Evolution of Artifical Reefs: Chalok
By Chad Scott
Whether for attracting fish, growing coral, restoring reefs, or just art and sculptures; the value of artificial reefs is becoming more apparent to many reef mangers around the globe. For almost 6 years now we have been building, deploying, and maintaining artificial reefs in Chalok Ban Kao, Koh Tao, in a reef which was previously destroyed by anchors and coral bleaching. They haven’t all been successful, but for the most part they have all fulfilled their intended purpose, and can be considered a success. But don’t just believe us, check out the pictures below to see for yourself how these artificial structure can evolve in to diverse and productive ecosystems.
#1. THE ORIGINAL BOTTLE UNITS
The bottle units were the first installation of what has become one of our favorite coral reef restoration methods. The bottle nursery units are easy to make, easy to deploy, and work great. By 2015 we have installed over 400 units around the island to secure, broken corals, restore damaged areas suich as boat groundings, and create 'diving trails' to facilitate underwater navigation to and around alternative dive sites. These units have worked so well, that many others have also started using them, both in Thailand and abroad.
#2. THE FLOWER DOME
The flower dome is a simple and small structure that was put down in an area destroyed by anchors and filled with corals that had been growing on our nurseries nearby, and within only a few short months it had developed into a beautiful small reef with loads of fish around it.
#3. THE SEA STAR
The SeaStar was built by a few of our interns and put down in the water in early 2012, in an area with major anchor damage. The structure has grown very well, and also survived the 2014 bleaching event, with almost complete coral recovery.
#4. MIEKE’S WHALE
This whale structure was designed and built by one of our interns, Mieke, as one of her last little projects to leave something behind for the island. The structure has been doing great, and at night we usually find two large Scribbled Filefish sleeping in it.
#5. THE MINI PYRAMID
The Mini Pyramid was made real quick using some scrap metal from building a larger pyramid (see #6 below), and it has grown beautifully. Today it is so covered in corals that I doubt any outside visitors would ever know it is an artificial reef.
#6. THE PYRAMID
The pyramid is also put in an area damaged previously by anchor before we installed many mooring lines in Chalok. In June 2014 it was hit by an anchor or fishing net and flipped over, but with some quick repair work it was looking great again just a few months later.
#7. THE HELIX
The Helix was just an idea we wanted to try for a while, and became a little art project for the low season. It was put down in the middle of the monsoon season, but survived well and a few years later is teaming with life. One of the best parts about it is watching the purple table coral (right side of the picture) work its way up the rungs off the helix like climbing a ladder.
#8. SPIRAL DOME
We have put down over 50 spiral domes such as this around the island, the design is quick and simple to build, and uses just 1.5 lengths of steel. It is an effective design, however a lot of the structural integrity relies upon the welds, so it is crucial they are done well. Like other structures in the area, the unit experienced a high degree of bleaching due to warmer sea waters in 2014, but has since recovered beautifully.
#9. Natty's Nurseries
