In New York, shellfish lands are defined as all tidal or saline waters within the marine district and the lands lying thereunder, including such lands which are exposed at low tide. In Connecticut, shellfish growing areas are defined as any area that supports or could support the growth and/or propagation of molluscan shell stock (live clams, oysters, mussels and scallops in their shell). Both states reevaluate shellfish areas for improvements or degradation of water quality and status of pollution sources, and to determine whether it’s classification for harvesting species should be upgraded or downgraded..
Approved shellfish acreage indicates whether water quality in embayments and tidal rivers and in open waters near the shore are able to support the harvesting of shellfish for human consumption.
In Connecticut, more than 6,000 acres of approved growing areas were downgraded from 2010 to 2011, adding to a decline of more than 16,000 acres that occurred from 2005 to 2006. Resource managers cited as a reason increased coastal development bringing more impervious surfaces such as sidewalks and rooftops. After heavy rains, stormwater runoff carries pollutants such as harmful bacteria from animal waste onto these hard surfaces and into storm drains and streams that end up in coastal waters. In 2010, however, Connecticut added an additional 950 acres of approved shellfish acreage in offshore waters closest to Westport thanks in part to improvements in water quality along the Norwalk River. Upgrades in the wastewater treatment plant and the removal of some lllegal sewage connections into the river contributed to the improvements. In 2011, citing the positive results of sanitary surveys, water quality monitoring and shellfish tissue testing, NYSDEC certified and reopened approximately 2,500 acres of shellfish beds for shellfish harvesting in outer Hempstead Harbor and Long Island Sound. This area had been closed to the harvest of shellfish for more than 40 years.