Ecosystem Targets and Supporting Indicators
Show/Hide Table Data
While current New York data was available for the entire time series, Connecticut harvest data was not reported from 2010-2015. Harvesters re-established reporting their harvest (landing) data to the Connecticut Department of Agriculture, Bureau of Aquaculture’s Shellfish Sanitation Program in 2016. Oyster landings have remained relatively stable, while hard clam landings have been declining.
There is a rich history of shellfishing in Long Island Sound and the status varies by state and species.
Connecticut
Oysters and hard clams are commercially harvested in Connecticut and remain important commodities. Historically, oysters have been the most important molluscan shellfish fishery in the state. Between 2020-2024, a total of over 130 million oysters and 100 million hard clams were harvested.
Oystering has occurred in Connecticut for centuries. There was a significant increase in oyster landings in the early 1990’s following an extensive restoration project on the Bridgeport-Stratford Natural Oyster Seed Bed, where seed oysters naturally recruit. However, Connecticut oyster populations were negatively impacted when an oyster disease, MSX, infected and resulted in statewide mortality events in adult and seed oyster populations in 1997 and 1998, respectively (Oyster Clam Diseases). Oyster populations began to recover by 2006. While hard clamming started in the 1950’s on a small scale, the industry did not begin to expand until the 1990’s. During the decline in oyster landings and the lobster die-off in 1998-1999, the number of vessels hard clamming in the State increased. As a result, hard clam landings increased and peaked around 2008. Additional information about the decline of hard clam landings can be found on the Bureau of Aquaculture website (Shellfish Industry Profile). Following the population recovery, oyster landings have remained relatively stable, except for the brief economic impact of the COVID-19 pandemic in 2020-2021.
New York
Historically, the oyster industry represented one of the most commercially important shellfish resources in New York State dating back to the 1800s. Oyster production peaked in 1911, after which the oyster industry observed a steady decline in production due mainly to a lack of adequate supply of seed oysters, irregular sets in Connecticut and pollution from urbanization that led to the closure of shellfish lands in Raritan Bay, Jamaica Bay, and areas around New York Harbor. For the most part, the industry has shifted away from wild harvest and is depending more on cultured oysters.
The hard clam industry began in the 1930s resulting from the declining abundance of oysters and the loss of oyster grounds. By 2001, hard clam landings dropped to a low of 1.8 million pounds of meat valued at $13.5 million. The decline in the population of hard clams can be attributed to over-harvesting, recruitment failure, changes in water quality, poaching of seed clams, loss of suitable habitat and pollution (Timmons 2004), as well as harmful algal blooms (HABs). Hard clams have been extensively cultured throughout the East Coast to bring populations back to fill the void left by declining fisheries. Improvements have been observed since 2001 however, harvests are on the decline again.
Historically, the bay scallop represented a commercially important shellfish resource in New York State, particularly in Peconic and Gardiner’s Bays on the eastern end of Long Island. However, in the 1930s bay scallop populations and catch crashed alongside eelgrass die-offs in North America and Europe related to “wasting disease”, a disease that slowly decays the leaves of the eelgrass, an important habitat for juvenile bay scallops (Fonseca and Uhrin 2009). Some populations were able to slightly recover over time, but in the 1980s additional eelgrass die-offs occurred in the coastal waters of Long Island due to an unusual bloom of the alga, Aureococcus anaphagefferens, also known as brown tide. This algae bloom devastated bay scallop populations in the Peconic Bay system. The sequential events of eelgrass die offs and brown tide events caused bay scallops in Long Island’s waters to come close to extirpation. While there are efforts to revitalize bay scallop populations since 2006, recruitment and landings have fluctuated and are still significantly impacted by die-offs and diseases.
There are barriers for entering the aquaculture industry. It is expensive for a new aquaculturist to establish a company and start an operation, learn and meet the National Shellfish Sanitation Program standards, and they will not begin to see a profit for multiple years. The Department of Agriculture has worked to support the development of new, small companies through Public Act 23-184 (Opportunities for New Aquaculture Businesses) and the Branford Aquaculture Initiative (Branford Aquaculture Initiative). In addition, Connecticut Sea Grant annually offers a Foundations of Shellfish Farming course (Foundations of Shellfish Farming Training Course | Connecticut Aquaculture and Fisheries), which the Department requires all prospective growers to complete.
As with farming on land, aquaculture is susceptible to product loss through predation and disease, as well as environmental damage from storms and winter kill.
There has been significant industry consolidation in Connecticut, particularly in the last 10 years. With an aging industry, the sector needs to attract and retain new individuals.
Because shellfish are typically consumed raw and can be contaminated by point and non-point pollution sources, the industry is highly regulated to protect public health. In years with frequent and severe storm events, there are a lot of shellfish bed closures. These are temporary periods when the industry cannot harvest from particular areas, or in extreme conditions, the entire state. When water quality and shellfish tissue results return to acceptable levels, the Department of Agriculture reopens shellfish beds to harvesting. The industry is also significantly impacted by wastewater treatment plant and sewer collection system discharges. Continuing to invest in wastewater infrastructure, particularly as populations increase and infrastructure ages, is critical to maintaining a viable shellfish industry.
The New York State Department of Environmental Conservation (NYSDEC) and the Connecticut Bureau of Aquaculture track the weight (by bags or bushel) and economic value of oysters, clams, and scallops commercially harvested each year.
The filter-feeding capacity of shellfish can help keep near-shore waters clean by controlling phytoplankton abundance in the water column.
The annual harvest numbers for oysters, clams, and scallops are an indicator of both abundances as well as the socioeconomic importance of these species to Long Island Sound. Since harvest is only allowed in approved waters, this target is also an indirect reflection of water quality in the near-shore environment. This is particularly true in Connecticut where shellfishers can only harvest on their own leased beds.
Shellfish naturally remove nitrogen from the environment. Shellfish aquaculture in Greenwich Bay, Connecticut removes nitrogen at an estimated value of $2.3-5.8 million/year (2020, Dvarskas et al).
Samarra Scantlebury, NYSDECsamarra.scantlebury@dec.ny.gov
Alissa Dragan, Connecticut Department of Agriculture Bureau of Aquaculture
alissa.dragan@ct.gov
NYSDEC and CT Bureau of Aquaculture
Learn more about shellfish aquaculture on NOAA Fisheries. Photo courtesy of Carol DiPaolo.
Subscribe to receive our e-newsletter, Sound Matters by providing your email address. Interested in a free copy of our print newsletter, Sound Update? Then also provide your home/company/school address.
"*" indicates required fields