The Current State of Coral Reefs
Coral reefs are under a lot of pressure at the moment. Corals are under threat from climate change, bleaching, overfishing, pollution, plastic, crown of thorns starfish… you name it! Just so many of them!
Many reefs have been damaged by humans in the last 50 years. Ocean Gardener, an Indonesian coral reef foundation, has been working hard the last few years to spread coral education, and easy reef restoration techniques in Indonesia.
This foundation, created in 2016, has been planting over 50,000 corals since its creation. And 32,000 corals only in the last year.
Restoration Techniques
They use different techniques depending on the habitat, and the species needed in the particular restoration work. They spent the last few years trying to imagine an easy, cheap, organic technique to complete this mission. And they did a pretty good job with that! Depending on the project, if we have a rubble field to start with or a slightly damaged reef, obviously the job is going to be different.
The Foundation Work: Laying the Groundwork
When it comes to reef restoration work, there are a few processes that need to be respected.
The foundation work.
This is when you start out of nothing, just a rubble field. The first step is to try to revive the reef foundation. The coral species in that particular habitat would dominate the reef floor. It takes a few years to build that particular layer of corals. Usually, that layer is composed of branching or foliate hard coral species. In the shallows, they will be composed of thick, dense skeleton species, and in the more sheltered or deeper, they will be composed of skinnier, porous skeleton species. Maintenance during that phase, especially removing parasites, is very important.
The finishing touch.
The Finishing Touch: Ensuring Diversity
Once the foundation layer of species, that will provide shelter for all the others is set. We can start planting one by one, the less dominating, massive, slower-growing, more aggressive species. This slow, time and manpower consuming work are important to bring back the diversity, and all the building blocks that allow the reef to strengthen.
Drawing Inspiration from Seaweed Farming
Ocean Gardener, for this foundation work, extrapolated a technique by observing the seaweed farming techniques that Balinese people from Nusa Penida and Nusa Lembongan island have been using for the last 50 years. Just using wooden stakes and ropes, these peoples are able to produce tons of seaweed for the agar, ice cream, and cosmetic industry.
They just replaced the plastic rope with a more ecological cotton rope. Use the same wooden stakes that are collected up the hills from a fast-growing bush tree and that have the useful quality of not rotting in seawater. With added imagination and a bit of bamboo, they were able to use that technique not only to plant branching staghorn corals (Acropora sp), but also for thin, fragile, foliate hard coral species to plant hedgehog coral (Echinopora lamellosa), or cabbage coral (Montipora foliosa). All these very important corals constitute the reef foundation hard coral species.
Because these fast-growing corals have managed to dominate shallow reefs, just by overgrowing every other species. Their defense mechanism is quite rudimentary. And of course, with any successful species, nature has also developed a number of very efficient parasites. Unfortunately, the fish that feed on these predators were removed by overfishing. It led to the infestation of crown of thorn starfish and other drupella coral-eating snails. So these corals were the first ones to go, and after it’s just a domino effect, and the rest of the reef goes. That’s why these species are the most critical to restoring first.
Coral Restoration: An Organic Technique
This 100% organic technique is now used to plant table acropora, massive species of hard corals like Galaxea or Lobophyllia, and even some soft corals. The location they choose is in front of Ped village. The reef has been damaged by pontoon moorings, the incessant boatload of snorkelers, and reef walkers. And over the years, a large field of coral rubble has now replaced the former pristine reef.
Community Involvement in Coral Restoration
A community group of over 20 coral lovers was created and started working together with Ocean Gardener. After some quick training, these enthusiastic local conservationists that have seen their reef going down, over the years, were very motivated to do the right thing and fix it.
Setting up a Coral Nursery
They started by creating a coral nursery in the shallow lagoon behind the small fringing reef. In that part of the reef, the water is slightly warmer. Slowly adapting corals to a higher temperature. Nusa Penida is famous for its cold upwelling currants which are synonyms of Mola’s sightings. Unfortunately, some years we don’t even wear a wetsuit anymore. So accelerating temperature adaptation is of the uttermost importance. The nursery was set up with a high diversity of fast-growing, shallow-water corals, and new varieties are regularly added to the species mix. it can supply thousands of coral pieces every month now. Without it, no massive work is possible.
A location on the shore was provided by the local village. Coral fragments are harvested from the nursery and brought to shore where the community participates in mounting the corals on the cotton ropes. Then the group separates into three teams. During a first dive, the team of four divers sets up all the stakes, in the correct place, at the correct distance. Then a transport team brings all the mounted ropes from shore to the restoration site. There, a snorkelling team does the junction, supplies all equipment to the divers, and assists them the best they can. A well-greased synergy that allows the whole team to use the small current free windows in the most effective way.
Coral Restoration: The Final Steps
The finishing work, is the hardest, as all corals need to be directly planted one by one on the reef. Which is a laborintensive, slow process. A very technical work, that requires a lot of coral ecology knowledge.
Author and photographer Vincent Chalias
This article was originally published in Scuba Diver ANZ #55
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