Just How Effective Are Electrified Artificial Reefs?
Electrified Artificial Reefs are a technology which has the potential to contribute greatly to the protection and managemnet of coral reefs around the globe. Unfortunately, the technology has been kept out of the hands of most reef restorationists for nearly a decade. The costs and technical expertise needed to implement an electrified artificial reef are high, but the main reason this technique has thus far remained out of the hands of most coral conservationists is due to the patents and trademarked proprietary knowledge of BioRockTM that were filed back in 1996. Through the Save Koh Tao Group enough money was raised to begin one of our island’s largest underwater community projects to date, and the funds necessary to pay the hefty licensing fees to BioRockTM allowed us to bring this coral saving technology to our waters. The site was named Hin Fai (Fire Rock) and it still sits in-between Koh Nang Yuan and Koh Tao, where it has become a home to a wide host of different species that use the artificial structures as a habitat.
After only two years, the underwater transformer for Hin Fai broke down, and the funds that were needed to bring BioRockTM representatives back to the island to repair it were simply too high.
It remained off for another 6 years until their patents expired, at long last allowing us and coralAID to fix what had been damaged. The company has said that this technique allows corals to grow 3-5 times faster than under natural conditions, but in all the years that Hin Fai had been developing, scientific studies on the process of mineral accretion fell under the patent’s heavy restrictions, limiting our ability to prove or disprove the claims made by the company. These patents effectively muzzled scientific study that might’ve suggested that the assertions made by BioRockTM weren’t all that the company claimed them to be, so naturally we rejoiced when these limitations were finally lifted.
What We’ve Accomplished Since
After years of waiting and thanks to the help of coralAID, we’ve created an electrified artificial reef in Aow Leuk that we can call our own. The site has developed and expanded in a big way since the first parts of the Artificial Atoll were first deployed in August 2016. The creation of the Artificial Atoll was dreamt up and orchestrated by Chad and Bob, and with the help of dozens of our students and the CIS Australia team that were with us, his vision began to take shape. There was a staggering number of welds done on this structure, so many in fact that it actually caused me temporary blindness even with an auto-darkening welding helmet. The end result was well worth it though, as the atoll has exploded with life thanks to many coral fragments that were rescued from the sands in the surrounding area.
The site has then since seen the deployment of several structures and sculptures. The Transformative Trash Seahorse that won the Save Koh Tao Festival’s 2016 Trash Sculpture Competition went from an upcycled plastic lamp to a majestic artificial reef sculpture, with help from Conservation Diver Instructor George Bevan. The Seahorse sits in the middle of the atoll and has been adorned with many thriving coral colonies, along with an Acropora coronet to help it blend in with the structures that surround it, like it’s real-life equivalent.
Pau’s Electric Wave designs were the next structures to go down at the site, a total of four planted carefully around the atoll. The interns of 2017 played a big part in bringing these waves to the site and now each of their grids is packed with life.
At the end of last year on September the 14th, The Viperfish was deployed and an electric lure was rigged up by Robert Svenster (a.k.a. le Bob) to bring life and light to the sculpture. The concept that inspired this piece was drawn up on a small piece of paper in pencil and water colour earlier that year and can be seen pictured below.
Bob designed his own waves, built in such a way that they can be bound together to form expansive modular reefs. These latest additions to the area were designed with simplicity and replicability in mind so that our student and interns could help contribute to the artificial reef structure at the site under much more realistic time frames. With his new designs and more iron sculptures on their way, the site is on track to become one of the most beautiful artificial reef sites on the island.
Our Many Plans of Action
After years of waiting and thanks to the help of coralAID, we’re now able to test the effectiveness of this reef restoration technique for ourselves at our latest and greatest electrified artificial reef in Aow Leuk. The site is the culmination of years of hard work. While we were making the thousands of welds necessary to bind the structures together, Robert Svenster (a.k.a. le Bob) was busy refining and perfecting his open source mineral accretion designs that would electrify our rebar structures halfway across the globe at his workshop in Holland. Since the site was first deployed, we’ve been measuring the growth rates of 30 unique coral genomes across the Artificial Atoll and comparing those against their counterparts on our control dome that was placed at the same depth approximately 50 meters away.
Our curiosity hasn’t ended there. Both Chad and Bob’s thirst for more knowledge has sparked a new project, perhaps one of the most exciting in our program’s history. Bob meticulously designed and welded together 7 iron pyramids of identical dimensions, 6 of which will be cathodes each with their own amperage and the last remaining pyramid will serve as a control without any power running to it.
The 6 powered pyramids each have their own underwater transformers (coralAID NetV3 anodes) that are made of a Platinum-Titanium alloy meshing with a mixed metal oxide coating. This will allow the amperages to each of the pyramids to be controlled, and range from ¼, ½, 1, 2, 4 and lastly 8 Amps.
The pyramids have 320 fragments of equal sizes, 70 for each of the 4 genera we’ll be monitoring. Each fragment was placed across their grids in the same way, using cable ties that were retightened several times to ensure that each were firmly secured, and even the orientation of all the fragments was taken into consideration to minimize any potentially anomalous variables as greatly as possible. The genera chosen for the study include Acropora and Pocillopora, two species well known for their structural complexity and fast growth rates, alongside Porites and Cyphastrea, two slower growing submassive species that form similarly shaped aragonite skeletons making for good comparisons of one another. Other variables that will be measured include the environmental conditions of the site itself through HOBOware Temperature and Luminosity Data Loggers, pH, salinity and at the end of every year the skeletal density of the 4 coral Genera on each of the pyramids.
Now that everything is in place and the initial measurements with calipers have been taken, along with top down photos that are analysed using computer software, all that’s left to do is flip the switch and watch the pyramids bubble. We’ll return periodically over the coming years and continue monitoring the progress of the fragments here, accumulating a vast database of information so we can come to a strong conclusion about the success we’re having. With this data we plan on publishing a definitive study on mineral accretion technologies that can go on to inform Bob’s work in the future, our own restoration approaches, and provide coral reef managers across the globe with information on how these bioengineered habitats can improve their own efforts…or not.
In time, the science will reveal all. This unbiased study will show us just how effective mineral accretion can be for coral growth and survival rates, but one of the greatest benefits of this technique has already made itself evident to us. By electrifying our iron reefs, their structural integrity is dramatically improved, making our imaginations the limit when it comes to creative shapes and forms, while their chemical volatility with the surrounding ocean is drastically reduced as well thanks to the thick Calcium Carbonate crust that will lock up the rebar.
We will continue expanding our site in Aow Leuk, adding more artificial structures and sculpture to save what coral fragments we can from the mounting rates of sedimentation in the bay. While the work we’re doing in the area isn’t a silver bullet solution to the ever-mounting stresses these reefs are suffering from, it will certainly help slow the rate at which this reef is degrading. In only two years the site has flourished into one of our favourite artificial reefs on the island and in the mean time, we’ll savour the success that we’ve had here.