Why artificial reefs made of old subway cars are great for fish
Artificial reefs provide 400 times as much food for fish as nearby sandy bottom areas, says project manager
Windows and doors are key for subway cars, to allow people to enter and exit quickly and to see where the train is going — and as it turns out, all those openings are fantastic for fish, too.
Off the coast of Slaughter Beach, Del., is a spot called the Redbird Reef. It's named after the decommissioned New York City Redbird subway train cars, noted for their red paint, that make up much of the reef.
While the reef site started to take shape in 1996, it grew substantially from 2001, when New York City donated more than 600 old subway cars to Delaware.
"They call it the underwater train wreck. Sometimes you'll be in different places and it will look different," said Jeffrey Tinsman, the project manager for Delaware's artificial reefs, in an interview with Brent Bambury on Day 6.
The subway cars were pushed overboard in groups of 30, according to Tinsman.
"And so there's no telling how they're going to land. Sometimes they land with one end of the car up on to an adjoining car," he explained.
Before the cars are dumped into the ocean, all of the glass, seats and signs are removed, along with the wheels and any petroleum products like grease and oil.
The remaining frame of the car measures about 15.5 metres (51 feet) long by 2.7 metres (nine feet) wide, with plenty of gaps where the doors and windows used to be.
A big buffet for fish
"That allows water flow to move through the car and ... you get good water quality and you get the larvae of these invertebrates, like blue mussels that are attached to the whole surface of the car almost like a carpet," said Tinsman.
"There are about 30 or 40 other species of invertebrates, shrimp, crabs and worms and so forth, that are all associated with that blue mussel community. And in total, there's about 400 times as much food for fish per square foot as there is in the natural sand bottom," he said.
That natural sand bottom on its own doesn't provide a great habitat for fish.
"In the mid-Atlantic here we kind of got the short end of the habitat stick when they were handing out habitat," said Tinsman. The "featureless" bottom doesn't offer a lot of protection for slow-moving fish like the tautog (also known as the blackfish), but the artificial reefs provide plenty of hiding spots and food for the species.
"I think tautog are a good example of a fish that is definitely benefiting from this reef program," he said.
Warming oceans are causing coral reefs around the globe to bleach. Sometimes the corals can recover from a heat wave, but more frequently the corals are dying. So the artificial reefs offer hope that habitat for fish and other ocean dwellers can be created.
Concrete, military vehicles, ships make up reefs
Delaware has 14 artificial reefs, in Delaware Bay and along the Atlantic coast in the south of the state. Subway cars make up just a part of the whole ecosystem.
To build the reefs, the state has used 89,000 tonnes of concrete products, 9,000 tonnes of ballasted tire units, 86 decommissioned military vehicles as well as retired ships.
One particular vessel, the retired Navy destroyer USS Arthur W. Radford, is a site that Tinsman says he dives regularly.
"That is almost exactly like diving a World War II wreck — except, of course, they are not degraded at this point; they haven't been down there for 70 years yet," he said.
The sinking of the 563-foot Arthur W. Radford in 2011 was a three-state effort between Delaware, New Jersey and Maryland. The now-sunken ship is located nearly equidistant from ports in all three states, Tinsman explained.
But not every material makes a good candidate.
"You would not want to put an automobile body out there that's going to rust away in two years because it costs the same amount as putting concrete out there which is going to last a thousand years," he said.
For his part, Tinsman says the subway cars are among the best reef materials he's ever sunk, but he's always keeping an eye out for new opportunities.
"I don't have occasion to ride too many trains but, believe me, I always have that in the back of my mind when I go by a construction site on a highway and there are piles of culvert pipe and so forth. I'm always in the reef building mode," he said.
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