Oysters Help Filter Pollution in New York Rivers
Kate Orff sees oysters as an urban change agent. The New York City architect is promoting the bivalves to the role of pollution mitigators in some of the city’s nastiest rivers. She outlined her idea in a TED Talk in 2010 and now her theory is taking hold.
Long from being able to eat the oysters from New York estuaries as people once did scientists are noticing marked improvement, namely the fact that the oysters themselves are surviving from year to year.
When pollution reached a critical point years ago, the oysters died off. After that happened they couldn’t act as natural filters and the pollution problem in area rivers became much worse.
Now Dr. Orff, who teaches architecture (or should we say oyster-tecture?) at Columbia University is planting the idea that cities can reclaim polluted waters by sinking oysters in them to slurp up pollution and spit out clean water.
Mark Kurlansky is part of a regional water clean up effort using oysters and the author of The Big Oyster: History on the Half Shell. He says “There are so many reasons why the replanting of oysters in New York Harbor is important that it is difficult to list them all.”
First, he says, it is a part of the history and of New York City but a long forgotten part since the last bed was shut down in 1927. Before that he says, “If someone said they were going to New York, the most likely response was ‘enjoy the oysters.’ They were sold on street corners in elegant restaurants, in the slums, and in all night out door markets.”All five boroughs had oyster beds, which have gradually disappeared as increasing pollution destroyed them. The harbor was full of millions of oysters and Kurlansky says the goal of the Oyster Restoration Research Partnership is to bring oysters back and in the process to restore and celebrate New York history. The oyster charge is being led by the Hudson River Foundation, the US Army Corps of Engineers, NY/NJ Baykeeper, the New York-New Jersey Harbor Estuary Program, the Urban Assembly New York Harbor School and the New York City Department of Environmental Protection
Kurlansky feels that when the harbor became too polluted for oysters and for people “We lost our connection to the sea. New Yorkers too easily forget that they live on the sea and they live in a magnificent estuary that needs to be protected.” For him having thriving oyster beds “celebrate the accomplishments of the past thirty years in cleaning up New York harbor and remind us that this is something we must continue to fight for–that there can be no back sliding on environmental protection.”
And fourth, he says, “The oysters are good for the water filtering out natural impurities and keeping the water clean. But they can’t clean up PCBs and heavy metals and until that is done we will not be able to eat these oysters and so they remind us of the work that is yet to be done.”
Ray Grizzle explains how oysters naturally filter water. He says, “When they feed the upper valve raises up and they have ciliated gills — these sheets of tissue — that pump water through them.” He says as the water passes through the gills there is a gas exchange just like in fish. But unlike fish the particles in the water get filtered out as well. In essence the oyster is absorbing all the pollution in its surroundings and pumps out fresh, clean water.
The University of New Hampshire benthic ecologsit travels around planting oysters in polluted waters. In 2006 he dropped some baby oysters in Great Bay in New Hampshire and waited to see what would happen. After a big storm, the oysters multiplied five-fold and have escaped a disease that decimated their numbers in the 1990s. By 2008 there were over 250,000 oysters in an area known for oysters.
Grizzle says oysters are not just for eating. They are good for the environment, filtering as much as 50 gallons of seawater a day. They also tend to grow into tight, convoluted reefs which, he says shelter small fish and crabs improving the overall health of the bay.
He’s teamed up with landscape architect Orff to see what can be done in New York. And preliminary results are looking good. On a recent trip to check oyster health near Manhattan, Grizzle found reproducing oysters that are making their home in polluted waterways.
Grizzle says, “We’ve got oysters that look really good and healthy–that’s the really good news.”
And Orff is confident that she can help turn one of the nation’s most polluted stretches of water — the Gowanus Canal — into an attraction.She says, “Oyster-tecture was conceptualized as setting into motion a system where baby oysters could be seeded in the Gowanus and flow out and build up and develop on the Bayridge Flats which we are calling Palisades Bay Reef.” She explains that there is a cycle that gets set into motion starting with baby oysters which lead to reef building and ultimately to cleaner water.
The Gowanus Canal is a Superfund site in Brooklyn.
Grizzle says, “The thing about oyster restoration that is different from just about any efforts that I know of is it has multiple benefits — the habitat quality, it improves habitat for fish and bird species and it also provides water filtration. And that will affect water quality.”
In an effort to restore New York Harbor the whole community is getting involved. Kate Boicourt is an oyster gardener and restoration coordinator of the NY-NJ Harbor Estuary Program which is part of the restoration project. She says, “Oyster gardening is a system of citizen science that’s been used up and down the east coast for a while, engaging schools, individuals and community groups in restoration work.”
And it’s not just kids in schools. Oceanographer and Hudson River Foundation project manager Jim Lodge says, “It’s not just high schools that are getting involved, but community groups, senior citizen centers and preschools.” He calls the model very powerful because it gets people involved at multiple levels, all while making a direct connection between the average citizen and the estuary.
Orff shares her fondness for her oyster-tecture idea. “The core idea is to harness the biological power of mussels, eel grass and oysters — species that live in the harbor. And at the same time harness the power of people who live in the community towards making change now.”
And if she gets her way, Orff says that the people of Brooklyn will be eating oysters out of the Gowanus Canal by 2050. But right now those oysters are working hard to filter almost 100 years of pollution.