The port, operated on public land by New York Container Terminal, a private company, is one of Staten Island's largest businesses. The company, officials said, has a $53 million payroll and more than 550 employees, unloading around 400,000 shipping containers a year.
But that, company officials and their allies in government say, is not big enough. The terminal, in plans outlined in a series of filings and public forums in the early months of this year, is seeking to expand its 187-acre site with a fourth container ship berth. According to the plans, the $350 million expansion would create more than 300 new jobs. It would also pave over a rare undeveloped swath of North Shore waterfront, and fill in or dredge something even rarer than that: 16.38 acres of coastal wetlands, some of the last in the city.
Because of the wetlands, which are part of a larger area called Arlington Marsh, the project requires approval from the state Department of Environmental Conservation. That could take years to secure. In the meantime, port representatives, local officials and environmentalists are grappling with some daunting questions: Is the waterfront chiefly a natural resource or an economic one? Is there any way to undo decades of environmental damage? And if there is, will anyone will pay for it?
For environmental advocates, the site of the proposed port expansion is at once a vital piece of a dwindling natural resource, and a symbol of how badly the shoreline has historically been mistreated.
Before the arrival of industry there, "Essentially 100 percent of the northwest of Staten Island was salt marsh," said Richard Lynch, staff botanist at the Sweetbay Magnolia Conservancy, a local environmental group, during an interview this month. "We're talking about the last 3 percent of salt marsh that can be filled, when 97 percent of salt marsh at Howland Hook and Port Ivory has already been filled."
Later, on a walk through some of the land, he added, "Staten Islanders can't look at this as just one project. We have to look at it as part of a never-ending process of development."
One virtual certainty is that, if the DEC eventually allows the expansion, it will require the port to make up for filling in the wetlands by creating some public space elsewhere. The company's preference, its president, Jim Devine, said in a telephone interview, is to rehabilitate a city-owned piece of Arlington Marsh directly adjacent to the expansion site, with walking trails, oyster beds and light marshland.
Community Board 1, which represents the area, supports the expansion project, said its district manager, Joseph Carroll. The board had previously favored putting a city sanitation garage on the adjacent marshland, Carroll said, but now would like to see the container terminal rehabilitate part of it and open it to the public. In general, Carroll said, the board favors the expansion because of its economic benefits – assuming there is sufficient mitigation.



