Redbird Reef, located 24 metres deep off the coast of Slaughter Beach, Delaware, contains hundreds of retired subway cars, military tanks, and vessels that transformed a sandy seabed since 1996.
The Origins of Redbird Reef
Given that roughly three million sunken ships may lie on the ocean floor, shipwrecks represent the most frequent variety of artificial reef. However, boats are not the only structures deployed to build new aquatic habitats. Decommissioned subway carriages also rest beneath the waves.
Redbird Reef stands as the most famous of these submerged subway reefs. Situated approximately 24 metres underwater near Slaughter Beach, Delaware, its development commenced in 1996 as a component of an extensive initiative utilizing recycled components to establish new ecosystems across multiple artificial reef locations.
Materials Deployed Across Delaware’s Seabed
The Delaware Department of Natural Resources and Environmental Control (DNREC) outlines the scale of the project on its website. The inventory features upwards of 1,350 retired subway cars, more than two million tons of rock, 100,000 tons of concrete, 86 tanks and armoured personnel carriers, and 32 retired vessels spanning lengths from 40 to 653 feet.
The New York subway cars serve as the reef’s star attraction. Hundreds of retired Redbird subway carriages—which lend their name to the site—were scuttled after any hazardous materials, doors, and windowpanes were removed. Additional carriages were sunk in other areas of the Delaware artificial reef programme and beyond in other states. Alongside the subway cars, tugboats, trawlers, barges, warships, and a cruise ship spend their retirement as part of the area’s artificial reefs.
Marine Life and Economic Impact
Prior to the establishment of the Delaware Artificial Reef Programme, the region consisted primarily of a sandy seabed. Today, the accumulated reef structures attract lots of fishes, including sea bass, tautog, triggerfish, flounder, tuna, and sharks.
As noted in the 2023–4 Delaware Reef Guide, the artificial reef initiative generates approximately six million US dollars annually for the regional economy via the recreational fishing and diving activities it supports.
Storm Damage and Structural Risks
Despite Redbird Reef’s fame, not everyone is fully convinced of its positive environmental impact. A 2016 AGU paper examined how major storms have impacted the structures, discovering that 2012’s superstorm Sandy damaged or destroyed eight subway cars. Furthermore, storm Jonas rotated a previously static 47m long Navy barge nearly 60 degrees in 2016.
Fragments originating from damaged structures can become problematic. Once destroyed or collapsed by waves, the subway cars transition from providing positive structural relief and beneficial habitat above the surrounding seabed to being reduced to scattered low relief marine debris, the study authors write.
Experts view this occurrence as a warning example, highlighting the necessity to thoughtfully evaluate the components chosen for artificial reef construction and their potential vulnerability to storms, waves, and currents. A parallel case occurred with the Osborne Reef in Florida in the 1970s. That project was supposed to help recycle disused tyres but ended up as an environmental catastrophe, requiring cleanup projects decades later as a stark reminder of the importance of proper research and planning before putting things into the ocean.
