The area of the Sound approved for harvesting shellfish was less in 2020.
The Connecticut Department of Agriculture's (DoAg) Bureau of Aquaculture and Laboratory Services monitors water quality and classifies shellfish growing areas according to their potential for yielding healthful, uncontaminated shellfish. The chart* shows preliminary data for 2020 for the acreage of shellfish growing areas that are designated as restricted areas that include “prohibited”, “restricted relay”, and “conditionally restricted relay” designations. There has been a slight decline in “approved” acreage in 2020 due to a downgrade of approved acres in Westport offshore of the Saugatuck River due to bacterial exceedances at lower rainfall amounts. The area of restricted/prohibited shellfish growing areas is determined by bacteria contamination, which is an indicator of possible sewage contamination. Changes in the classification of shellfish growing area are related to improvement or decline in water quality based upon the results of water quality monitoring and/or updated sanitary survey findings.41
Water quality assessment criteria for shellfishing as a designated use only applies to inner-shore, and mid-shore estuarine waters where shellfish growth is viable, which is approximately 50 percent of Connecticut’s estuarine waters. According to the Department of Energy and Environmental Protection’s (DEEP) 2020 Integrated Water Quality Report, only about 16 percent of the estuarine waters assessed can fully support shellfish harvesting from Class SA waters.** This percentage is unchanged since the 2018 report. Meanwhile, the percent of estuarine waters that can fully support shellfish harvesting from Class SB waters declined since the 2018 report.
Goal: The goal for marine shellfishing, adopted in the 2015 edition of the Long Island Sound Study's Comprehensive Conservation and Management Plan, is to “upgrade 5 percent of the acreage restricted or closed for shellfishing in 2014 by 2035”. The “restricted or closed” acreage in 2014 totaled 167,264 acres, which included areas designated by DoAg as “prohibited”, “restricted relay”, and “conditionally restricted relay”. Therefore, the goal is a reduction of restricted or closed acreage to 158,901 acres by 2035, shown on the chart as a horizontal line.
Technical Notes: *The vertical axis in the chart above has been shortened, beginning at 100,000 acres rather than the customary zero. **SA waters allow shellfish harvesting for direct human consumption where authorized, whereas SB waters allow shellfish harvesting with depuration or relay where authorized. Depuration is the action or process of freeing something of impurities. In the case of shellfish, this usually means moving the shellfish to areas with better water quality.
41 DoAg, Bureau of Aquaculture; personal communication with K. DeRosia-Banick, March 12, 2021.