Monday, March 17, 2014

Great Article on Cities and the Sea Discusses Dunes and Oysters

There is a terrific article in Orion Magazine talking about managing development on shorelines. We excerpted the portion on oysters in NYC below. But, We encourage you to check out the full article here.

Now, New York City waters are cleaner than they’ve been in decades, and spat—the little larvae of oysters—are floating about, seeking out some substrate to latch on to so they can grow.
“There are oyster larvae,” says landscape architect Kate Orff.  “There’s just no place for them to land. So there are these babies, but then . . .” She pauses and makes a long downward whistle indicating failure. “I get depressed about this, as a mom of two.”
Orff has proposed bringing back New York City’s lost oyster reefs—which could naturally help shield the city from future storm surges—in a project called Oyster-tecture. We meet at a round table in the kitchen of her SCAPE Studio offices on Lower Broadway, with a foggy morning view across Manhattan to the Hudson River.
Her idea is to make a home for the oyster orphans, starting in Brooklyn’s Gowanus Canal, one of the most polluted waterways of the city. Piers are already in place; cages will be lowered into the water that are filled with fuzzy rope, providing lots of surface area for spat to land. (The cages are to keep hungry New Yorkers from prematurely harvesting oysters that won’t be suitable for human consumption for years to come.) She was thrilled when she heard Governor Cuomo give a shout-out to the bivalves after the storm: “It came out of his mouth—‘We need to be thinking about oyster beds’—and I’m like, yes, that’s the goal!”
Orff advocates dredging and filling waterways in a way that supports underwater ecosystems instead of destroying them. “I think a big part of this is thinking about it holistically,” she says. “You can use dredging and filling in a cut-and-build concept throughout the harbor to create a new set of edges and cross-sections that can become armatures for habitat.” As the oysters build upon themselves, making reefs out of their own shells, they work continually to clean the waters, acting as natural filtration systems.
To consider the return of oyster reefs to New York is to explore the bathymetry, or underwater topography, of the waters that surround the city’s islands. Orff explains the mechanics, but it’s as much a history lesson.
“There was once this historic 3-D mosaic of underwater bathymetry, which included barrier islands and oyster reefs and shallower shoal areas that make a threshold into the inner harbor,” she says, using a marker to show how the stretch of Sandy Hook on the Jersey Shore wants to reach up and connect with Coney Island in a series of channels and shoals. If the land mass was permitted to form again, it would help diminish the impact of sea surges. One hard passageway could allow a steady shipping channel. “See this signature?” she taps her marker on the area between Staten Island, Brooklyn, and New Jersey. “This whole area was once shallows, back in 1766, fortified with layers of ecological systems.”
Orff isn’t the only person in the city thinking about oysters. Marit Larson, the NYC Parks Department’s director of wetlands, is working on oyster restoration on the north side of the city. She says that, increasingly, oysters have been showing up on tires and concrete rubble in the Bronx River. In 2006, the Parks Department started designing artificial reefs to supplement the river’s substrate; now they’re working with partners that include NY/NJ Baykeeper and New York Harbor School, which trains low-income kids in hands-on maritime stewardship as they dump 120-ton loads of shells into an area where the East and Bronx rivers converge. One survey taken just before Sandy struck found more than eleven thousand oysters along a mile-wide swath of water. Last summer, students relocated another 100,000 farm-raised spat to the growing reef.
When referencing historical patterns, Kate Orff refers repeatedly to something called the Ratzer Map. In 1766, ten years before the rebellious colonists unshackled their new nation from the British empire, cartographer Bernard Ratzer was trolling the New York Harbor, recording its curves and depths. His sepia-toned map now hangs at the Brooklyn Historical Society, a memory of the city’s once-flourishing natural infrastructure that, if brought back to life, could help mitigate the type of damage experienced during an event like Sandy.
Orff’s pen sweeps across her drawing. “This is a diagram of an ideal world of nature’s protectors. You have layers and layers of barrier dunes, and then vast tracts of wetlands. Wetlands don’t make sense if you have a building and only a little wetland. Wetlands only make sense if they are extensive, so they can really dissipate wave energy.”
Of course, efforts like these can only do so much to counteract the effects of climate change. But if combined with a comprehensive rebuilding of New York’s natural features, they could make a real impact. “There is literally nothing that could have stopped the Sandy surge,” Orff says. “But hard and soft infrastructure solutions could be combined in a win-win-win scenario that would revitalize the harbor landscape, clean the water, and begin to address coastal protection.”

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