From Sunken Ships to Thriving Ecosystems: A Look at Successful Artificial Reefs

Along the ocean floor, a World War II warship sits in silence — its steel hull now draped in rich corals as an array of fish swarm its passageways. The transformation of war relics into artificial reefs has become critical to marine conservation worldwide. Here’s a closer look at how thriving human-established reefs enhance the ocean environment. 

What Is an Artificial Reef?

An artificial reef is a structure engineered by humans to emulate the function of a natural coral reef. They are usually found in barren underwater regions, creating intricate habitats for corals and oysters to attach themselves to. Various fish species also hide among the nooks and crannies to protect themselves from predators.

Many artificial reefs comprise decommissioned ships, aircraft and subway cars due to their durability and material composition. Today, many companies specialize in material production, design and deployment of artificial reefs made of limestone, concrete and steel. 

There are thousands of artificial reefs globally. Florida, in particular, has one of the most robust artificial reef programs in the United States, with over 4,476 planned projects in the state and federal waters surrounding it. 

The World’s Most Successful and Unique Artificial Reefs

Scientists and engineers at universities, government agencies and nongovernmental organizations have implemented numerous artificial reefs along global coastlines. From Mexico to Jordan and across the U.S., these are some of the most successful — and unique — projects aimed at restoring coral colonies. 

Neptune Memorial Reef in Key Biscayne, Florida

Neptune Memorial Reef is the largest artificial reef worldwide, situated just 40 feet below the water’s surface about 3.25 miles off Miami’s coast. Upon completion, it’ll span 16 acres and provide habitat for 250,000 individuals. Already, the site has attracted scuba divers, marine scientists, fishermen and ocean lovers eager to set their sites on the newly formed habitat. 

This reef stands out for its resilience against South Florida’s tropical storms, while its design features caves and fissures that host a variety of fish and crustacean species.

The Silent Evolution in Cancun, Mexico

The Silent Evolution in Punta Nizuc, Cancun, Mexico, is an underwater art attraction doubling as an artificial reef. Artist Jason deCaires Taylor cast over 500 permanent sculptures made from pH-neutral cement, positioning them downstream for corals to settle easily after spawning.

The installations originally covered 420 square miles of empty seafloor. Yet today, the area is a complex reef structure that supports colonization by marine life, including 2,000 juvenile corals. 

Oriskany Reef in Pensacola, Florida

The Oriskany Reef in Pensacola, Florida, is another massive artificial reef in the U.S. Nicknamed the “Mighty O,” the U.S.S. Oriskany is a 911-foot decommissioned aircraft carrier used during the Korean and Vietnam Wars. 

Scientists sank the Oriskany on May 17, 2006, off the Florida coast in 212 feet of water. Since then, it has supported a tremendous coral reef and become a renowned scuba site for experienced divers.

The Tank in Jordan’s Gulf of Aqaba

Located 6 meters deep in Jordan’s Gulf of Aqaba lies “The Tank” — an artificial reef formed on a sunken M42 Duster tank. The military equipment was dropped to the seafloor in 1999 and expanded into the Underwater Military Museum in 2019.

Today, this popular dive site spans 140 meters from 5 to 28 meters deep and is a flourishing coral ecosystem. The reef — which now contains helicopters, canons and armored vehicles — attracts various marine species, including porcupinefish and lionfish that seek refuge among the decommissioned military hardware. 

Redbird Reef in Delaware’s Indian River Inlet

In 2020, the Reedville ship became part of the renowned Artificial Reef Program in Delaware. It is but one of several recycled ships that the team has sunk on the mid-Atlantic seafloor, and joins 1,350 New York City subway cars and military vehicles to create a stable, thriving coral habitat. 

The structures mimic natural reefs by providing protection and up to 400 times more food than barren ocean seabeds. The Redbird Reef has helped boost local economies, raking in $7 million annually through fishing and recreational activities.

More Than Just Homes for Fish 

Although artificial reefs support abundant marine life, they also provide significant economic benefits and ecological services. For example, with 29% of Americans residing in coastal areas — an increase of 40 million since 1960 — beach erosion poses a significant threat. 

Artificial reefs act as barriers to wave energy, reducing shoreline erosion, while their structures provide surfaces for marine organisms to attach to. This supports biodiversity by delivering new fish habitat.

Economically, artificial reefs generate steady revenue through job creation and recreational fishing. Over the course of 50 years, Georgia has implemented 46 of these reef sites through 70,000 acres. From these projects, the state has generated $38 million to $139.3 million, with returns of $1.60 to $2.40 for every dollar invested in the program. In 2023, its artificial reefs contributed $8.2 million to Georgia’s economy. 

Frequently Asked Questions

How Long Does It Take for a New Artificial Reef to Become a Full Ecosystem?

A coral reef doesn’t form on an artificial system overnight. While a submerged structure develops an algae-based biofilm within weeks — crucial for corals, barnacles and other invertebrates to colonize — a self-sustaining reef could take several years or decades to develop. 

What Makes a Material Good or Bad for an Artificial Reef?

The best artificial reef materials are highly durable, stable and nontoxic. They must withstand heavy currents generated by coastal storms while providing a clean, textured surface for marine organisms to latch onto. 

Likewise, structures should use pH-neutral concrete and thick steel from decommissioned machinery. Poor materials can result in ecological damage. For example, the infamous tire reef in Fort Lauderdale, Florida, degraded in storms and left destruction in its wake. Currently, the Osborne Reef Waste Tire Removal Project is underway to clean up the 1 to 2 million tires by 2028.

Can Individuals Help Support Artificial Reef Projects?

Individuals can support reef-building activities and nonprofit organizations by donating or volunteering. These groups have the expertise and capabilities to deploy artificial reefs effectively within coastal regions.

Most people can contribute through eco-friendly and responsible tourism. If you’re a diver or enjoy fishing, it’s crucial to follow local guidelines and to avoid anchoring on reef structures. Practicing leave-no-trace principles helps protect these habitats even further.  

The Future of Our Underwater Cities

Artificial reefs may not be able to replace natural coral reefs or solve the climate crisis, but they do offer hope for ecological restoration. As science and technology advance, these human-made underwater cities create havens for marine life.