Palm and The World Rocky Breakwater Artificial Reefs
Artificial reefs or rocky breakwaters constructed of natural materials, such as the Palm and World, are excellent for enhancing marine ecosystems. On a much smaller scale than the mega-projects of Dubai, artificial reefs and breakwaters have been deployed in virtually all inhabited continents and around oceanic islands of the world. The increased interest in artificial habitats comes from a diversity of interested parties from developers to conservationists. While their initial goals may be different the end result is an increase of benthic habitat that means significantly enhanced food, shelter and marine populations.
Professor Joe Valencic, left, with fellow scientist Dr Wolf Hilbritz examine rocky breakwaters of Dubai, UAE
As a marine scientist, I have been involved with the establishment and monitoring of underwater ecosystems for several decades. Some of the early pioneering work on artificial reefs was done off the coast of southern California. Many mistakes were made in terms of reef placement and the type of material used. Even today, twenty years after their placement off Newport Beach California, automobile tire reefs incorrectly placed and scattered by storms are being disassembled. Aircraft, boat and car reefs are breaking down after years of submersion in seawater.
One success story has been a natural rocky reef complex located off San Clemente California, Named PAR, Pendleton Artificial Reef, it was built as a mitigating effort to help counteract the ecological damage due to the thermal effluent of the San Onofre Nuclear Power Plant. Natural rock materials quarried from Catalina Island were used to form the numerous reef modules located in approximately 40 feet of water on a previously barren sandy ocean bottom. I worked with the California Fish and Game to monitor the ecological development of these reefs as they turned into one of the best sport fishing areas of southern California.
The Palm Islands and The World projects have caused a stir among environmentalists. One female marine biologist recently went so far to say to the press that the islands are destroying sea life. "I've dived down there and because of the dredging and sedimentation, visibility is not good. There is an ecological imbalance. There are few fish because the natural habitat has been destroyed. Artificial reefs and cement barges in the sea are not attracting that many fish. They are migrating to other places because there is nothing for them here. There is something disturbing the ecological chain," she said.
When statements like this reach the press, the accompanying headlines generally tout ecological disaster of the highest magnitude. After all, sensationalism does sell newspapers. However, if the press were a bit more informed and did a bit of due diligence in their reporting the story would make quite a bit more sense to everyone, environmentalist and developer alike.
First, dredging and the creation of the man-made islands off Dubai will inherently cause increased sedimentation and reduce underwater visibility just like their creation will affect the long shore current and distribution of sand along the beaches of Dubai. Nakheel has taken great efforts to mitigate the detrimental effects of sand flow along the coast and has a solid engineering solution to the problem at great-continued expense. In my opinion, Mother Nature will mitigate the effects of the poor water clarity or high turbidity after the dredging has been completed. It is correct that there will be short term impact of the added sediment cover on rocky areas however the pre-construction marine environment around Palm Jumeirah and The World was one of a thin veneer of sand over a consolidated sedimentary rock base. In terms of biomass, this is considered to be one of the least productive marine environments so adding sediment to sand cannot be considered a true ecological disaster. In fact, after making hundreds of dives in this pre-construction area, fish populations generally only found around the occasional one-meter sized rock outcrops. Competition of living space was at a premium. But, add the natural rocky breakwater of Palm Jumeirah and The World and fish populations explode.
I find the female environmentalist’s statement that “artificial reefs and cement barges in the sea are not attracting that many fish” quite interesting. First, the barren pre-existing bottom topography was not good fish habitat thus the fish populations very low. The artificial reefs changed this by providing not only a good protective habitat for developing fish populations but also hard bottom that would provide them with an adequate food source. The algae and encrusting invertebrates that quickly developed on the newly placed breakwaters made from natural rock materials essentially provided the fish with “Condos stocked with food”.
In my decades of underwater reef monitoring and research in southern California, I quickly learned that an incorrectly placed artificial reef was simply a FAD, Fish Aggregating Device. Fish simply re-located from their previous environment to their new, man-made reef condos. This was easy to identify since all the fish were large. They didn’t grow up there, they simply moved there as an adult. In monitoring the fish at the rocky breakwaters of Palm Jumeirah and The World, developing juvenile populations are evident everywhere indicating to me that new fish communities are forming. Through my eyes, I do not see “something disturbing the ecological chain," as claimed by the environmentalist.
In all fairness, I believe that the statements reported by the press and put into print did not fully explain a justifiable environmental concern as a result of not reporting the qualifier. That qualifier was Palm Jebel Ali and the development of a Palm icon 50% larger than Palm Jumeirah over a previously pristine marine coral preserve. The dredging and sedimentation cover in this area will do irreversible damage to the pre-construction rich coral marine environment. Having also made numerous research dives in the area prior to and then again at the start of construction, I can attest to the damage as a result of a fine laver of sediment from dredging and “rainbow-building” operations on the coral. I made a proposal to establish a coral transplant program so that the 20 of so species of unique corals occupy the Jebel Ali Marine Reserve area could be moved and attached to the outer breakwater of Palm Jumeirah. In addition, I proposed BioRock or accretion technology be used to enhance both survivability and coral accelerated growth rates. Preliminary experiments that I conducted with Professor Wolf Hilbertz, co-inventor of BioRock technology, showed promise for application in the Arabian Gulf.
It may be time to re-examine these options relative to The World.