Two years ago, View Into The Blue, Teens4Oceans, and Harbour Village Bonaire began a project allowing eyes around the world to view the underwater world surrounding Bonaire’s premiere resort, Harbour Village. As the project moved forward on-site dive manager, Chris Ball, along with Bonaire’s own Junior Ranger Program, cultivated a Teens4Oceans chapter. The Junior Rangers partnered with The T4O group from Gulliver Schools in Miami to drive the project forward. Bringing all of these groups together we designed an experimental project focused on learning more about the local coral reefs on Bonaire. It took nearly 2 years to receive permits and permissions from the local governing bodies but in February of 2017 we were able to deploy phase one of the initiative.
Coral restoration has been at the forefront of marine sciences for years now. A particular restoration technique has largely flown under the radar over the past few decades and for good reason. “Electrifying” reefs has been done around the world but has never been properly studied and there is very little data to support the method. Originally developed by Professor Wolf Hilbertz and Dr Tom Goreau as BioRock Technology, the method has been used at numerous sites all over the world. Our hope is that using the underwater cameras, a suite of voltage and water quality sensors, and students and scientists alike, we can produce a long term set of useful data that can further the impact of this decades old technology. With reef protection becoming a more and more pressing topic every day The T4O Chapters, View Into The Blue and Harbor Village have developed a plan to test this concept in a cohesive and scientifically sound way in hope of bettering our understanding in how to protect our extremely important marine ecosystems.
Here’s how the electric reef, (BioRock), method works. Corals, like many marine invertebrates, build their skeletons out of calcium carbonate. This energy intensive process is done by pulling calcium and carbonate ions from the ocean and secreting them as a skeleton. In a similar fashion, an electrolysis reaction accomplishes the same feat. Electrolysis is basically the idea that direct electrical current can facilitate a chemical reaction that wouldn’t otherwise happen. We decided to see if using this concept would also facilitate coral growth. What we did is actually quite simple. Our team of young T4O students built two metal domes out of re-bar, a control and a powered, and sank them in the ocean. Here’s where things get pretty cool. Once underwater we attach a negative wire to the metal dome, this makes the dome a cathode. Then we place the anode, or positive, inside the metal dome and we power it up. Instantly we begin to see tiny little bubbles appear in the structure and days later the rebar become coated in a nice layer of calcium carbonate making it appear white. the comparison to the control is a stark difference in rusted metal to clean while limestone.
On both the 360 and Static ocean cameras you will be able to follow the project and observe the stark contrast between the two experimental domes. The electric dome has already turned white and it is only a matter of time before life begins to settle in on the new habitat. The other extremely exciting consequence of this project will be the increased habitat for fish. the structures actually act as fish aggregation devices, or FADs. We are curious to see whether fish will inhabit one structure over the other so that we can find out why. The questions we can ask and research are truly unlimited and it’s a fantastic opportunity to have eyes i the project for our community to follow along.
We cannot immediately place corals on the structure, but in the next couple weeks we will begin that process. Our hope is that corals on the electrified reef will grow much faster than those on the control. But, simple visual observation is not enough to prove the method works. We have also installed a suite of data probes and electrical measurement equipment. We have the ability to measure the current both on the powering system and directly on the structure, currently about 3.2 amps are powering the electrified reef. We also have installed probes that will be recording pH, Temperature, Salinity, Dissolved Oxygen and Oxidative Redox Potential. For our students and the scientists working on this novel project these reading will be the difference for finding out the truth about electrified reefs. We hope that this project will be the foundation for resorts like Harbour Village and others like them to be able to build and care for the coral reefs on a reasonable scale right out their front door.