portsmouth, NH 2022. By: Marina Garmendia and members of the CRRAM lab.
To learn about the micro-fragmentation methodology, I invite you to visit our last blog post, where this technique is outlined step by step.
The principle objective of this research was to compare survival and predation prevalence between four coral species at two sites; in-situ nursery versus a natural reef site. The coral species compared were as follows, Montastraea cavernosa, Pseudodiploria clivosa, Solenastrea bournoni, and Siderastrea siderea.
One of the main challenges of micro-fragmentation is the impact of fish predation at the natural reef site. The tiny coral pieces become a perfect snack for fish predators like parrotfish and butterfly fish; they can devour them with one bite. Anti-predation methods have become a hot topic among coral restoration scientists. The goal is to investigate how to overcome fish predation and achieve long-term micro-fragments survival.
Figure 2. Tasty looking microfragments of Montastraea cavernosa in the in-situ (underwater) nursery. By: Shane Wever, CRRAM lab
Multiple research projects focus on the mitigation of fish predation. Currently Miami University, Nova Southern University (NSU), and other partners that are part of the Southeast Florida Coral Reef Restoration Hubb have designed new bases that provide protection for the microfragments once they are placed in the natural reef site. Protection measurements involve physical barriers to avoid fish access as well as adding zoanthids or sponges that could provide chemical camouflage for the out-planted corals.
What's your favorite method?
Figure 3. a) Cement cones, b) Acropora cervicornis, and c) a spike structure are used as physcial barriers to prevent fish access. As well as d) attached zoanthids used for chemical camouflage.
Based on the research preformed in the CRRAM Lab, we have noticed that predation happens in the first couple of months post-out-plant. For this experiment, the ocean nursery fragments were placed on coral tables (Figure 3 and 4) while in the natural reef site, the fragments were placed on cement bases (Figure 5). Monitoring was conducted for 1 week and monthly for two months; to compare, observe and monitor the fate of these microfragments. Our prediction and hope were that the micro-fragments placed in the sandy area (in-situ nursery) are protected from all predatation acitvities and thus they will have experince less instances of predation and increase their survial chances. After the study, the in-situ nursery fragments experienced 0% predation (as predicted), while the fragments placed on the natural reef had up to 26% instances of predation.
Figure 3. Marina Garmendia in the in-situ coral table nursery. By: Shane Wever, CRRAM lab
The proyect idea was to leave some micro-fragments in the in-situ ocean nursery protected from predators for the first months and then transfer them to the natural reef site. Survival of almost all species was above 90% with the exception of Solenastrea bournoni. Surprisingly, all fragments died in the in-situ nursery during the first three weeks of the study due to unknown causes, while 80% of these fragments survive in the natural reef site.
Figure 4. Comparison between initial outplant of the microfragments in the in-situ nursery, and the 2-month monitoring period. By: Marina Garmendia
Figure 5. Some fishes are checking out and potentially predating the natural reef site bases. In this photo, there are five Pseudodiploria clivosa microfragments. By: Marina Garmendia.
So.. what is going on?
What does this mean?
This study concluded that micro-fragmentation survival in out-plant sites is specie specific. Ongoing studies will continue monitoring the fate of coral fragments, by increasing the numbers of fragments and species at out-plant sites and comparing their survival. Eventually, a better understanding of anti-predation methods will come from this monitoring and will increase the survival rate of micro-fragments; ultimately, increasing stony coral restoration efficiency.