Tettelbach bay scallop (1)
Image by Stephen Tettelbach

Adult Peconic bay scallop

Tettelbach bay scallop (2)
Image by Stephen Tettelbach

Spawning bay scallops-NW Hbr (from Tettelbach & Weinstock 2008: Bulletin of Marine Science

Tettelbach bay scallop (3)
Image by Stephen Tettelbach

Kevin Cahill tending scallops in lantern nets, Orient Harbor longline system

Tettelbach bay scallop (4)

Christian Tettelbach conducting scallop population surveys

tettelbach bay scallop longline system star primary site
Image by Stephen Tettelbach

Orient Harbor, NY. Large star is the site of our primary spawner sanctuary longline system

Tettelbach bay scallop (6)
Image by Stephen Tettelbach

Transect survey of bay scallop and predator populations - Hay Beach, Shelter Island, NY

Tettelbach bay scallop (7)
Image by Stephen Tettelbach

Peconic bay scallop densities have increased dramatically since we began in 2006

Scallop Program: Overview and Results

  • Prior to the mid-1980's, Peconic bay scallops supported a commercial fishery with a dockside valued of up to $2 million per year. Including economic multipliers, the fishery annually contributed more than $10 million to the local economy. For 400-600 full-time baymen, bay scallops were their primary source of income.
  • Beginning in 1985, a series of brown tide algal blooms decimated Peconic bay scallop populations and pushed them to the brink of extinction. With the disappearance of the scallop fishery, most baymen had to leave the water and find other jobs, retire, or move out of state.
  • Bay scallop restoration efforts were started in 1986 by local baymen; Cornell Cooperative Extension and Long Island University have been leading these restoration efforts now for over 30 years.
  • Our restoration work in the late 1980's and early 1990's helped rebuild the Peconic scallop populations and fishery, but a severe brown tide in 1995 again wiped them out.
  • After 1995, scallop populations remained at very low levels and fishery harvests averaged less than 1% of historical levels - even though no brown tide blooms have occurred in the Peconic Bays since then.
  • Beginning in 2005, Cornell Cooperative Extension and Long Island University began the largest bay scallop restoration effort ever attempted in the United States. With funding from the Water Quality Protection and Restoration Program of Suffolk County, >8 million scallops have been raised in Cornell's hatchery in Southold and planted into the Peconic Bays.
  • These restoration efforts have contributed to a huge increase in scallop populations. LIU and Cornell scientists have documented an increase in scallop larval settlement of >3200% in Orient Harbor, the site where the primary spawner sanctuary is in place. Populations of juveniles and adult scallops in Orient Harbor and other Peconic embayments increased by >1000% through 2018.
  • Commercial fishery landings from 2010 through 2016 have averaged >1300% higher than those recorded in the 12 years prior to the start of our restoration program, and >3100% higher in 2017 and 2018. The cumulative economic benefit of these increased scallop harvests has been >$8 million to baymen and >$60 million to the regional economy.
  • In 2019, a mass die-off of adult bay scallops occurred throughout the Peconic Bays, with declines in population sizes and commercial fishery landings of ~95%. In 2020, another mass die-off occurred, with >98% mortality of adult scallops occurring between May/June and October. These mortality events do not seem to have affected juvenile scallops to a large degree.
  • In collaboration with scientists form Stony Brook University, we continue to investigate the causes of these die-offs. At this point, we believe they have resulted from a combination of factors - including high water temperatures, low dissolved oxygen levels and a newly discovered bay scallop parasite, in conjunction with the physiological stress of spawning. Large numbers of cownose rays, a primarily southern species that is known to prey on adult shellfish, have been seen in Long Island waters (including the Peconic Bays) in 2019 and 2020; we are working to understand if these have contributed to the scallop die-offs.


Christopher F. Smith
Senior Educator • Natural Resources

Last updated February 11, 2021