An Oyster in the Storm
Snip:
Crassostrea virginica, the American oyster, the same one that we eat on the half shell, is endemic to New York Harbor. Which isn’t surprising: the best place for oysters is the margin between saltwater and freshwater, where river meets sea. Our harbor is chock-a-block with such places. Myriad rivers and streams, not just the Hudson and the East, but the Raritan, the Passaic, the Kill Van Kull, the Arthur Kill — the list goes on and on — flow into the upper and lower bay of the harbor, bringing nutrients from deep inland and distributing them throughout the water column.
Until European colonists arrived, oysters took advantage of the spectacular estuarine algae blooms that resulted from all these nutrients and built themselves a kingdom. Generation after generation of oyster larvae rooted themselves on layers of mature oyster shells for more than 7,000 years until enormous underwater reefs were built up around nearly every shore of greater New York.
Just as corals protect tropical islands, these oyster beds created undulation and contour on the harbor bottom that broke up wave action before it could pound the shore with its full force. Beds closer to shore clarified the water through their assiduous filtration (a single oyster can filter as much as 50 gallons of water a day); this allowed marsh grasses to grow, which in turn held the shores together with their extensive root structure.
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Once we’d hurled all that against the wild New York oyster, baymen switched to farming oysters. But soon New Yorkers ruined that too. Rudimentary sewer systems dumped typhoid- and cholera-carrying bacteria onto the beds of Jamaica Bay. Large industries dumped tons of pollutants like PCBs and heavy metals like chromium into the Hudson and Raritan Rivers, rendering shellfish from those beds inedible. By the late 1930s, oysters in New York and all the benefits they brought were finished.
http://www.nytimes.com/2012/10/30/opinion/an-oyster-in-the-storm.html