Virginia is the east coast's largest producer of eastern oysters and produces more than any other state. As the industry grows to meet increasing demand, more conflicts have arisen with other resource users, especially waterfront property owners. Some landowners claim oysters impact recreational and aesthetic uses of their property, therefore lowering the value of the home. Using a hedonic property value model, this study examines the effect of oyster aquaculture on waterfront properties by using 2,245 property sales from 16 counties and independent cities and information on aquaculture activity from 2012-2016. The results suggest that oyster aquaculture has a positive effect on waterfront property values, but a negative effect when using cage equipment. / Master of Science / Virginia is the east coast’s largest producer of eastern oysters and produces more than any other state. As the industry grows to meet increasing demand, more conflicts have arisen with other resource users, especially waterfront property owners. Some landowners claim oysters impact recreational and aesthetic uses of their property, therefore lowering the value of the home. This study examines the effect of oyster aquaculture on waterfront properties. The results suggest that oyster aquaculture has a positive effect on waterfront property values, but a negative effect when using cage equipment.

Sea-bed benthic-invertebrate assemblages of species within and proximal to an existing mussel farm off Taniwhanui Point, eastern Waiheke Island, are reported. Substratum type, whether predominantly mud, gravels or an admixture of the two, mud/gravels, is shown to influence infaunal species assemblage composition; the bivalve Theora lubrica, ostracods, amphipods and polychaetes characterise muddy substrata; polychaetes, particularly spionids and syllids, ostracods, amphipods, bivalves and ophiuroids characterise mud/gravel substrata; and diverse assemblages of polychaetes, bivalves, pagurid crabs, gastropods, ostracods, ophiuroids and nemertean worms characterise gravel substrata. Significant differences in sea-bed assemblages are reported along one transect inside and outside the farm over the three seasons during which surveys were conducted, summer, autumn, winter of 2008. Along the northern side of the mussel farm those sediments beneath the farm are characterised by greater abundances of polychaetes and crustaceans (Malacostraca), whereas sediments outside the farm are characterised by greater abundances of bivalves and ostracods. Sediments both inside and outside the north-eastern border of the farm during summer are characterised by similar abundances of polychaetes, bivalves and ostracods. Similarly, those sediments within and outside the farm along its southern border during summer are characterised by abundances of polychaetes, bivalves, crustaceans (Malacostraca) and gastropods. Measures of relative abundance, rarity and species richness are applied to sea-bed assemblages off eastern Waiheke Island to enable an appraisal of the spatial distribution of each within and outside the farm, and throughout the eastern Waiheke Island region. One of these measures, relative abundance, is then compared with other, albeit limited abundance data from previous soft-sediment surveys conducted throughout Hauraki Gulf. The most species rich and abundant sites off eastern Waiheke Island occur in gravelly substrata between Waiheke Island and Pakatoa Island, and between Rotoroa and Ponui Islands, in addition to beneath the southern portion of the existing mussel farm. Gravel-based substrata are recognised to be the most species rich and densely populated with invertebrates for this sediment type in Hauraki Gulf. Similarly, the muddy substrata off eastern Waiheke Island region appear to host more individuals and species than any other reported muddy substratum in Hauraki Gulf. The existing mussel farm is shown to significantly affect sea-bed communities, but in a manner that has not been previously reported in New Zealand. Species richness and abundance are greater beneath the farm, as are the proportions of very rare and uncommon taxa to more common and ubiquitous taxa. Sediments beneath the farm are not characterised by elevated abundances and richness of opportunistic species; and no obvious difference in sediment grain size is apparent along a transect extending from 20 m inside the farm to at least 110 m outside it. The biological footprint of the farm is limited, appearing to extend no further than 20 metres from the northern physical boundary of the farm; the gross sedimentary characteristics (grain size) do not differ significantly within and outside the farm. Within and immediately outside the farm species richness and abundance tend to increase during colder seasons; beneath the farm, species richness (d), abundance (N), Shannon index (H’) and Simpson index (1-λ’) were higher during May (autumn) and August (winter) than during February (summer); diversity values outside the farm were similar during summer and autumn, but species richness (d), evenness (J’), Shannon index (H’) and Simpson index (1-λ’) were all greater during winter. No opportunistic taxa are considered to be appropriate indicators of organically enriched environments, at least enrichment that can be intuitively linked to any direct effect of the existing mussel farm. One species, the heart urchin Echinocardium cordatum, only rarely occurs inside the physical farm boundary, so its relative abundance renders it an appropriate indicator species of mussel-farm impacts.

Marine aquaculture has become one of tendencies as many countries aware of that the marine resources are not in the sustainable development from the threat of over fishing. Marine aquaculture will eventually replace the world fishing harvest as being a major stream industry in the future. Meanwhile, fast growing marine aquaculture has caused the potential problems in marine environment. A successful marine aquaculture must rely on comprehensive environmental information and monitoring, including well-designed planning and management scheme. This study research the suitable environmental indicators to predict the impact of marine environment related to marine aquaculture including comprehensive environmental data information and suitable modeling. The use of approaches consists of environmental monitoring program (EMP), sediment metals, organic carbon, redox potential, and sulfide as indicators. The survey results at Chuwan and Erkan of Penghu Island showed that sediment, redox potential, and sulfide are important environmental indicators with exception of metals. Under water survey showed that Chuwan and Erkan sites have no major accumulation of wastes from cage aquaculture operation. The current flow of these sites is downstream outward to the sea that results no serious deposition of wastes. These influence the geochemical composition and sediment, suggesting the complexity of marine environmental problems on the use of environmental indicators for monitoring and assessing the impacts. Because of the special environmental condition, we have used the geographic information system (GIS) to evaluate the affect and condition of marine cage sites. The survey results will be useful for farming management strategies and environmental carrying capacity to reduce the risk of cage farming or to accomplish the guidelines and sustainable development of marine aquaculture. This research also reports the economic effective analysis on major farming operators in Penghu, include the data envelopment analysis (DEA), to measure the variables of production inputs and outputs related to farming operation. The evaluation on the relationship of variable products should be useful in the operation and data management of cage farming. The regulations on marine aquaculture are also made to compare with Norway, United States, Japan, China, and Canada.

Sea-bed benthic-invertebrate assemblages of species within and proximal to an existing mussel farm off Taniwhanui Point, eastern Waiheke Island, are reported. Substratum type, whether predominantly mud, gravels or an admixture of the two, mud/gravels, is shown to influence infaunal species assemblage composition; the bivalve Theora lubrica, ostracods, amphipods and polychaetes characterise muddy substrata; polychaetes, particularly spionids and syllids, ostracods, amphipods, bivalves and ophiuroids characterise mud/gravel substrata; and diverse assemblages of polychaetes, bivalves, pagurid crabs, gastropods, ostracods, ophiuroids and nemertean worms characterise gravel substrata. Significant differences in sea-bed assemblages are reported along one transect inside and outside the farm over the three seasons during which surveys were conducted, summer, autumn, winter of 2008. Along the northern side of the mussel farm those sediments beneath the farm are characterised by greater abundances of polychaetes and crustaceans (Malacostraca), whereas sediments outside the farm are characterised by greater abundances of bivalves and ostracods. Sediments both inside and outside the north-eastern border of the farm during summer are characterised by similar abundances of polychaetes, bivalves and ostracods. Similarly, those sediments within and outside the farm along its southern border during summer are characterised by abundances of polychaetes, bivalves, crustaceans (Malacostraca) and gastropods. Measures of relative abundance, rarity and species richness are applied to sea-bed assemblages off eastern Waiheke Island to enable an appraisal of the spatial distribution of each within and outside the farm, and throughout the eastern Waiheke Island region. One of these measures, relative abundance, is then compared with other, albeit limited abundance data from previous soft-sediment surveys conducted throughout Hauraki Gulf. The most species rich and abundant sites off eastern Waiheke Island occur in gravelly substrata between Waiheke Island and Pakatoa Island, and between Rotoroa and Ponui Islands, in addition to beneath the southern portion of the existing mussel farm. Gravel-based substrata are recognised to be the most species rich and densely populated with invertebrates for this sediment type in Hauraki Gulf. Similarly, the muddy substrata off eastern Waiheke Island region appear to host more individuals and species than any other reported muddy substratum in Hauraki Gulf. The existing mussel farm is shown to significantly affect sea-bed communities, but in a manner that has not been previously reported in New Zealand. Species richness and abundance are greater beneath the farm, as are the proportions of very rare and uncommon taxa to more common and ubiquitous taxa. Sediments beneath the farm are not characterised by elevated abundances and richness of opportunistic species; and no obvious difference in sediment grain size is apparent along a transect extending from 20 m inside the farm to at least 110 m outside it. The biological footprint of the farm is limited, appearing to extend no further than 20 metres from the northern physical boundary of the farm; the gross sedimentary characteristics (grain size) do not differ significantly within and outside the farm. Within and immediately outside the farm species richness and abundance tend to increase during colder seasons; beneath the farm, species richness (d), abundance (N), Shannon index (H’) and Simpson index (1-λ’) were higher during May (autumn) and August (winter) than during February (summer); diversity values outside the farm were similar during summer and autumn, but species richness (d), evenness (J’), Shannon index (H’) and Simpson index (1-λ’) were all greater during winter. No opportunistic taxa are considered to be appropriate indicators of organically enriched environments, at least enrichment that can be intuitively linked to any direct effect of the existing mussel farm. One species, the heart urchin Echinocardium cordatum, only rarely occurs inside the physical farm boundary, so its relative abundance renders it an appropriate indicator species of mussel-farm impacts.

Taiwan marine cage aquaculture originated in Penghu and has been developed over 25 years. The expansion of marine cage scale has caused ecological impacts such as enrichment and changes in marine cage sustainable development. The object of this study is to investigate the approaches for assessing the condition of marine cage aquaculture sediment and impacts in Chaiyuan, Penghu. Study methods including cumulative depth and deposit rate of sediment, heavy metals (Cr, Cu, Ni, Pb, Zn, As, Al, Fe, Mn), sulfide, Redox, and Total Organic Carbon were carried to investigate the impact of environment in marine cage aquaculture. Furthermore, Principal Component Analysis (PCA) and Cluster Analysis were implemented to determine the trend of impact distance and depth within the cage areas. This result shows that the average cumulative depth of sediment is approximately 49cm. Cumulative depth and deposit rate of sediment are positive related. The deposit rate of sediment is 0.061g/cm2 per day that is faster than cage farming areas in other countries. The monitoring results from Chaiyuan had the higher concentration of heavy metal than non-farming area. This suggests that the sediment in Chaiyuan has seriously impacted by the cage waste deposition. In particular, higher values of Cr and Ni could be resulted from the discharge of other sources that is needed for further study. High concentration of sulfide was observed under farming cage, Redox from all sites are negative, and the amount of total Organic Carbon is many times than non farming areas. Those conclude that the sediment in Chaiyuan has faced significant III degradation and over its carrying capacity. Contamination of Heavy metal is detected on all the monitoring sites over the farming areas. The higher concentration of heavy metal was observed at the deeper water. The distance, depth and distribution of heavy metal have closely inter-relationships. This study also attempts to provide the approaches of mitigation for improving the farming environment, for example, 1) the authorization should assist farmers in dealing with waste disposal. 2) Implementation of rotation cage farming scheme and integrated multi-trophic aquaculture. 3) Assessment of marine cage carrying capacity and impact to the environment. Those questions should be all taken into concern to achieve the economic and environment sustainable development in the future.

The aquaculture is the fastest growing food source globally, 47% of the aquatic food supply in the whole world came from aquaculture, may exceed 60% 20 years later, but aquaculture under the situation of sustainable development and environmental protection with surging consciousness in the coastal wetland inland, developments are also contracted by limit factors, Marine culture become an important way of development in the future, certainly will become the mainstream of future fishery. Taiwan, surround by sea, the area shallower than 30 meters of depth offshore (include the intertidal zone) is up to 300,000 hectares, is possessed of excellent aquatic aquacultural technique backgrounds, with both traditional and prospective aquacultural type at the same time, suitable for developing marine culture very much. Marine aquaculture of the ¡§demarcated fishing right ¡¨in the Fisheries Act currently, facing the complication and diversity of utilizing in the maritime spaces day by day, uncertainty about fishing right of policy from central government, and confused concept of ¡§title right¡¨, cause the perplexing and dispute of management. The integrated use of GPS, RS and GIS technology, has nearly already applied to every industry field in recent years, in addition, action device technology change with each passing day, let the aspect of 3-S technical application wider and diversification. Management and administration also need to come with the correct idea to marine aquaculture, can just develop sustainablly, it¡¦s necessary to utilize 3-S technology which mellower rapidly, as the tool of management of sea area of demarcated fishery and establish the mechanism and model of management, implement of sea farming, planned production, and the best practice of responsible fishery. This research shows, the government should face marine aquaculture industry squarely again, set up the intact mechanism of management and structure, need to combine and implement with the modern scientific and technological tool, start from each link, use the database platform of integrated 3-S technology, even cooperate with the action device, can offer the improved dynamic management model, and believe that provide the breakthrough reform benefit to development and management of marine aquaculture industry. In order to solve the problem that already been existed for a long time in industry, to set up suitable regulations for management and how to promote making the transition of industry in the future, can't solve all problems by the technological tool only, must still amend the policy and system, both improved in chorus, can offer the good development environment for marine aquaculture. The application of 3-S integrated technology to current demarcated fishing right fishery and future marine aquaculture: 1.Offer a reliable and practical tool for traditional demarcated fishing right fishery administration ; 2. An essential dynamic database of marine aquaculture management in the future; 3. Constructed database in existence must be exactly merged effectively. Should comply with the current tendency of the world, establish the marine functional zoning, changing the concept of marine space using: 1. The marine functional zoning system is a world trend; 2. Set up a sustainable mechanism of management to use ocean; 3. Break the confused concept of ¡§title right¡¨; 4. Public wealth and pay for marine use. The integrated regulation of marine aquaculture should include: 1. Application and permission of the license to marine space using right; 2. Arrangement of management fund; 3. The items of marine pollution monitoring and the precaution implement; 4.The essential items of health management of the aquatic species cultured; 5. The establishment of the ¡§Traceability System¡¨ and dynamic database; 6. Advancing marine aquaculture insurance; 7. Aquatic food security.

abstract: This dissertation consists of three substantive chapters. The first substantive chapter investigates the premature harvesting problem in fisheries. Traditionally, yield-per-recruit analysis has been used to both assess and address the premature harvesting of fish stocks. However, the fact that fish size often affects the unit price suggests that this approach may be inadequate. In this chapter, I first synthesize the conventional yield-per-recruit analysis, and then extend this conventional approach by incorporating a size-price function for a revenue-per-recruit analysis. An optimal control approach is then used to derive a general bioeconomic solution for the optimal harvesting of a short-lived single cohort. This approach prevents economically premature harvesting and provides an "optimal economic yield". By comparing the yield- and revenue-per-recruit management strategies with the bioeconomic management strategy, I am able to test the economic efficiency of the conventional yield-per-recruit approach. This is illustrated with a numerical study. It shows that a bioeconomic strategy can significantly improve economic welfare compared with the yield-per-recruit strategy, particularly in the face of high natural mortality. Nevertheless, I find that harvesting on a revenue-per-recruit basis improves management policy and can generate a rent that is close to that from bioeconomic analysis, in particular when the natural mortality is relatively low. The second substantive chapter explores the conservation potential of a whale permit market under bounded economic uncertainty. Pro- and anti-whaling stakeholders are concerned about a recently proposed, "cap and trade" system for managing the global harvest of whales. Supporters argue that such an approach represents a novel solution to the current gridlock in international whale management. In addition to ethical objections, opponents worry that uncertainty about demand for whale-based products and the environmental benefits of conservation may make it difficult to predict the outcome of a whale share market. In this study, I use population and economic data for minke whales to examine the potential ecological consequences of the establishment of a whale permit market in Norway under bounded but significant economic uncertainty. A bioeconomic model is developed to evaluate the influence of economic uncertainties associated with pro- and anti- whaling demands on long-run steady state whale population size, harvest, and potential allocation. The results indicate that these economic uncertainties, in particular on the conservation demand side, play an important role in determining the steady state ecological outcome of a whale share market. A key finding is that while a whale share market has the potential to yield a wide range of allocations between conservation and whaling interests - outcomes in which conservationists effectively "buy out" the whaling industry seem most likely. The third substantive chapter examines the sea lice externality between farmed fisheries and wild fisheries. A central issue in the debate over the effect of fish farming on the wild fisheries is the nature of sea lice population dynamics and the wild juvenile mortality rate induced by sea lice infection. This study develops a bioeconomic model that integrates sea lice population dynamics, fish population dynamics, aquaculture and wild capture salmon fisheries in an optimal control framework. It provides a tool to investigate sea lice control policy from the standpoint both of private aquaculture producers and wild fishery managers by considering the sea lice infection externality between farmed and wild fisheries. Numerical results suggest that the state trajectory paths may be quite different under different management regimes, but approach the same steady state. Although the difference in economic benefits is not significant in the particular case considered due to the low value of the wild fishery, I investigate the possibility of levying a tax on aquaculture production for correcting the sea lice externality generated by fish farms. / Dissertation/Thesis / Doctoral Dissertation Biology 2014

L'aquaculture et la pêche impactent l'environnement, les ressources et le fonctionnement des écosystèmes. L’un des enjeux en écologie est de placer ces activités anthropiques dans un cadre de développement durable. Afin de quantifier et de limiter ces impacts, différentes méthodes d’évaluation environnementale ont vu le jour. L’Analyse de Cycle de Vie (ACV) est une méthode pertinente pour évaluer le bilan environnemental d'un produit en prenant en compte l’ensemble de ses étapes de vie, "du berceau à la tombe", depuis l’extraction des matières premières et leurs transformations pour l'élaboration du produit, jusqu’à la fin de vie. Cette thèse porte sur l’adaptation de l’ACV au domaine de l'aquaculture et de la pêche en Tunisie. Son objectif est d'explorer les perspectives offertes par cette méthodologie afin de mieux caractériser le fonctionnement des systèmes de production de poissons et leur lien avec l’environnement. Cette étude a montré que les pratiques aquacoles et la production d'aliment de poisson sont les contributeurs majeurs aux impacts environnementaux, ceci est expliqué par l'utilisation de farine et d'huile de poisson dans la fabrication de l'aliment. Les résultats ont également montré que les impacts du chalutage de fond sont proportionnels à la quantité de carburant nécessaire pour la production. Ce travail a permis d'étudier et comparer les impacts environnementaux de l'activité aquacole et de la pêche au chalutage de fond en Tunisie. Les résultats de cette thèse ont un intérêt pour les gestionnaires en proposant des voies d'amélioration et des recommandations stratégiques de gestion pour améliorer les deux secteurs afin de les placer dans un contexte de développement durable. / The main goal of ecology is to place human activities within a framework of sustainable development by enhancing their economic benefits, their social attractiveness and their environmental performances. Ecosystems that support fisheries and aquaculture are subject to several alterations of significant relevance to their functioning and to their abilities to provide goods and services. Therefore, the long-term sustainability of fishing and aquaculture is a major concern from an environmental and ecological viewpoint. Both activities carry risks of negative environmental impacts because of its close relation with the immediate environment. To better understand environmental impacts and ensure the sustainability of fishing and aquaculture, it is necessary to develop an integrative sciencebased approach to impact assessment. Life Cycle Assessment (LCA) has emerged as a robust method to estimate potential environmental impacts associated with a product. It allows the assessment of environmental impacts “from cradle to grave”, taking into account all stages of a product’s life. This thesis focuses on the adaptation of LCA to demersal trawling and aquaculture in Tunisia. The goal is to explore how LCA improves the environmental evaluation of seafood production systems and how it helps to better understand their links with the environment. Results revealed that rearing practices and fish feed were the greatest contributors to the impacts studied due to the production of fish meal and oil and the low efficiency of feed use. The study also showed that impact intensity of demersal trawling was proportional to the amount of fuel consumed. LCA is a valuable tool for assessing how to improve environmental sustainability of demersal trawling and aquaculture.