Fisheries are among the most complex and tightly coupled social-ecological systems. This thesis develops new perspectives on the spatial features of fisheries, and on common pool resources in general. The central model of the work is the Distributed Commons, a commons spread across space with local and cross-boundary interactions. The model is founded in evidence from historical analysis and complexity theory, and offers insights for management and broader sustainable development policy. The second part of the thesis uses empirical analysis, applying Bayesian and econometric techniques, to study the spatial features exposed by the model. Finally, a computational model is calibrated for exploring the consequences of this theory through experiments. The implications of the Distributed Commons model are relevant to many areas of sustainable development, including atmospheric pollution, environmental degradation, and the use of ecosystem resources.

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Thesis (M.A.)--University of Florida, 2002. / Title from title page of source document. Document formatted into pages; contains xi, 203 p.; also contains graphics. Includes vita. Includes bibliographical references.

This thesis comprises three essays on the management of nonrenewable resources. Pollution is often associated with the use of nonrenewable resources. Indeed, many of today's most pressing environmental problems are caused by these types of activities. Despite the connection between nonrenewable resource use and environmental degradation, the two issues have been, for the most part, analysed separately by economists. The first paper develops a framework to analyse the effects of a pure-flow externality on the competitive allocation of nonrenewable resources. For commonly- used specifications of consumer preferences, the competitive allocation is found to be fully optimal for pure-flow externalities exhibiting decreasing marginal disutility. Hence, the paper shows that the presence of a negative externality associated with the use or extraction of a nonrenewable resource need not result in inefficiency. The US 1990 Oil Pollution Act is the most significant attempt yet made by a nation to deal with pollution of its territorial waters. It significantly altered the rights and obli gations of tanker owners operating in US waters, effectively introducing unlimited liability and significantly expanding the definition of spill damages. The second paper analyses the effect of the Act on major pelagic oil spills occurring world wide. The hypothesis that the Act had a negligible effect on the number of spills occurring in North America's coastal waters is tested empirically. The results indicate that the Act significantly reduced the number of spills occurring in North American coastal waters and has had no discernible effect on spill frequencies elsewhere. There is a keen and growing interest in the properties of vertical relationships governing the pricing and transfer of intermediate goods. The third paper examines an unusual and commercially-important vertical relationship — the price participation system —which is used extensively in the zinc industry. The paper explores the conjecture that significant demand uncertainty and risk aversion on the part of zinc smelters might explain why the industry uses the price participation system rather than a more conventional contractual arrangement. The results indicate that these factors do go part way toward explaining why the industry uses the price participation system.

Marine spatial property rights reduce many common pool externalities that plague wild capture fisheries and incentivize productive use for aquaculture. Specifically, Territorial Use Rights for Fisheries (TURFs) are a management tool whereby individuals or groups are granted exclusive access to harvest resources within an area, and are the prevailing management of coastal fisheries in Chile. Additionally, secured spatial property rights appear inherently obligatory for aquaculture development; i.e., private leases in Virginia, where submerged grounds granted to an individual or a company for oyster production are considered a form of TURF. Although the number and extent of spatially managed areas are the highest they have ever been in both systems, the impacts of spatial property rights on fisheries and aquaculture sustainability are still not fully understood. The objective of this dissertation was to evaluate current challenges to the effective use of TURFs, deepening our understanding of their efficacy for fishery and aquaculture management. The long-term impacts of the Chilean TURFs network on harvests of benthic resources was investigated both inside and outside TURFs (Chapter 2). Although catch rates were significantly higher inside TURFs than surrounding open access areas, they appeared to be decreasing over time, and, though limited, the impact of TURFs on catches in open access areas was negative. Spatio-temporal trends in private lease use and productivity in Virginia were examined to identify challenges faced by the oyster aquaculture industry. Constraints to aquaculture expansion were investigated by evaluating whether a lack of space limits aquaculture development as well as the extent and drivers of lease non-use (Chapter 3). Limited evidence of spatial constraints was found, although results suggest additional social and regulatory limiting factors. While rates of lease use and productivity increased from 2006 to 2016, only 33% of leases were ever used for oyster production. The non-used leases were potentially held for exclusionary or speculative uses. Additionally, Virginia had the second lowest levels of total production of cultured oysters per leased acre among the states along the U.S. East and Gulf coasts, confirming significant limitations associated with the current leasing system. Production frontier models were used to quantify lease use efficiency (i.e., utilization of space given the underlying environment) for oyster production (Chapter 4). Significant amounts of inefficiency in intensive aquaculture practices suggest that production could increase by at least 64% per lease, on average (though high heterogeneity is observed between leases). Low levels of use efficiency (i.e., underutilization) imply that leaseholders tend to lease more area than needed, likely due to the low annual lease costs and the absence of enforced production requirements. The number of leases held per leaseholder increased use efficiency, whereas leases in more populated areas were less efficiently used. This research contributes to a better understanding of TURF's efficacy and challenges in Chile and in Virginia. Overall, socioeconomic and management factors appear to be limiting productivity and sustainability of TURFs in both systems, recognizing the importance of incentives, enforcement, zoning, and the potential presence of trade-offs between economic, social and biological sustainability.

This thesis comprises three essays on the management of nonrenewable resources. Pollution is often associated with the use of nonrenewable resources. Indeed, many of today's most pressing environmental problems are caused by these types of activities. Despite the connection between nonrenewable resource use and environmental degradation, the two issues have been, for the most part, analysed separately by economists. The first paper develops a framework to analyse the effects of a pure-flow externality on the competitive allocation of nonrenewable resources. For commonly- used specifications of consumer preferences, the competitive allocation is found to be fully optimal for pure-flow externalities exhibiting decreasing marginal disutility. Hence, the paper shows that the presence of a negative externality associated with the use or extraction of a nonrenewable resource need not result in inefficiency. The US 1990 Oil Pollution Act is the most significant attempt yet made by a nation to deal with pollution of its territorial waters. It significantly altered the rights and obli gations of tanker owners operating in US waters, effectively introducing unlimited liability and significantly expanding the definition of spill damages. The second paper analyses the effect of the Act on major pelagic oil spills occurring world wide. The hypothesis that the Act had a negligible effect on the number of spills occurring in North America's coastal waters is tested empirically. The results indicate that the Act significantly reduced the number of spills occurring in North American coastal waters and has had no discernible effect on spill frequencies elsewhere. There is a keen and growing interest in the properties of vertical relationships governing the pricing and transfer of intermediate goods. The third paper examines an unusual and commercially-important vertical relationship — the price participation system —which is used extensively in the zinc industry. The paper explores the conjecture that significant demand uncertainty and risk aversion on the part of zinc smelters might explain why the industry uses the price participation system rather than a more conventional contractual arrangement. The results indicate that these factors do go part way toward explaining why the industry uses the price participation system. / Business, Sauder School of / Graduate

The Atlantic coast striped bass fisheries collapsed in the late 1970's due to recruitment overfishing and poor habitat quality. Recovery of the fisheries in 1995 resulted from protection of mature females, favorable environmental conditions, and several years of strong recruitment. Today, the striped bass stock is overfished. The purpose of this study was to examine recruitment characteristics of juvenile striped bass during the pre- and post-recovery periods through (1) a comparison of mortality and hatch-date distribution between periods, and (2) to examine growth metrics of individuals from the post-recovery year classes. Lengths and otolith-derived daily ages from juvenile striped bass representing three year classes (2011, 2016, and 2017) from the James and Rappahannock subestuaries of the Chesapeake Bay were used to develop subestuary-specific age-length keys. Daily ages of juvenile striped bass from 32 year classes (1986 to 2017) spanning the pre- and post-recovery periods were projected from the age-length keys. Together with count data, the projected daily ages were used to estimate instantaneous daily mortality rates (Z, day-1) for each year class. Although daily Z estimates were relatively constant among the 32 year classes, mean hatch dates shifted earlier today (1996 to 2017) than prior to 1995. Within the post-recovery year classes, daily growth in length and weight was examined along with body condition (Fulton's K). All growth metrics varied by year class and subestuary, but daily growth rates and body condition were inversely related. The results of this study indicate that recruitment dynamics of juvenile striped bass in the Virginia portion of the Chesapeake Bay have changed over time, and within the post-recovery year classes, those changes varied among fish from the James and Rappahannock subestuaries.

Atlantic bluefin tuna (Thunnus thynnus) are targeted by recreational anglers along the east coast of the United States, and the fishery is thought to be of considerable economic value. However, limited knowledge of the preferences and values of fishery participants impedes the ability of managers to maximize fishery benefits and predict harvest patterns, while an incomplete understanding of post-release mortality hinders efforts to estimate total mortality resulting from the fishery. This dissertation used a multidisciplinary approach that relied heavily on cooperative research with the recreational fishing community to examine these questions. A stated choice survey of private anglers permitted to target bluefin tuna (Chapter II) estimated a fishery consumer surplus of over $14 million in 2015 while revealing striking heterogeneity in angler preferences. Respondents placed a high value on harvesting bluefin tuna, but about half of anglers also valued non-consumptive aspects of bluefin tuna fishing such as catch-and-release. Preference segmentation was largely driven by income and recent bluefin tuna targeting behavior, with high-income anglers who had recently targeted bluefin tuna more likely to belong to the non-consumptive group. These results indicate that liberalization of harvest regulations could result in significant, non-linear increases in effort and harvest should consumptive-oriented anglers decide to re-enter the fishery. A second survey, of Atlantic bluefin tuna fishermen who possess a permit enabling them to fish either commercially or recreationally on a trip-by-trip basis, applied an online contingent sequential stated choice approach to better understand the decision-making of this unique group (Chapter III). Responses indicated that, while some permit holders consistently fish either recreationally or commercially, a substantial proportion of participants change trip type depending on fishery conditions such as prevailing fish size or regulations. The changing behavior of this latter group could potentially result in large shifts in targeting and lead to overages for the commercial handgear sector or recreational sector, and potentially the U.S. bluefin tuna quota as a whole. Lastly, post-release mortality was estimated for juvenile bluefin tuna caught in the increasingly popular light-tackle recreational fishery while also beta testing a newly developed, solar-powered pop-up satellite archival tag designed to enable large-scale, high-precision mortality studies (Chapter IV). Data were only obtained for 15 of 22 deployed tags, with 14 fish demonstrating behavior consistent with survival. One fish was predated upon, likely by a shortfin mako shark, after 17 days, and this was considered a natural rather than a fishing mortality. The low level of estimated post-release mortality, consistent with results from previous studies on different size classes of bluefin tuna caught with various angling gear types, suggests that catch-and-release angling, which Chapter II showed to be highly valued by some anglers, is a viable conservation strategy. Overall, this dissertation provides information regarding both angler preferences and fishery impacts that are of direct relevance to management. Future efforts should be directed to further engaging the recreational bluefin tuna fishing community in order to improve buy-in to management strategies and improve the ability of the United States to maintain fishing mortality within internationally prescribed limits.

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Pacific halibut (Hippoglossus stenolepis) is a prohibited species for the U.S. West Coast Bottom Trawl Fishery and in the last decade, there has been a concentrated interest in the use of artificial illumination serving as a potential bycatch reduction device. Previous studies conducted off the coast of Oregon have found that the addition of green light-emitting diodes to the bridles of low-rise, cutback trawls greatly reduced the number of Pacific halibut caught. However, recent regulation changes now permit high-rise trawls, a gear configuration that fishes a very different volume of water than the previously permissible gear profile, in areas where they were once prohibited. No study to date has investigated the efficacy of artificial illumination to reduce Pacific halibut bycatch for this configuration. Field trials for this study were conducted off the Oregon Coast during August of 2022 and were designed to test a high-rise bottom trawl fitted with artificial illumination as a means to potentially reduce Pacific halibut bycatch. Length-dependent catch comparison and catch ratio analyses for trawls with and without illumination were conducted to determine if catches of Pacific halibut and three commercially important groundfish species differ between trawl treatments. Somatic fat content of Pacific halibut and physiological indicators of stress were also assessed via blood plasma samples to determine if there was a difference in physiological condition between Pacific halibut captured in either illuminated or non-illuminated tows. Additionally, an ethogram was constructed to quantify Pacific halibut behavior in response to an approaching high-rise trawl. Analyses were based on a simulated dataset based on previous flatfish behavioral studies and qualitative evidence from video and sonar recordings collected during field trials. While illuminated trawls caught fewer individuals than the non-illuminated trawls for all species in this study, the difference in catch was not statistically significant. Total catch size was found to have a significantly positive effect on glucose and lactate levels for Pacific halibut; however, no statistically significant differences between illuminated and non-illuminated tows were exhibited across all of the physiological parameters assessed in this study. I hypothesize that this lack of difference between treatment groups may have resulted from the change in gear configuration as Pacific halibut are more likely to rise off of the seafloor when responding to an approaching net. The higher headrope orientation used in a high-rise trawl configuration may be presenting too much of a challenge for halibut seeking to avoid the path of the trawl. It is also possible that the location of the lights was insufficient in triggering a change in avoidance behaviors. These findings are contrary to prior evidence and could have potential implications for the industry. Further investigation into Pacific halibut behavior is implored.