SLAUGHTER BEACH, Del. - Sixteen nautical miles from the Indian River Inlet and about 80 feet underwater, a building boom is under way at the Red Bird Reef.
One by one, a machine operator has been shoving hundreds of retired New York City subway cars off a barge, continuing the transformation of a barren stretch of ocean floor into a bountiful oasis, carpeted in sea grasses, walled thick with blue mussels and sponges, and teeming with black sea bass and tautog.
"They're basically luxury condominiums for fish," Jeff Tinsman, artificial reef program manager for the Delaware Department of Natural Resources and Environmental Control, said as one of 48 of the 19-ton retirees from New York City sank toward the 666 already on the ocean floor.
But now, Delaware is struggling with the misfortune of its own success.
Having planted a thriving community in what was once an underwater desert, state marine officials are faced with the sort of overcrowding, crime and traffic problems more common to terrestrial cities.
The summer flounder and bass have snuggled so tightly on top and in the nooks of the subway cars that Mr. Tinsman is trying to expand the housing capacity. He is having trouble, however, because other states, seeing Delaware's successes, have started competing for the subway cars, which New York City provides free.
Crisscrossing over the reef, commercial pot fishermen keep getting their lines tangled with those of smaller hook-and-reel anglers, and the rising tension has led the state to ask federal marine officials to declare the area off limits to large commercial fishermen.
As the reef has become more popular, theft and sabotage of fishing traps and pots has more than doubled in the last several years, said Capt. David Lewis of the Delaware Bay Launch Service. "People now don't just steal the fish inside the pots out here, they've started stealing the pots, too," he said.