One of the keys to thriving marine communities is "structure": the more
complex the substrate, the more nooks and crannies and different kinds
of habitat are created for things to live on and in. Artificial "reefs",
when done propoerly so as to not cause more problems because of
polllution from oil and such, are a haven for marine life, and are
facilitating the creation of vibrant, thriving undersea communities
(with lots of molluscs!!) in many parts of the world. This example in
Delaware is one of the best success stories:

http://www.nytimes.com/2008/04/08/us/08reef.html?_r=1&th&emc=th&oref=slogin

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
<http://topics.nytimes.com/top/news/national/usstatesterritoriesandpossessions/delaware/index.html?inline=nyt-geo>
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.

The reef, named after New York City’s famous Redbird subway cars, now
supports more than 10,000 angler trips annually, up from fewer than 300
in 1997. It has seen a 400-fold increase in the amount of marine food
per square foot in the last seven years, according to state data.

Mr. Tinsman said his department was doing everything it could to expand
the capacity, noting that last year, when subway cars were unavailable,
he sank a 92-year-old tugboat and the YOG-93, a 175-foot decommissioned
Navy tanker built in 1945 for the planned invasion of Japan. Fifty
subway cars are due this month, he said.

“The secret is out, I guess,” said Michael G. Zacchea, the Metropolitan
Transit Authority official in charge of getting rid of New York City’s
old subway cars.

Mr. Zacchea added that Delaware’s prospects for expanding the reef
looked grim because New York State has said it wanted all of the city’s
retired subway cars once the United States Army Corps of Engineers
updates the state’s reef permit this summer. Mr. Zacchea said he would
soon stop shipments out of state, saving perhaps $2 million in transport
costs. As a good faith gesture, the city probably will provide about 100
cars to Delaware, Maryland, Virginia and New Jersey before out-of-state
deliveries are halted.

While New York State works to get its permit in place, other states are
pushing hard to get what they can from the city, Mr. Zacchea said.

Last month, for example, New Jersey, which stopped taking the cars in
2003 because of environmental concerns, asked the city for 600 of them.

Tim Dillingham, the executive director of the American Littoral Society,
a coastal conservation group based in Sandy Hook, N.J., said natural
rock and concrete balls were far safer and more durable materials for
artificial reefs.

“Those materials also cost more, and we’re sensitive to the realities of
budget crunches in many states,” Mr. Dillingham said.

The American Littoral Society and other environmental groups opposed the
use of the Redbird cars because they have small levels of asbestos in
the glue used to secure the floor panels and in the insulation material
in the walls.

State and federal environmental officials approved the use of the
Redbirds and other cars for artificial reefs in Delaware and elsewhere
because they said the asbestos was not a risk for marine life and has to
be airborne to pose a threat to humans.

Mr. Dillingham said his group had pushed New Jersey to use only New York
City’s cars, which have only stainless steel on the outside, contain
less asbestos and are more durable. Delaware, which oversees nine
artificial reef sites in state waters and five, including Red Bird Reef,
in federal waters, was the first state to get subway cars from New York
City, in August 2001.

In the last several years, the reefs have drawn swift open-ocean fish,
like tuna and mackerel, that use the reefs as hunting grounds for
smaller prey. Sea bass like to live inside the cars, while large
flounder lie in the silt that settles on top of the cars, said Mr.
Tinsman, the Delaware official.

States have experimented with other types of artificial reef materials,
including abandoned automobiles, tanks, refrigerators, shopping carts
and washing machines.

Mr. Tinsman particularly favors the newer subway cars with stainless
steel on the outside to create reefs. “We call these the DeLoreans of
the deep,” he said.

Subway cars in general, he said, are roomy enough to invite certain
fish, too heavy to shift easily in storms and durable enough to avoid
throwing off debris for decades.

“The one problem I see with them,” Mr. Tinsman said, “is that just like
the DeLoreans, there are only a limited number.”

- From a Sunny Spring Day in New Scotland,
Ross Mayhew.

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