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Research & Monitoring

Status & Trends

LISS Ecosystem Targets and Supporting Indicators

Approved Shellfish Areas

Upgrade 5% of the acreage currently restricted or closed for shellfishing by 2035 from a 2014 baseline.

Approved Shellfish Acreage (CT)
ApprovedConditionally ApprovedRestrictedProhibited
Approved Shellfish Acreage (NY)
Percent to Goal
YearCT upgrades (acres)NY upgrades (acres)Net CT Total (acres)Net NY Total (acres)Net Total (acres)Percentage to the 2035 Goal (upgrade 17,017 acres)
2014 (baseline)000000

Status and Trends

In order to meet the 2035 target, over 850 of the closed or conditionally closed acres would need to be upgraded each year (17,017 total acres by 2035). In 2015,  371 acres were downgraded in New York and in 2017 39,602 acres in Connecticut were administratively downgraded. Therefore, this target is behind schedule.

In Connecticut, the vast majority of classification changes in 2014 were administrative in nature, rather than resulting from water quality issues impacting shellfish growing areas.  For example, there were a number of classification downgrades from Restricted to Prohibited in portions of rivers that are not active shellfish areas and are not able to be sampled at the frequency necessary for the areas to remain active growing areas and resulted in a large reclassification of 5,531.81 acres from Conditionally Approved: Administratively Closed, down to Restricted occurred in Old Saybrook at the mouth of the Connecticut River. Then again in 2017, a formal public notice and downgrade of growing areas in Westbrook, Old Saybrook, and Old Lyme resulted in reclassifying 39,602 acres from ‘Restricted-Relay’ to the “Prohibited classification”.  In New York, the 2015 changes in classification were water quality related and there were two emergency closures related to excessive rainfalls in August and September. It is standard procedure to close these areas when there is over 3 inches of rainfall. In 2018 there was a small expansion to an existing closure due to poor water quality.

The Connecticut Department of Agriculture Bureau of Aquaculture has been working over the past several years to re-evaluate shellfish growing area classifications in the State in order to accurately reflect the current designated use of the area and effectively utilize the limited resources of the State, while remaining in compliance with the requirements of the National Shellfish Sanitation Program (NSSP).  The shellfish growing areas in the waters of Westbrook, Old Saybrook and Old Lyme are no longer assessed by the Bureau, and as a result must be re-classified immediately to “Prohibited”.   All growing areas in Old Saybrook had been placed in the closed status by the Bureau effective 01/02/2009.  The 2017 re-classification formally changes the legal descriptions for all waters in these towns to Prohibited.

Shellfish areas can be temporarily closed as a result of naturally occurring pathogen outbreaks and harmful algal blooms. Closures due to shellfish-related food borne illnesses caused by the naturally occurring (not sewage or pollution related) marine bacterium Vibrio parahaemolyticus resulted in the extended closure of Connecticut’s most productive oyster grounds in Norwalk and Westport in both 2012 and 2013. New York’s most productive shellfishing area, Oyster Bay Harbor, was closed for several weeks in 2012. In New York, Oyster Bay Harbor and Cold Spring Harbor were closed for several weeks in 2013 after several confirmed Vibrio parahaemolyticus illnesses were traced to those harvest areas. Widespread illness due to a virulent strain of this bacteria plagued the East Coast during the summer of 2013, with other states including Massachusetts, New Jersey and Virginia also closing shellfishing areas after experiencing illness outbreaks caused by Vibrio parahaemolyticus. Since the closings in 2013 the NYS DEC implemented a Vibrio parahaemolyticus control plan.  No recent outbreaks have occurred.



Not all shellfish area classification changes are due to water quality issues impacting shellfish growing areas. Some shellfish closures are administrative in nature, due to excessive rainfalls or the inability to sample a specific location. For example, the areas around marinas that have more than 10 boats are closed administratively in New York.

How is This Target Measured?

The New York State Department of Environmental Conservation (NYSDEC) and the Connecticut Department of Agriculture (CTDOAG) Aquaculture Division regularly monitors shellfish areas for improvements or degradation of water quality and status of pollution sources, and to determine whether its classification for harvesting species should be upgraded or downgraded.


Shellfish beds are regularly monitored to assure that shellfish harvested in commercially and recreationally approved areas are safe to eat.

A variety of shellfish are commercially and recreationally harvested each year from Long Island Sound for human consumption. However, since shellfish are filter feeders, they can become contaminated if they live in polluted water. In order to protect humans from shellfish-borne illness, certain areas in Long Island Sound that have poor water quality are closed to shellfishing. Shellfish beds are regularly monitored by state regulatory agencies to assure that shellfish harvested in commercial and recreationally approved areas are safe to eat. With ongoing efforts to improve water quality, this target will track the progress of increasing the acres in the Sound approved for shellfishing.


Casey Personius, NYS Department of Environmental Conservation

Mark Parker, CT Department of Energy and Environmental Protection

Kristin DeRosia-Banick, CT Department of Agriculture Bureau of Aquaculture

Source of Data



Data Notes

The technical explanation on how the target was selected is found in Appendix B of the Comprehensive Conservation and Management Plan.

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