Conservation - Reef Restoration Project with Oceanus AC
Written by Rob Mukai on Sep. 20, 2018
We all know that our coral reefs around the globe are critical to our marine ecosystems. 25% of the biodiversity of the ocean lives in the coral reefs that only cover 1% of the ocean floor. They are in relatively shallow water and are the canary in the coal mine for ocean warming and acidification. Every one has heard that after the mass bleaching event in 2016, 50% of the Great Barrier Reef in Australia is dead or dying. Here in Xcalak we are blessed with the second largest barrier reef in the world, the Great Mayan Reef. It is not in as bad a shape as the great barrier reef, however, it doesn't mean that we have come off scott free. A survey of the reef in 2008 found 50% of the corals in the Great Mayan Reef were considered healthy. By 2012 that number was down to 9%. In order to save our reef, something must be done.
Oceanus AC is a conservation NGO that has been working to restore coral reefs in the Mexican Caribbean and the Gulf of Mexico since 2007. They initially started in Vera Cruz on the Gulf of Mexico in 2010, but their second and third sites were in Puerto Morelos and Xcalak in Quintana Roo, on the Great Mayan Reef. Since then, they have transplanted over 30,000 colonies all around the Mexican Caribbean and the Gulf of Mexico. They have been innovators in creating methods to harvest broken pieces of coral, put them in nurseries to regrow, then replanting them in areas that need new coral growth. In 2016 I had gone out with them to plant some coral that they had been regrowing in their first site in Xcalak. At the time, I had asked if we could do a similar thing in the north end of the beach as well. Fast forward a couple of years and we have started to do reef restoration up north here.
Elkhorn coral (Acropora Palmata) is an important coral species because it creates structure for reefs, and provides shelter for fish and other species to grow. They are usually found in the reef crest, so wave action from storms can break off pieces of the coral. These broken fragments can sometimes find purchase in the sand in relatively calm areas or get wedged into other reef structure and can start growing again. Unfortunately a lot of them just end up dying and becoming sand over time. What Oceanus AC does is find the broken or otherwise un-anchored elkhorn coral on the sea floor, put them on PVC connectors, then put them in nurseries where their survival rate is 60-90%. Once the coral fragments have sufficiently grown, they are then transplanted back into the reef. They have a couple of sites south of town where they have been doing this for a few years now. This year a group of home owners and Inn owners came together to get trained to do this work north of town.
The Training - Day 1
First day we had a 2 hour class on the biology of coral and theory behind work. The ways that coral reproduces both sexually which is important for genetic diversity and asexually, the reproduction method we take advantage of to restore the fragments. We learned about how coral can be damaged by bleaching, disease, and predation. We also did a dry land run of what it was we were going to do the next day.
The Training - Day 2
So this was an in the water day. We first went to a spot we had identified earlier a little north of the Inn, near a cut in the reef. They had already anchored a nursery to the bottom. The first order of business was to find fragments. We all spread out in the area as there were a lot of Elk Horn coral patches around. In no time we had enough to fill the 70 spots for the nursery.
Once the fragments were brought on board the boat, we started connecting them to the PVC connectors using zip ties. It sometimes required breaking them down or shaving off some substrate in order to get them to fit into the connector.
Next we had to screw them into the nursery. The nursery is about 10 feet down, so its hard to do more than one per dive. But we had enough people that it went in pretty quickly.
Finally, we had to measure the corals, and report on their condition. Including height and width, any bleaching or disease. This was surprisingly difficult as it was really hard for some of us old folks to see the numbers on the rulers :)
First thing is in 2 weeks we will go back out to the nursery to clean it of any algae and check on the progress of the corals. Then next month in October we will have another session, which we will make the bases for the corals and affix them to the areas that we will be transplanting corals. We will probably also put in more nurseries as well. We have found another couple of sites that are good candidates.
So for the next three months we will be cleaning the nursery every two weeks, doing measurements and checking progress of the corals every month, and finally,. if all goes well, transplanting our first batch in 3 months or right around December.
Once we get into the rhythm of things, we should be able to do 4 transplantings a year. Come check it out!