Green Daily

Off the coast of Delaware, 714 retired New York City subway cars lay buried at the bottom of sea, making up what is known as the Red Bird Reef. The artificial reef is home to tons of fish, plant life and coral, and for awhile has been a successful endeavor. (Artificial reefs are usually installed to enhance recreational fishing and diving, as well as increase wildlife habitats. They are also used to control beach erosion).

But lately, The New York Times reports, Delaware's reef is suffering. Other states are now vying for the New York Subway cars to create their own reefs, and there are so many fish who call the spot home that the cars are starting to get a little crowded, kind of like the F Train at rush hour.
Other problems include fishermen who fish at the reef getting their lines entangled with one another, and people stealing fish and fishing traps from the site. And some environmental groups are angry because there is a small amount of asbetos in the glue used on the train cars. But Delaware officials say they prefer subway cars to other materials that can be used for reefs, like cars, tanks, refrigerators, shopping carts and washing machines.

Interestingly, when the cars were unavailable, the reef's program manager says a tug boat and even a decommissioned Navy tanker were sunk and used as reefs.