Two hundred more corals planted in Medalla Light project

After two recent outplanting expeditions in 2022, we have now planted 200 more Elkhorn coral fragments in our experimental restoration project sponsored by Medalla Light. Using recycled glass sand as part of our cement mixture, we are looking for a viable way to upcycle a waste product into a useful material for coral reef restoration. To get up to speed on this story, check out the beginning of the project.


Reef bottom with new coral fragments planted and marked for monitoring

An update on the progress

We had 300 corals planted by the end of 2021, only to later discover that the hotter-than-usual seawater temperatures during our September outplanting expeditions (when we planted the remaining 200 fragments from the initial goal of 300) resulted in a majority of bleached coral fragments. This happens, unfortunately, as sometimes the environment has other plans that we cannot control. But this did not discourage us from continuing the effort. In fact, the first 100 we planted back in June 2021 are doing well! Check out this video and notice the vertical growth on some of the fragments!



We decided to essentially restart the experiment by planting another 300 corals, but also continuing to monitor the 300 we planted in 2021. Thus, in February, we planted another 200 Elkhorn coral fragments and we will be back to the site in March to plant the last 100. So, after the final expedition, we will have 400 corals planted as part of the experiment.


Can you spot all the outplanted corals in this photo? Count them here, and then use the arrow on the right of the image to see if you're correct.


What's next?

After the outplanting is complete, we will be revisiting each of the experimental plots on a trimonthly basis. We will measure the growth and health of each fragment so that we can estimate success rate of the outplanting (% alive) and growth rate (how fast are they growing per cement mixture). Once we have generated the data, we will be able to confidently say whether or not using the recycled glass sand aids in coral growth (if the rate is determined to be faster than the control cement mixture) or if there is no difference (the growth rate is the same, which is still an excellent result). Ultimately, we want to show that the use of this waste product does not hinder coral growth so that we can continue to incorporate it into this conservation initiative.


The net found on the reef. Photo by Raul Ortiz

*During the September 2021 coral outplanting, the team found a huge derelict net on the reef that had broken several Elkhorn branches. They were able to use some of these fragments for the outplanting, but unfortunately they were part of the group that was impacted by the warm water.


**We get a lot of questions about how you can donate bottles to our effort. We wish we could accept them! We actually do not need a enormous number of bottles for our purpose, since what we are doing is still a small-scale pilot project. However, we are working hard behind the scenes to find solutions! We are meeting with community leaders, citizens and other scientists to come up with a plan for recycling bottles on a larger scale. Stay tuned!