The Peconic bay scallop, Argopecten irradians irradians, was once an iconic species on Long Island of high economic importance. Between 1985 and 1995, these populations were decimated in response to multiple stressors driven by an increase in eutrophic conditions within the Estuary, which is located on eastern Long Island, where habitats such as this one support several economically important shellfish and finfish fisheries being targeted by recreational and commercial fishermen.
The two most notable drivers of the bay scallop population decline were the loss of eelgrass (Zostera marina) habitats and outbreaks of harmful algal blooms of Aureococcus anophagefferens, also known as Brown tides (Fonseca and Uhrin, 2009; Carrol et al., 2010 and Wall et al., 2013).
Intensive restoration efforts commenced after the population collapse to rebuild the natural populations of Peconic bay scallop, by restocking with hatchery-reared juveniles that would ultimately serve as broodstock when they matured. These restoration measures have been attributed to the resurgence of the Peconic bay scallop fishery, accompanied by a steady increase in commercial landings (Tettelbach et al., 2013 and 2015).
The situation changed in 2019 after reports of adult bay scallop die-offs were recorded in Peconic Bay through field monitoring and fishermen observations. The extent of the die-off was described as “near unprecedented”, where the mortality rate was estimated between 90-99 percent in certain areas in the Peconic Bay, resulting in a total economic loss to commercial fishermen (Tettelbach et al., 2023).
The Peconic Estuary Partnership (PEP) convened a group of scientists, managers, and other experts to assess the possible factors that may have likely contributed to the 2019 die-off. Bay scallops were actively reproducing under less than desirable environmental conditions around the time of the die-off. Water temperatures were abnormally high, approaching bay scallop’s thermal limit, and localized hypoxia was present (Tomasetti et al., 2022). There was an influx of cownose rays that are known to be voracious predators of bay scallop, and this feeding frenzy was supported by the presence of large quantities of discarded shells on the bottom. Given the available evidence, this preliminary dialogue suggested that bay scallops could have succumbed to thermal stress, and it wasn’t possible to determine if cownose rays contributed to the die-off.
This perspective changed drastically when a frighteningly similar die-off occurred in 2020, making it the second event in two years. As a rapid response action, NYS funds dedicated to PEP were redirected to support pathology analyses at the SUNY Marine Animal Disease Laboratory (MADL). The results detected a parasite, Bay Scallop Marosporida (BSM), that is believed to proliferate under prolonged elevated water temperature. While the parasite doesn’t pose any human health concerns, the presence of the organism in high density under stressful conditions (such as elevated water temperature) is sufficient to kill bay scallops (Pales-Espinosa et al., 2023). PEP managers and industry leaders have also raised their concerns about bay scallop recruitment failure in the future, and economic prosperity of commercial fishermen who depend on this fishery. These concerns were acknowledged with the 2021 fishery disaster declaration, allowing fishery managers to implement new remediatory actions. The NOAA appropriation was used to support research to study the parasite and identify bay scallop strains that can tolerate the parasite under high temperature conditions. Funds were also used to enhance monitoring and other data collection efforts and expand aquaculture hatchery efforts.
A multi-year response effort is envisioned to address the bay scallop fishery disaster, prompting PEP to appoint the Peconic Bay Scallop Technical Review Committee (TRC) to allow scientists, managers, and decision makers to jointly monitor and strategize the response coordination being administered in the Peconic Bay and its watershed. The TRC meets twice each year (Spring/Fall) to review the research progress and prepare the annual research/monitoring workplan. The current scope of the fishery disaster coordination incorporates:
• Ongoing monitoring through annual surveys being conducted by Cornell Cooperative Extension of Suffolk County (CCE) over two decades.
• MADL research on bay scallop genomics to identify resilient strains and predation studies.
• CCE bay scallop aquaculture effort to supply seeds being used in the department’s restocking program.
The major findings of this preliminary response effort eliminated cownose rays and harmful algal bloom as potential causes for the fishery collapse. More importantly, the evidence that were collected refined the list of possible reasons for the die-off to the following driving forces:
• BSM infection
• Sustained elevated temperature in the estuary and associated low dissolved oxygen
These preliminary findings allowed policy makers to make informed decisions regarding funding to support future bay scallop research. In summary, the TRC presently serves as a gathering to exchange information among parties involved with the daily fishery disaster response actions, with limited public engagement. Communication is lacking under the existing fishery disaster response framework, and it creates an atmosphere of mistrust among different stakeholders, where facts are sometimes miscommunicated and misleading. The TRC needs to improve the strategies to communicate the accomplishments and findings to other third parties (industry, public, etc.). Communication with stakeholders under this multi-year fishery disaster response must be more structured, and this goal can be achieved with the introduction of a formal open symposium series.