The Atlantic sea scallop (Placopecten magellanicus) fishery on the Northeast U.S. continental shelf generates approximately USD 500 million ex-vessel revenues annually, making it one of the most valuable single species fisheries in the United States. Wind energy development is planned for key areas on the U.S. Mid-Atlantic shelf where the Atlantic sea scallop fishery operates, creating novel challenges in managing trade-offs between traditional users like fisheries and new users like offshore wind energy. An agent-based modeling framework that integrates spatial dynamics in Atlantic sea scallop stock biology, fishing fleet behavior, and federal management decisions, was implemented to investigate how offshore wind energy infrastructure may directly affect the Atlantic sea scallop fishery. The effect of current and planned wind energy lease areas on Atlantic sea scallop was evaluated with simulations that restricted Atlantic sea scallop fishing in lease areas, transiting lease areas by the fishing fleet, or both. The relative effects of these restrictions were measured against a simulation without any restrictions. Simulations indicated that wind energy lease areas have minor impacts on the present-day fishery, with changes in days fished, landings per unit effort, and total fishing trips under 5% with impacts varying across development scenarios and fishing ports. These results suggest offshore wind development may have limited impacts on fishing. However, these changes can be magnified by the value of the Atlantic sea scallop fishery, resulting in substantial economic impacts. Imposed restrictions on fishing location and transiting lease areas resulted in spatial shifts in fishing trips, with larger changes associated with the larger proposed wind lease area footprints, particularly in the southern part of the Atlantic sea scallop range. The largest negative effect of wind restrictions was the reduction in Atlantic sea scallop biomass outside of the lease areas (similar to 4-9%), likely due to effort displacement, even though the total stock biomass remained relatively unchanged. The simulation results highlight the need for a holistic approach to assessing the complex interactions between offshore wind energy lease areas, Atlantic sea scallop stock dynamics, and fishing vessel transit routes to accurately identify and address potential impacts. This information is critical for fishers and managers to assess mitigation approaches and serves as a valuable tool for future planning amid interactions between commercial fisheries, the offshore wind energy industry, and changing environmental conditions.

Objective A major challenge in managing wild-capture fisheries is their dependence on natural recruitment, which can be highly variable. The Atlantic sea scallop Placopecten magellanicus supports one of the most valuable fisheries in the United States, with annual exvessel values of US$360-600 million since 2010. Fishery managers utilize annual surveys to document recruitment events and rotational area management to protect juveniles from fishing pressure. Although these measures are effective, recent high-density recruitment events have prompted consideration of a broader set of management options. We propose developing decision trees to aid in the management of future high-density recruitment events.Methods To guide decision tree development, we asked resource managers, industry advisors, and researchers to rank their concerns associated with managing high-density recruitment events, evaluate the feasibility of proposed management measures, and rank the importance of management information in their decision-making process.Results Participants expressed high levels of trust in the results of annual population surveys used to delineate the abundance and distribution of the resource, but they were concerned about elevated fishing mortality due to poor fishing practices in high-density areas. Participant perceptions of the proposed management measures informed the development of two decision trees: (1) evaluating management options for new recruitment events and (2) evaluating management options for rotational areas that are currently closed.Conclusions The decision trees that we developed provide a structured framework to evaluate management considerations, with the aim of streamlining the management process for future high-density recruitment events in the Atlantic sea scallop fishery. Wild fisheries depend on natural recruitment, which can be highly variable. We developed two decision trees for managing high-density recruitment events in the Atlantic sea scallop fishery. These decision trees provide a structured method for evaluating diverse management options.

For the Atlantic sea scallop, Placopecten magellanicus, rotational access area management has gained support as an effective management tool to conserve and enhance the scallop resource. Multiple optical and towed gear surveys are conducted annually to provide information on the abundance and distribution of adult and juvenile scallops, enabling managers to respond to changes in biomass in different subunits. Recently, a significant divergence in area-specific biomass estimates was observed between different survey methods, with optical survey estimates exceeding those from towed dredge surveys. The leading theory for these differences is that the survey dredge would be saturated during the standard 15-minute tows in high-density areas, leading to underestimates of stock biomass. This study developed a methodology to directly observe and count scallops in the dredge path during survey operations. Seventy-three tows were conducted off Southern New England in the Nantucket Lightship Area and the Great South Channel, including in known high-density scallop beds. Estimates of catch efficiency were calculated by comparing the number of scallops in the dredge path to those caught in the dredge. The catch efficiency of the survey dredge was significantly reduced when sampling in high-density scallop beds, declining from 0.42 at low-density to 0.09 in the high-density beds. High catch volumes of scallops in the dredge were observed to cause the sweep chains to lose contact with the seafloor, resulting in loss of scallops under the dredge. Ultimately, a better understanding of the survey dredge performance and catch efficiency in different density areas will help reduce uncertainties in biomass estimates.

The U.S. East Coast sea scallop (Placopecten magellanicus) dredge fishery has exceeded the subannual catch limits for either the northern windowpane flounder (Scophthalmus aquosus) or the Georges Bank yellowtail flounder (Pleu-ronectes ferruginea) stock because subannual catch limits were mandated. Subannual catch limits have been in place since 2011 for yellowtail flounder and 2017 for windowpane flounder. In an effort to mitigate flatfish bycatch in the fishery, paired sea trials were conducted in 2023 to test an experimental 15.24-cm square mesh escape panel installed in the standard twine top of a sea scallop dredge. The control dredge was a Turtle Deflector dredge with either a seven-row apron or a mandated modified dredge frame with a five-row apron. Three experimental dredge treatments were tested: (1) a two-row escape panel (paired tows N = 101), (2) a three-row escape panel (paired tows N = 118), and (3) a two-row escape panel with the five-row apron dredge (paired tows N = 117). Differences in the mean catch of sea scallops, windowpane flounder, and yellowtail flounder were compared between control and experimental dredges with a repeated measures ANOVA. No significant difference in the mean catch for either flatfish was detected between gears. P values for windowpane flounder mean catch were 0.16 for Treatment 1, 0.87 for Treatment 2, and 0.42 for Treatment 3. For Treatment 3, the P value for yellowtail flounder catch was 0.40. Sea scallop catch in the experimental gear was greater in Treatment 1 (P value = 0.07) and Treatment 3 (P value < 0.01). Catch was significantly less for Treatment 2 (P value < 0.01). Catch comparison models examined the relative catch-at-length between dredge configurations. Modeling results indicated a significant effect of the experimental gear treatment on scallop catch-at-length. All experimental treatments caught fewer small scallops greater than 90 mm while retaining more large scallops. For flatfish, there was no significant effect of the experimental gear treatment on catch. The preferred model for windowpane flounder indicated reduced catch-at-length across the length range observed. Few yellowtail flounder were encountered during the project.

The Atlantic sea scallop Placopecten magellanicus supports one of the most valuable federal fisheries in the USA, with annual ex-vessel values of US$400-600 million since 2010. Among other strategies, the fishery utilizes rotational area management to protect juvenile sea scallops, increasing yield per recruit and spawning potential. While generally successful, area management was challenged by 2 extremely high-density recruitment events. Juveniles at both study sites, the Nantucket Lightship Closed Area and the Elephant Trunk portion of the Mid-Atlantic Access Area, persisted at high densities (up to 39 and 5 sea scallops m-2, respectively) and initially exhibited poor growth, yield, and gamete production. The effect of sea scallop population density on reproduction was investigated through quarterly sampling from May 2018 through January 2020 in low-, medium-, and high-density strata. Reproductive effort, i.e. the proportion of energy devoted to gamete production, was quantified to investigate differences in energy allocation across density, depth, shell height, reproductive stage, and sex. Reproductive activity was limited in the Nantucket Lightship high-density stratum, where the percentage of sea scallops staged as mature or spawning reached 50% during only 1 of 7 sampling trips, compared to 4-6 sampling trips in other strata. Population density was a significant predictor of reproductive effort, with a 28% reduction in reproductive effort from the highest densities to more typical densities. These results illustrate the complexities of managing fisheries for heterogeneous populations of sessile benthic invertebrates. Negative density-dependent effects should be monitored and accounted for in future extreme recruitment events.

Radio Frequency Identification (RFID) represents a technology that has the potential to enhance many aspects of the Atlantic sea scallop fishery. Driven by fishery management and market forces, fishery product traceability benefits fisheries managers, consumers, and fishermen. In order to demonstrate the capabilities of RFID technology in the scallop fishery, a solution is proposed that would help establish clear Chain of Custody (CoC) so that the scallop supply chain can be better documented. Implementation and acceptance of any new technology will hinge on effective communication and extension efforts that can leverage the multi-benefit aspects of adopting RFID into the fishery.

In the last decade, there has been increasing interest in the use of artificial illumination as a bycatch reduction device. In the U.S. West Coast groundfish bottom trawl fishery, research has found that the addition of green light-emitting diode (LED) lights to the upper bridles of low-rise cutback trawls significantly reduced Pacific halibut (Hippoglossus stenolepis) bycatch. Recent regulation changes in this fishery now permit high-rise trawls, a gear configuration with a higher vertical opening, in areas where only low-rise trawls were previously permitted. This study conducted catch comparison and catch ratio analyses to determine if catches of Pacific halibut and three commercially important groundfishes (e.g., petrale sole [Eopsetta jordani], Dover sole [Microstomus pacificus], and sablefish [Anoplopoma fimbria]) differ between illuminated and non-illuminated tows for a high-rise bottom trawl. Illuminated tows caught fewer individuals than the non-illuminated tows across all species, including Pacific halibut; however, the difference in catch efficiency was not significant. Total catch volume did have a significant positive effect on levels of glucose and lactate for Pacific halibut. However, no statistically significant differences between illuminated and non-illuminated tows were exhibited across all of the physiological parameters assessed. The results from our study provide valuable information to fishers and managers that can be used for future decision-making and identifying research priorities.

The catch efficiency of towed fishing gears is the fraction of the target species in the gear path that were caught and retained. Catch efficiency is fundamental for calculating population status required for establishing fisheries management reference points. Consequently, catch efficiency has been estimated for many commercially important scallop (Pectinid) fisheries. This article synthesizes and discusses estimates of catch efficiency of towed gears used to target scallops, the methods for estimating catch efficiency and the factors that influence these estimates. There exists considerable variation in catch efficiency estimates among studies (0.1 to 0.7), and it is important that this variation is accounted for during surveys and stock assessments to avoid erroneous advice and estimates. The high variation was driven by differences in experimental conditions, estimation methods and scallop behavior. Scallop size and substrate type were the two most common reporting categories discussed in the studies and consequently should be considered the two most important drivers of catch efficiency. Other important factors such as gear specifications, and scallop species were featured in some studies. This review will be highly useful for designing catch efficiency experiments, survey design and stock assessments by understanding, and accounting for, catch efficiency variation.

The Anaskid nematode, Sulcascaris sulcata has a worldwide distribution and utilizes benthic molluscs as an intermediate host with sea turtles (Chelonioidea) serving as definitive hosts. During the spring of 2015, sea scallops (Placopecten magellanicus) harvested along the mid-Atlantic Bight (MAB) presented with rust-colored lesions on the surface of the adductor muscles. Morphological and molecular investigations determined that the lesions were caused by an infection by third- and fourth-stage larval S. sulcata. Seasonal monitoring from 2015 to 2018 delineated a stable spatial distribution of infected scallops that corresponded to a large 2013 year-class of scallops and persistent utilization of this habitat by seasonally resident loggerhead turtles. Given the life cycle and etiology of S. sulcata, the risk to human health via direct infection or allergic reaction appears to be low, however, the spatiotemporal scale of nematode-infected scallops resulted in fishery-level impacts with respect to the spatial distribution of fishing effort in response to product quality and depreciation of the value of landed scallops. The long-term trajectory of the epizootic remains unclear and continued monitoring of the spatiotemporal distribution of nematode-infected scallops is warranted as S. sulcata spatial distribution is likely dependent upon sea scallop abundance, which is currently trending toward more northerly portions of the MAB.

Generalized linear models (GLM) and generalized additive mixed models (GAMM) were developed to examine for differences in fishing power, also referred to as a vessel effect, for three commercial fishing vessels chartered by the Virginia Institute of Marine Science (VIMS). The vessels conducted a fishery-independent sea scallop dredge survey of the MidAtlantic sea scallop resource in 2015. Surveys have continued since 2015 using a multivessel approach, and understanding the implications of a potential vessel effect on scallop catch is important for management and assessment of the resource. Surveys are conducted yearly to support annual fishery specifications and contribute biological and catch data for stock assessments. Generalized linear models tested for an effect of vessel on the total number of scallops captured and indicated survey strata and rotational area were significant predictors. Generalized additive mixed models tested for a vessel effect on scallop catch-at-length with length, vessel, strata, rotational area, and an interaction of vessel and length as fixed effects and survey station as a random effect. Two preferred GAMM were identified for the catch-at-length analysis. One model indicated that strata and rotational area had significant effects on scallop catch-at-length, whereas the interaction term was not significant. The second model did not include the interaction term or vessel as a predictor. Results presented here are consistent with previous calibration studies conducted for scallop dredge surveys suggesting that scallop catch is robust to the effect of vessel and support the use of a suite of industry vessels in the VIMS sea scallop surveys.

Discard mortality can represent a potentially significant source of uncertainty for both stock assessments and fishery management measures. While the family Pectinidae is considered to be robust to the capture and handling process, understanding species-specific discard mortality rates is critical to characterize both population dynamics and to develop regulatory measures to meet management objectives. The discard mortality rate for the U.S. dredge fishery of sea scallop Placopecten magellanicus was estimated empirically via a retention study aboard industry vessels under commercial conditions. Over 16,000 sea scallops were assessed via a composite index of scallop vitality that consisted of semiqualitative measures of both overt trauma (shell damage) and response to stimuli. Results indicate that overall sea scallop discard mortality was 21% and consistent with the values currently assumed in the stock assessment. Survival mixture models support the utility of a simple metric of physical trauma as an effective predictor of mortality. Exposure time was also identified as a positively correlated factor that was important in describing the discard mortality process. Application of experimental results highlight the need to consider some operational characteristics of the fishery to reduce potential discard mortality.

The Atlantic sea scallop Placopecten magellanicus dredge fishery is one of the most lucrative commercial fishing industries in the northeastern United States, and fish bycatch can comprise up to similar to 42% of the total catch. Benthic species, such as flatfish, are particularly susceptible to unintended capture in scallop dredge gear, and mitigating bycatch and associated mortality has been mandated a priority for fisheries management. Based on this management need, the present study evaluated the physical, physiological, and behavioral stress responses of Yellowtail Flounder Limanda ferruginea, Windowpane Scophthalmus aquosus, and Fourspot Flounder Paralichthys oblongus to capture in the scallop dredge fishery. More specifically, we used generalized additive models and linear regression models to assess the influence of various fishing practices, environmental conditions, and biological factors on injury condition, physiological parameters, and reflex indicators. Although these flatfish species appeared to be physically resilient to capture based on an observable injury assessment, dredge capture and handling factors proved stressful, with the degree of immediate mortality, physiological disturbances, and reflex impairment varying by species. While multiple factors influenced the degree of stress in these species, based on our results the reduction of tow duration and limiting air exposure/sorting duration would likely be the most effective strategies to mitigate the impact of scallop dredge fishing on these flatfish species.

Discard mortality studies are considered a primary research priority, particularly for species and fisheries where discard rates are high. Monkfish (the commercial name for Goosefish) Lophius americanus supports the most lucrative finfish fishery in New England, and it is also the second highest bycatch species by weight in the sea scallop dredge fishery. Despite its commercial importance, no data exist with respect to monkfish discard mortality estimates for any gear type. The goals of this study were to evaluate the discard mortality process for monkfish captured in sea scallop dredge gear, estimate mortality rate, and develop best handling/management practices to mitigate the impact of monkfish bycatch in the sea scallop dredge fishery. Discard mortality was estimated during a field study conducted between June and October 2017 on board sea scallop commercial fishing vessels on Georges Bank in the Northwest Atlantic. Pop-up satellite tags were affixed to 60 monkfish to track survival from 14 to 28 d postcapture. From these monitored individuals, high predation rates were observed (n = 18 out of 26 mortalities), and the bulk of mortalities (n = 21) occurred within the first 24 h of discarding. However, in light of having no clear method for disentangling capture-related and tag-induced predation, predation was noted exclusively as one or the other to account for uncertainty and provide an upper and lower bound of mortality. This approach suggested that the discard mortality rate was between 17.9% and 54.1% for monkfish discarded by scallop dredges and that elevated air temperatures (above thermal preferences) may contribute to increased mortality. Based on these results, it appears that monkfish discard mortality is lower than previous assumptions of 100%, and potential best-practice management suggestions moving forward may include minimizing fishing in areas of high monkfish abundance or scheduling rotating time/area closures during periods when air temperature exceeds monkfish thermal tolerance of 13 degrees C.

We examined evidence for larval spillover (increased recruitment outside the closures) of Atlantic sea scallops (Placopecten magellanicus) due to rotational closures in the Mid-Atlantic Bight using a 40-year fisheries survey time series and a larval transport model. Since the first closure of the Hudson Canyon South (HCS) area in 1998, mean recruitment in the two areas directly down-current from this closure, Elephant Trunk (ET) and Delmarva (DMV), increased significantly by factors of about 7 and 2, respectively. Stock–recruit plots indicate that low biomasses in HCS were associated with reduced mean recruitment in ET and DMV. Simulations indicate that larvae spawned in HCS often settle in the two downstream areas and that model-estimated settlement (based on gonad biomass in HCS and year-specific larval transport between the areas) is correlated with observed recruitment. This study gives strong evidence that the rotational closure of HCS has induced increased recruitment in down-current areas.