Usually, dumping metal into the ocean is a bad thing, but for once throwing disused items into the sea is working out for the greater good.Over 2,500 New York subway cars have been used to create an underwater reef for crustaceans and fish in the Atlantic. Over a period of three years, photographer Stephen Mallon of the Front Room Gallery captured images of the carriages being put in place, and his photos now are being shown in a solo exhibition in New York. "I had read about the subway cars being dropped into the Atlantic, but I thought the project was over," said Mallon..... Once the subway cars had been decommissioned, they were cleaned and every part of them that could be removed -- seats, straps and wheels -- was recycled or sold. Then the carriages were stacked onto a barge, which transported them to the dropping point.....
These structures mean there is now 400 times as much food per square foot for fish to eat.
Some cars have also been dropped in Georgia, although not all site locations are disclosed to the public, as some are used for ecological studies.The project, run by New York's 
, ended in 2010. But the carriages have a new life beneath the sea. "We've been monitoring the carbon steel subway cars and they are holding up well," said Jeffrey Tinsman, artificial reef program manager at the Delaware Department of Natural Resources and Environmental Control.
Source: http://www.cnn.com/2015/02/26/world/subway-cars-coral-reef/