By Edward Fischer

The loss of natural reef systems is a threat to both biodiversity and ecosystem services on a global scale. In many cases, the loss of these reef ecosystems is a direct result of anthropogenic activities, which, is in fact, one of the primary themes of the environmental studies field course that I am currently enrolled. Now that I’ve experienced some of these marine environments first-hand, I’ve found myself wondering if human impact, particularly artificial reef habitats, can play a constructive role in shaping these environments?

Graphical comparison of attraction-production hypotheses. Adapted from ICES Journal of Marine Science.

Graphical comparison of attraction-production hypotheses. Adapted from ICES Journal of Marine Science.

Over the past 300 years, artificial reefs have been employed for the purpose of promoting marine life [1]. In particular, their primary purpose was to create fisheries for commercial interests, but recently governments and environmental organizations have adopted their use. Unfortunately, most data into the effects of artificial reef deployment is lacking since research rarely begins prior to construction [2]. Post-hoc research is important, but has not been able to address the fundamental questions regarding global impacts or local impacts on natural reefs.

Concerns associated with artificial reefs fall mainly into three categories: 1) toxic chemicals being leached into the water, 2) artificial materials coming loose and damaging natural reefs, and 3) whether artificial reefs attract biota that would otherwise contribute to nearby natural reef systems.

The first and second concerns are addressed by the National Artificial Reef Plan, which requires the EPA to grant permits prior to the deployment or dumping of materials for an artificial reef since 19853. The third concern is more controversial as the overall effects of artificial reefs (e.g., source vs. sink) are hotly debated amongst the scientific community.

Reef Ball successfully growing coral in Indonesia. Photo courtesy of www.reefball.org

Reef Ball successfully growing coral in Indonesia. Photo courtesy of www.reefball.org

Proponents of artificial reef systems believe that reef habitat is the limiting factor for growth. For example, habitat restoration and reef deployment is believed to improve biodiversity on a local, and even global level.

Many types of artificial reef methodologies are in place today, which include the use of Reef Balls (see image above), as well as the scuttling of decommissioned ships to create habitat. In fact, the largest artificial reef on the world (the decommissioned aircraft carrier Ex-U.S.S. Oriskany) lies off the coast of Florida[3]. Unfortunately, ships and other discarded materials can bring with them a variety of toxic chemicals and other environmental issues that often require expensive cleanup efforts.

Bulldozer at Seabee Junkyard. (Photo by Jim Haw)

Bulldozer at Seabee Junkyard. (Photo by Jim Haw)

This week, while on Guam, I had the opportunity to dive on an artificial reef (of sorts) in Apra Harbor known as Seabee Junkyard, which was created by the U.S. Navy Construction Battalion to discard of equipment after World War II. Since the placement of the ‘junk’ (more than six decades ago) there has been some coral growth and a fair number of reef fish call the site home.

Thus, I return to my original question regarding the environmental value of artificial reefs. Based on my recent experiences I would say the answer to this question is “maybe.” The fact of the matter is that nearly 10% of earth’s coral reefs have been destroyed and another 60% are in danger [4] -- so maybe there is something to the concept of artificial reefs after all.

For example, artificial reefs, “provide corridors of a sort, allowing smaller fish to safely migrate from one natural reef to another, instead of just crossing a huge empty expanse where they might get gobbled up,” said Mark Perry, executive director of the Florida Oceanographic Society [5]. With more research, the effects and processes occurring with the deployment of artificial reefs will become more effective, and, with luck, will be a positive impact we have on the world’s oceans. In the meantime, the conservation of our existing coral reefs should be paramount.

About the Author: Edward Fischer is a junior working toward a bachelor’s of science in Environmental Studies in the USC Dana and David Dornsife College of Letters, Arts and Sciences. He has been diving since 2007 and hopes the program in scientific diving will provide the tools to learn how to protect and harness ecosystem services.

Sources Cited:

1. Choi, Charles Q. "Concern Lingers on Success of Artificial Reefs." LiveScience.com. 27 Dec. 2007. Web. 14 May 2012.

2. Wilding, T. "Evaluating Artificial Reef Performance: Approaches to Pre- and Post-deployment Research." ICES Journal of Marine Science 59 (2002): S222-230. Web. Rep. National Artificial Reef Plan (As Amended). United States Department of Commerce National Oceanic and Atmospheric Administration, Feb. 2007. Web.

3. Olsen, Erik. "Out of Commission Above Water, but Not Below It." 18 Aug. 2008. The New York Times. The New York Times, 19 Aug. 2008. Web. 14 May 2012.

4. "Coral Reefs." Coral Reefs. Exploring The Environment. Web. 14 May 2012.

5. Choi, Charles Q. "Concern Lingers on Success of Artificial Reefs." LiveScience.com. 27 Dec. 2007. Web. 14 May 2012.

Editor’s note: Scientific Research Diving at USC Dornsife is offered as part of an experiential summer program offered to undergraduate students of the USC Dana and David Dornsife College of Letters, Arts and Sciences. This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island and throughout Micronesia. Students investigate important environmental issues such as ecologically sustainable development, fisheries management, protected-area planning and assessment, and human health issues. During the course of the program, the student team will dive and collect data to support conservation and management strategies to protect the fragile coral reefs of Guam and Palau in Micronesia.

Instructors for the course include Jim Haw, Director of the Environmental Studies Program in USC Dornsife, Assistant Professor of Environmental Studies David Ginsburg,, SCUBA instructor and volunteer in the USC Scientific Diving Program Tom Carr and USC Dive Safety Officer Gerry Smith of the USC Wrigley Institute for Environmental Studies

Previously in this series:

Catching Up with Scientific Diving at USC Dornsife: Surfgrass Monitoring at Catalina

Catching up with Scientific Diving at USC Dornsife: The Robot Submarine

Catching up with Scientific Diving at USC Dornsife: Diving into the Aquarium of the Pacific

USC Dornsife Scientific Diving: Moving Forward to Guam and Palau 2012

USC Dornsife Scientific Diving: Finding My Career Through This Course

USC Dornsife Scientific Diving: The Devaluation of Ecosystem Services

USC Dornsife Scientific Diving: Why USC Dornsife was the Right Decision For Me

USC Dornsife Scientific Diving: Why Experiential Learning is Vital to Academic Life

USC Dornsife Scientific Diving: My Walden South of Los Angeles

USC Dornsife Scientific Diving: Crown-of-Thorns Outbreaks and Anthropogenic Pollution

USC Dornsife Scientific Diving: The International Policy Rationale for the Military Buildup on Guam and Some Environmental Drivers

USC Dornsife Scientific Diving: Marine Ecology from Antarctica to Micronesia

USC Dornsife Scientific Diving: Palau Water Supply

USC Dornsife Scientific Diving: The Contributions of J. S. Haldane to Dive Safety

USC Dornsife Scientific Diving: Human Impacts on Mangrove Forests

USC Dornsife Scientific Diving: Global Sea Cucumber Fisheries

USC Dornsife Scientific Diving: Palauan Mermaids

USC Dornsife Scientific Diving: The California Spiny Lobster

USC Dornsife Scientific Diving: The Invasion of the Coconut Rhinoceros Beetle

USC Dornsife Scientific Diving: The Coconut Crab in Guam

USC Dornsife Scientific Diving: The Ordot Dump and Layon Landfill

USC Dornsife Scientific Diving: Marine Ecosystem Based Management

USC Dornsife Scientific Diving: The Navy Dive Tables

USC Dornsife Scientific Diving: Entangled in the Excitement of Every New Day

USC Dornsife Scientific Diving: Economic Effects of the Revised Military Buildup in Guam

USC Dornsife Scientific Diving: The Guam and Calayan Rails

USC Dornsife Scientific Diving: Chamorro Women and the Spanish

USC Dornsife Scientific Diving: Diving into Apra Harbor’s Western Shoals and CB Junkyard