New Jersey sank 397 obsolete army tanks and armored vehicles from 1994 to 1997 in 40 to 140 feet of water; a five-year study found 432,000 animals of 145 species per square metre of reef habitat

There is a graveyard of Cold War equipment, forgotten by most Americans, buried somewhere under 40 to 140 feet of Atlantic Ocean off the Jersey Shore. Between 1994 and 1997, the US Army and the New Jersey National Guard sank 397 obsolete tanks, armored personnel carriers, and crane vehicles into the ocean, on purpose. That is not an inadvertent war casualty, but a project deliberately designed as a fisheries project, known as Operation REEFEX.

The story is even more bizarre and, simultaneously, more wholesome: the tanks worked. According to New Jersey Division of Fish and Wildlife colonization studies referenced in the state's 2004 draft Artificial Reef Management Plan, biologists recorded an average of roughly 432,000 marine animals across 145 species, with a biomass of close to 128 pounds, per square metre of reef habitat surface, a figure drawn from small, specially built experimental habitats (wire boxes packed with fiberglass panels, whelk shells, and steel, concrete, rock, and tire test plates) that biologists placed on the sea floor at reef sites and later retrieved for lab analysis, not from material scraped directly off a tank's hull. It's a measure of what a square metre of colonized reef surface can hold, not a claim that every square metre of an actual tank was carrying that many animals.

From battlefield to barnacle city


The tanks, the majority M-60s and M-551s as well as M-113 armored personnel carriers, were barged out to sea and then pushed off the deck after being hauled out of bases in Georgia and Alabama with fuel, oil, batteries, and other hazardous fluids removed at Fort Dix. New Jersey wasn't doing anything particularly new here; since 1984, the state has been dumping rock, concrete, old subway cars, and decommissioned ships to compensate for a common issue. The state's ocean bottom is mostly sand and mud, nothing for the fish to call home that resembles hard surfaces to hide, feed, and breed on.

Thus, steel hulls proved to be good places to reside in. Almost right away, mussels, barnacles, anemones, crabs, worms, and baby fish came in and took up residence in the holes and cracks of the tanks. The same state colonization research found that reefs of this kind supported hundreds of times more biomass than the surrounding bare sea floor nearby, a finding from studies conducted in the late 1990s and early 2000s, well before the present day.

Why should this matter

From Alabama to California, military hardware, ships, and even subway cars have been converted into artificial reefs, which are now a common fisheries management tool along the entire U.S. coastline. It's been decades since the federal government had to develop a program to regulate artificial reefs, and they did so because states were finding that "waste" materials could be utilized as fish habitat if they were cleaned and installed in the appropriate fashion. For this one weird example, people who were raised on the belief that we are causing ecosystem damage were given a counterexample: a military dump that is now an aquatic nursery.

The part you ought to know about and the takeaway

Industrial activities that involve the dumping of heavy equipment into the ocean do not necessarily equal clean and harmless fisheries just because fish can be seen later. A 2012 Scientific American article on artificial reef programs, now well over a decade old itself, reported that the most common problems with using military and industrial scrap for reefs were untouched toxic material leaching into the water, structures breaking apart and drifting into natural reefs, and open questions about whether new marine life actually grows there or simply relocates from other reefs. New Jersey's tanks were decontaminated prior to deployment, a process that may not be done by all state programs, but “we cleaned it first” has sometimes been more of a promise than a reality in other parts of the country.

New Jersey's tank reefs do not prove that dumping old equipment in the sea is of no detriment. They are examples of how a combination of adequate preparation, the right permits, and sustained long-term monitoring turned one state's army surplus issue into a flourishing underwater community. But that should not sway your opinion that all rusted hulks deserve a free trip to the bottom of the sea.