Here is something that I don’t think a lot of people give much thought to: artificial reefs. Something artificial doesn’t sound that nice, does it? However, artificial reefs can be beautiful as well as fascinating and beneficial to a huge diversity of organisms. The other day, a friend sent me a news article which she thought I would be interested in, and I was. It concerns an abandoned oil platform in the Gulf of Mexico that has become a popular destination for recreational scuba divers. Now, a massive structure built for the sole purpose of extracting oil from the Earth is certainly not very environmentally friendly. However, when a metal structure such as an oil platform (or even something as simple as a dock) sits in the ocean for long enough, it becomes encrusted with all sorts of organisms. Sessile (non-mobile) organisms such as corals, sponges, barnacles, bryozoans (“moss animals”), and mussels, which all have free-swimming larval stages, will settle onto these structures and begin to grow. These types of organisms are usually filter-feeders, though some are photosynthetic (as is the case with most corals). So the encrusting organisms filter tiny food particles out of the water, or manufacture their own energy from the sun, and can soon cover the entire submerged structure. These organisms in turn attract many fishes and other free-swimming creatures. Tiny fishes may feed on and live amongst the sessile organisms, larger fishes prey upon the smaller ones, and so on. Seals, sea turtles, and even sharks and cetaceans may be attracted to the increased abundance of life around these structures. This is the normal progression of life that occurs in a natural coral reef (or rocky reef, or kelp forest). However, with an artificial structure, it often occurs where there are no other structures available for organisms to settle on or congregate around. So you can see how an artificial structure, even one that may have originally been environmentally unfriendly such as an oil platform, can give rise to a massive profusion of life. Increases in biodiversity and species richness are not only good for the environment, they’re good for people as well. As I mentioned earlier, many of these structures become very popular dive destinations because of all the amazing and vibrant sealife. This is often the case with shipwrecks as well, including my personal favorite, the Yongala. This shipwreck, sunk on a sandy seabed in the open ocean, has attracted so much sealife, and such LARGE sealife, that it is now one of Australia’s top dive destinations. People go to see it at least as much for the sea creatures as for the interesting maritime history.
Back to the oil platform in the article I mentioned earlier. That particular structure is known as High Island 389-A, and it is slated for destruction. Why, you ask? Apparently, the U.S. Interior Department has rules governing non-producing structures such as dormant oil platforms, which gives the owners of said platforms one to five years in which to remove them (this one was abandoned several months ago). And by remove, they mean with explosive blasts. Obviously, all the lush sealife that is living on and around the structure would be killed in the process. According to the article, it was estimated that anywhere from 800 to several thousand fishes would be killed, and that’s only the fishes. Of course all the sessile organisms would be destroyed. The larger marine life that frequents the structure, such as turtles, dolphins, and sharks, would either be killed or driven away. So why on Earth would these structures, which are supporting so much life, even need to be destroyed, you may ask? Because it’s the law. The Interior Department does actually have some legitimate concerns for doing so, such as the risk of potential oil leakage from the abandoned well. However, couldn’t there be some less invasive, less expensive way of minimizing that risk? I am no expert on oil platforms, but it seems to be that removing this (and the other 650 structures that may face a similar fate) would not only be incredibly destructive, but unnecessarily expensive. It seems to me that the benefits of preserving these structures far outweigh the risks, and it appears that I’m not alone in this belief. Many different groups are noted to be campaigning for the preservation of these abandoned oil platforms, including The Gulf of Mexico Fishery Management Council, the Coastal Conservation Association, and nonprofit organizations such as Save the Blue. I encourage everyone to go check out those last two links especially, as they contain a great deal of in-depth information about these “Rigs to Reefs” oil platforms, and what you can do to help protect them.Now, just because I think this topic is really interesting, I’d like to mention something slightly more academic and less of an activism issue. Artificial reefs are not always just formed incidentally, they are sometimes purposefully installed. I first became interested in the whole idea of intentional artificial reefs last year, when I visited Bali, Indonesia. I traveled to Permuteran on the northern coast of the island. There, when I was snorkeling in the incredibly clear waters just off the beach, I discovered a series of metal structures that had been built and sunk in those shallow waters for the express purpose of allowing corals and other sessile organisms to colonize them. However, these aren’t just simple metal structures dropped in the water and left there. They are actually hooked up to a low-voltage current generator. This is called Bio-Rock Technology, and what the electrical current does it stimulate the precipitation of limestone from seawater, which is naturally high in calcium and carbonate ions, which in turn form the minerals calcite and aragonite, which make up the sedimentary rock called limestone. This enhanced accretion of limestone onto the metal structures encourages corals to settle and grow much more rapidly than they normally would (small coral colonies are also transplanted by hand onto the structures, where they quickly anchor themselves). Of course, this then invites all sorts of fishes and other marine life to take up residence, allowing the growth of a reef to happen several times faster than it would in nature with no stimulation. This particular reef in Bali is known as the Permuteran Artificial Reef Project, and is one of the largest and most well-known of its kind. It is a fantastic method of coral reef restoration, as reefs that are damaged by natural processes such as cyclones, or by human activities, can take many decades to recover. I really wish this method were better-known and more widely used, as I think it has very important implications for coral reef conservation.
Anyway, my main point in writing about this subject is that I think all coral reefs, both natural and artificial, are deserving of better protection worldwide. Artificial reefs just seem to be far more overlooked than natural ones. I really hope that this brief post will provide a jumping-off point for people to learn more about artificial reef preservation. As always, I welcome any questions or comments on the subject, I’d be only too happy to elaborate on anything I may not have done justice to.