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 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 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 was >$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. Similar mortality events have happened each year through 2024. These mass die-offs have consistently occurred after the first annual scallop spawn in late spring/early summer, allowing populations to sustain themselves. However, with most adult scallops dying in July and August, historically important fall spawns are not occurring (which help buffer population fluctuations). Furthermore, and of greatest importance to baymen, fish markets and Peconic bay scallop devotees, few adults survive to the start of the harvest season in early November.
• In collaboration with scientists form Stony Brook University, we continue to investigate the causes of these die-offs. Our work has shown that these mass scallop mortalities result from a combination of factors - a newly discovered bay scallop parasite, in conjunction with high water temperatures, and, perhaps to a lesser extent, low dissolved oxygen levels and the physiological stress of spawning. The disease is not harmful to humans, but appears to be the main driver of the scallop die-offs.

Last updated December 30, 2024