Explore the vast range of titles available.

The eastern oyster once provided major societal and ecosystem benefits, but these benefits have been threatened in recent years by major declines in oyster harvests. In many areas, recovery of oyster aquaculture faces significant societal opposition and spatial constraints limiting its ability to meet expectations regarding future food needs and provision of ecosystem services. In Virginia, oyster aquaculture has begun to rebound, concurrent with an increase in subaqueous leased areas (over 130,000 acres of grounds are currently leased). Though private leases must in theory be used for oyster production, in practice, they can be held for other reasons, such as speculation or intentional exclusion of others. These factors have led to large variation over time and space in the use of leases in the lower Chesapeake Bay, and privately leased grounds are now thought to be underutilized for oyster production. This research examined potential barriers to expansion of oyster aquaculture in Virginia. We first evaluated if a lack of space was limiting industry expansion and quantified temporal and spatial trends in the use and productivity of leases. Then, differences in used and non-used leases were investigated in relation to variables thought to be related to “not in my backyard” attitudes, congestion, speculation, local economic and environmental conditions. Finally, the performance of the Virginia leasing system was compared with those in other states along the U.S. East and Gulf Coasts. We found limited evidence of spatial constraints though strong evidence of social and regulatory inefficiencies. While rates of lease use increased from 2006 to 2016, only 33% of leases were ever used for oyster production and about 63% of leaseholders reported no commercial harvests. Non-used leases tended to be smaller, and were found in more populated, high-income regions, consistent with both speculative and exclusionary uses. Virginia was found to have the lowest levels of total production of cultured oysters per leased acre among the states of the eastern U.S. These results indicate that there is room for oyster aquaculture expansion in Virginia if societal, regulatory and economic barriers can be reduced or if existing leased areas are used more efficiently.

Observed production sets in multispecies fisheries are affected by regulatory incentives influencing spatiotemporal fishing decisions. Rights-based output controls can promote selective fishing; however, this ability may be limited and insufficient in achieving full utilization of catch quotas. We measure fishing selectivity for bottom trawlers catching federally regulated groundfish in the Gulf of Maine and Georges Bank before and after the introduction of rights-based output controls. Directional distance functions are applied to tow-level catch data collected by fishery observers to construct a measure of selectivity equal to the difference between strong and weak output disposal efficient production frontiers. Quantile regressions are then used to estimate the change in median selectivity associated with the introduction of catch share management, controlling for spatial, temporal, and individual factors. A significant improvement in selectivity was found for tows in Georges Bank following the 2010 management change, though production is still largely characterized by imperfect selectivity.

Fishery enhancement methods are being explored globally to sustain commercial and recreational fisheries through improving the productivity and management of marine populations impacted by anthropogenic stressors. It is expected that access to important Atlantic surfclam fishing grounds will be limited or lost due to growing overlap with offshore wind energy development. This study explores the economic viability of large‐scale hatchery production to improve fishery access and potentially offset additional costs, reduced revenues and potential job losses associated with the displacement of the fishing fleet. Reports and primary literature were used to understand the growth and survival of Atlantic surfclams in hatchery and nursery settings to calculate the scale of hatchery efforts needed to support one million (1M) bushels of fishery‐sized clams (>120 mm). Data on labour, energy, construction and material inputs and costs for hatchery and nursery production were gathered by analysing available literature and information provided by hatchery managers, researchers and others knowledgeable about shellfish hatchery production. A techno‐economic cost model and Monte Carlo analyses were employed to explore average costs and their variability. This study suggests that 374M–2.1B Atlantic surfclams are needed at the end of the hatchery stage to produce 1M bushels of market‐sized product. Total production costs range from$3.7 to $ 15.1M, including$2.9–$ 13.3M in hatchery costs and$800K–$ 1.9M in nursery costs. Under current market conditions, where Atlantic surfclams regularly sell for$14–$ 17/bushel, this analysis suggests that hatchery production could be considered a viable fishery enhancement method that supports human access to the fishery, though several additional questions remain. This study explores the economic viability of large‐scale hatchery production to improve fishery access and potentially offset additional costs, reduced revenues, and potential job losses associated with the displacement of the Atlantic surfclam fishing fleet due to anthropogenic stressors. Total production costs range from$3.7M to $ 15.1M, including$2.9M ‐ $ 13.3M in hatchery costs and$800K‐$ 1.9M in nursery costs. Under current market conditions, where Atlantic surfclams regularly sell for$14‐$ 17/bushel, this analysis suggests that hatchery production could be considered a viable fishery enhancement method that supports human access to the fishery, though several additional questions remain.

Noncompliance is a central challenge for conservation, but in settings with limited access to behavioral data, it can be difficult to evaluate what drives compliance. Conservationists can measure and evaluate resource users' attitudes, and in so doing, leverage a complementary, nonbehavioral measure for evaluating compliance. In Greenland, wild Atlantic salmon (Salmo salar) fishers are under increasing regulatory pressure to report salmon catch because the majority of North Atlantic salmon stocks are classified as suffering. The objective of this study is to measure salmon catch reporting compliance, reporting behavior, and attitudes toward Greenland's salmon management. We surveyed Greenland's licensed salmon fishers, used an unmatched count technique to estimate the incidence of underreporting salmon catch, and linked salmon fishers' actual catch reports to their survey responses. In 2019, more than 84% of salmon fishers reported their catch and demonstrating high levels of compliance. We also found that salmon fishers did not indicate strong instrumental motivations for reporting, but exhibited moral obligations and normative, legitimacy‐based motivations to report catch. Salmon fishers found regulations to be fair, and that regulatory authorities were professional and acted honestly. Catch underreporting was also remarkably low, with 90–94% of respondents stating that they report all their catch. Joining together individuals' attitudinal and behavioral responses to conservation rules illustrates the benefits and limitations of expanding actor‐based theories of compliance. This case of already high levels of compliance offers empirical evidence for further improving fisheries compliance, and it also illustrates the limitations that fishery managers face when conserving a highly migratory species. Attitudes and behaviors help explain compliance in Greenland's Atlantic salmon fishery. Joining together individual's attitudinal and behavioral responses to conservation rules illustrates the benefits and limitations of expanding actor‐ and opportunity‐based theories of compliance. This case, where levels of fisheries compliance is high, offers empirical evidence for improving compliance in fisheries and illustrates the limits of fisheries management for conserving a highly migratory species.

In 2009, Rhode Island implemented a pilot catch share program around summer flounder, or fluke, a state-managed species that is jointly harvested with the Northeast Multispecies groundfish complex. A sector was given a fluke allocation to land when they wished, while the rest of the fleet was managed through sub-seasonal total harvest caps and daily trip limits. Sector members avoided fluke landings during seasonal fluke derbies, instead shifting landings to post-derby closures in the general fishery, when the price was higher. However, they also affected prices of species they targeted instead. We combine predictions of counterfactual 2009 daily landings by sector vessels with a panel model of trip-level ex-vessel prices for 25 products targeted by the groundfish fleet to project what revenues would have been in the absence of the sector program. We find the pilot program increased fleetwide revenues by over $800,000, including benefits of over $250,000 to non-sector vessels.

Background Pop-up satellite archival tags (PSATs) are a valuable tool for estimating mortality of pelagic fishes released from commercial and recreational fishing gears. However, the high cost of PSATs limits sample sizes, resulting in low-precision post-release mortality estimates with little management applicability. We evaluate the performance of a lower-cost PSAT designed to enable large-scale post-release mortality studies. The tag uses solar rather than battery power, does not include a depth sensor, and transmits daily summaries of light and temperature data rather than high-resolution habitat profiles, contributing to a substantially lower per-unit price. We assessed the tag’s ability to detect mortality while also estimating the post-release mortality of juvenile (119–< 185 cm) Atlantic bluefin tuna ( Thunnus thynnus ) caught using light-tackle angling methods along the US east coast. Results Using high-resolution data from previously deployed PSATs and environmental information from the general tagging location, we established parameters to infer mortality for Atlantic bluefin tuna using only daily summary data. We then deployed 22 PSATs, programmed to pop off after 31 days (thus providing 30 full daily summaries), on Atlantic bluefin tuna caught using light tackle off the coasts of Massachusetts and North Carolina, USA, in 2015 and 2016. Data were recovered for 15 tags with deployments ranging from 7 days (premature shedding) to 95 days (failed pop-off) and indicated that tagged fish spent sufficient time near the surface to keep the solar-powered tags fully charged. Fourteen fish demonstrated strong temporal changes in temperature indicating vertical movement in the water column, consistent with survival. One fish was predated upon after 17 days, likely by a shortfin mako, and was considered a natural mortality, resulting in a post-release mortality estimate of 0%. Conclusions While low reporting rates complicated inferences about post-release mortality, the concept of using species-specific mortality parameters coupled with a reduced dataset shows promise as a cost-effective tool for detecting post-release mortality using PSATs. In addition, findings suggest that catch-and-release angling is a viable conservation strategy for juvenile Atlantic bluefin tuna caught in the US east coast light-tackle fishery.

Even under current sea level conditions, many communities are working to protect their coastlines against flooding and shoreline erosion. Coastal communities often protect their shorelines against excessive erosion by using armoring techniques (e.g., bulkheads, riprap). Yet hardened structures reduce many of the natural adaptive mechanisms present in coastal ecosystems and reduce the sustainability of the coastal system. In contrast, natural and nature-based features (e.g., living shorelines) can better protect coastal properties from storm damage and reduce erosion while also having the potential to adapt to new conditions. Since property owners are installing armoring structures more often than living shorelines, we sought to understand the factors motivating their shoreline modification decision. We surveyed property owners in Virginia, U.S. that applied for a shoreline modification permit. Most property owners, regardless of modification sought, perceive riprap revetment to be effective, able to withstand storm damage, and able to adapt to sea level rise. Interestingly, property owners that sought out living shorelines were not highly confident in living shorelines’ protection benefits. While most property owners perceived the ecological benefits of living shorelines, these benefits did not substantially impact the decision over what type of shoreline modification to implement. Our work highlights pathways that can improve coastal resilience given the important role that shoreline property owner decisions contribute to coastal community resiliency. Our results indicate there is a need to better engage property owners about the protection and adaptation benefits of living shorelines as their perceptions were not aligned with scientific assessments of living shorelines. Concurrently, coastal policies could be strengthened to support more natural approaches to shoreline management, as the more common armoring techniques are not resilient to sea level rise or storm damage.

The Atlantic surfclam Spisula solidissima fishery, which spans the U.S. Northeast continental shelf, is among the most exposed to offshore wind energy development impacts because of the overlap of fishing grounds with wind energy lease areas, the hydraulic dredges used by the fishing vessels, and the location of vessel home ports relative to the fishing grounds. The Atlantic surfclam federal assessment survey is conducted using a commercial fishing vessel in locations that overlap with the offshore wind energy development. Once wind energy turbines, cables, and scour protection are installed, survey operations within wind energy lease areas may be curtailed or eliminated due to limits on vessel access, safety requirements, and assessment survey protocols. The impact of excluding the federal assessment survey from wind energy lease areas was investigated using a spatially explicit, agent‐based modeling framework that integrates Atlantic surfclam stock biology, fishery captain and fleet behavior, and federal assessment survey and management decisions. Simulations were designed to compare assessment estimates of spawning stock biomass (SSB) and fishing mortality (F) for scenarios that excluded the survey from (1) wind energy lease areas or (2) wind energy lease areas and potential wind energy lease areas (“call areas”). For the most restricted scenario, the simulated stock assessment estimated 17% lower SSB relative to an unrestricted survey, placing it below the SSB target. The simulated F increased by 7% but was still less than the accepted F threshold. Changes in biological reference points were driven by the inability to access the Atlantic surfclam biomass within the wind energy lease areas. Deviations in reference points reflected the proportion of the population excluded from the survey. Excluding the Atlantic surfclam assessment surveys from the regions designated for offshore wind development can alter long‐term stock assessments by increasing uncertainty in metrics that are used to set fishing quotas.

Rising water temperatures along the northeastern U.S. continental shelf have resulted in an offshore range shift of the Atlantic surfclam Spisula solidissima to waters still occupied by ocean quahogs Arctica islandica. Fishers presently are prohibited from landing both Atlantic surfclams and ocean quahogs in the same catch, thus limiting fishing to locations where the target species can be sorted on deck. Wind energy development on and around the fishing grounds will further restrict the fishery. A spatially explicit model of the Atlantic surfclam fishery (Spatially Explicit Fishery Economics Simulator) has the ability to simulate the consequences of fishery displacement due to wind energy development in combination with fishery and stock dynamics related to the species' overlap with ocean quahogs. Five sets of simulations were run to determine the effect of varying degrees of species overlap due to Atlantic surfclam range shifts in conjunction with fishing constraints due to wind farm development. Simulations tracked changes in relative stock status, fishery performance, and the economic consequences for the fishery. Compared to a business‐as‐usual scenario, all scenarios with less‐restrictive fishing penalties due to species overlap exhibited higher raw catch numbers but also greater reductions in revenue and increases in cost after the implementation of wind farms. This analysis serves to demonstrate the response of the Atlantic surfclam fishery to combined pressures from competing ocean uses and climate change and emphasizes the potential for economic disruption of fisheries as climate change interacts with the evolution of ocean management on the continental shelf.

Catch share management is a common and increasingly relied upon form of fisheries management in which, frequently, shares of a hard total allowable catch are allocated to individuals or groups of harvesters. A style of rights-based-management, catch shares are often thought to promote efficient resource use and long-term stewardship, improving both economic and ecological conditions within the fishery. Their success in multispecies fisheries, where non-selective gear captures several, separately managed stocks, has been the subject of ongoing debate however. Limited flexibility in production might dampen or entirely remove any and all of catch shares' potential benefits as harvesters are unable to effectively target or avoid individual stocks. In this dissertation, I explore the economic effects of multispecies catch shares following a 2010 application to New England groundfish, a diverse and overexploited multispecies fishery. In the first chapter, I combine market models of ex-vessel inverse demand and counterfactual models of individual harvesting behavior to estimate the market timing benefits of catch share management. I find that fleet revenues were improved by over US$30 million and that individual benefits were heterogeneously distributed, with large and more diverse operations better able to take advantage of market externalities. In the second chapter, I theoretically develop and empirically explore a model of costly avoidance wherein production of target stocks is given up to reduce that of the avoided. An error in the management of pollock, initially setting a low and constraining allocation that was later relaxed, is used to identify behavioral response to multispecies production constraint, finding harvesters engaged in costly avoidance strategy, which had the low pollock allocation persisted, would have cost the fleet US $ 3 million. I then develop a neoclassical multispecies production technology in the third chapter which is used to test technological restrictions of strong disposability on pairs of demersal species and also estimate the costs, in terms of forgone production, of pollock avoidance. For catch share regulated species, strong disposability is rejected more than half the time, suggesting output controls may frequently lead to choked production. Additionally, pollock avoidance costs are estimated at US $6 million.