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FICANO, GIOVANNA. "Innovative technologies for packaging, preservation, shelf-life extension and traceability of the aquaculture and fishery products." Doctoral thesis, Università degli Studi di Palermo, 2022. http://hdl.handle.net/10447/529110.
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Dewals, Jean-François. "Sustainable food transition and labellling : the case of the frenchfishery and aquaculture products market." Electronic Thesis or Diss., Brest, 2024. http://www.theses.fr/2024BRES0050.
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Cette thèse de doctorat porte sur la consommation des produits de la pêche et de l’aquaculture (PPA). Elle s’intéresse à mieux orienter les consommateurs vers des comportements de consommation plus durables, notamment au travers de l’utilisation des labels. Le marché français est utilisé comme cas d’étude. Cette thèse démontre notamment le caractère non-durable de la consommation française de PPA du point de vue environnemental et santé. Développer l'information et les connaissances des consommateurs envers cette filière est une étape essentielle pour l’adoption de comportements plus vertueux. Si les labels sont un outil pour guider les consommateurs dans leur choix de consommation, cette thèse démontre que les préférences pour ces démarches de labellisation sont aujourd’hui très hétérogènes. Les préférences exprimées sont principalement égoïstes, là où la demande éthique reste, elle, plus secondaire. Ce travail démontre aussi l’influence du caractère littoral sur les préférences exprimées, et sur les connaissances des consommateurs vis-à-vis du secteur des PPA. Finalement, ce travail démontre qu’associer deux labels sur un même produit (un écolabel et une allégation sûreté) n’est pas forcément valorisé par les consommateurs, et que la méthode de production (pêche vs aquaculture) influence les préférences des consommateurs pour ces labelsThis dissertation focuses on the consumption of fishery and aquaculture products (FAPs). The aim of this work is to bettre understand how to guide consulers towards more sustainable consumption, in particular through the use of labels. The French market is used as a case study. This thesis demonstrates the unsustainable nature of French consumption of FAPs from an environmental and health point of view.Improving consumers' knowledge of the FAP sector is essential to guide them towards more virtuous behaviour. Although labels are a growing tool to inform and guide consumers in their consumption choices, this thesis shows that their preferences for these labelling approaches are currently very heterogeneous. Consumer’s preferences remain egoistic, while ethical demand remains secondary.Our work also shows the influence of coastal areas, on consumer’s and knowledge of the FAP sector. Finally, this work is interested in the association between an ecolabel and a safety claim. It shows that the combination of two labels on the same product is not necessarily valued by consumers and that the production method (wild vs. farmed) influences consumers' preferences for these two labels
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Wilde, James D. "Analysis of a niche market for farm-raised black sea bass Centropristis striata in North Carolina." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-3/wildej/jameswilde.pdf.
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Devic, Emilie D. P. "Assessing insect-based products as feed ingredients for aquaculture." Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/24370.
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Research has been actively looking for alternative feed ingredients to reduce the reliance of the aquafeed industry on marine ingredients, namely fish meal (FM) and fish oil (FO). In this context, insects, in particular housefly (Musca domestica) and black soldier fly (BSF, Hermetia illucens) larvae, have been identified as promising candidates. Although a global insect farming industry is emerging, it is for now constrained by regulatory and technical bottlenecks that raise the question ‘where and how insect-based products could be integrated into aquaculture’. The literature indicated a high interspecies variability of the results when replacing FM with insect meals in fish diets and previous work failed to consider the existing challenges related to the insect production to demonstrate commercial relevance and applicability. In this thesis, maggot meals (MM) and frass (insect digestate) were assessed as strategic feed ingredients for two commercially important farmed species: Atlantic salmon, (Salmo salar) and Nile tilapia (Oreochromis niloticus), in their relevant contexts. Case studies showed that both housefly and BSF MM are high quality feed ingredients and suitable alternative to FM. Specifically, dietary inclusions of up to 200 g/kg of crude or defatted housefly larvae meal did not compromised the feed digestibility and utilisation and the growth performance and body composition of salmon parr (freshwater stage), compared to a FM-based control diet. Hormone (17α-methyltestosterone) treated diets containing between 250 and 1000 g/kg BSF or housefly meal were found as effective as a commonly used pure hormone-treated FM in sex-reversal process leading to 99.8 to 100% males, high survival and evenness of the fish produced. In a commercial diet for advanced nursing of Nile tilapia fingerlings, up to 80 g/kg BSF meal was included without impairing the fish performance and body composition; dietary inclusion was limited by the lipid content of the crude MM. Finally, BSF frass derived from brewery spent grains or processed food wastes were found more effective when used as soil bio-fertilisers with minimum application rate of 10.0 tonnes/ha or 5.0 tonnes/ha, respectively (for a spring onion culture), rather than supplemental feeds for tilapia farmed in semi-intensive conditions (fertilised pond). The study also indicated that site-specific conditions should be accounted to support appropriate and sustainable use of insect-based products but in any case, juvenile fish should be strategically targeted given their requirements. It is expected that this approach, could support the sustainable intensification of aquaculture and contribute more broadly to food security whilst contributing to the development of a circular economy.
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Denham, Ainslie M. "Geostatistical spatiotemporal modelling with application to the western king prawn of the Shark Bay managed prawn fishery." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/435.
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Geostatistical methodology has been employed in the modelling of spatiotemporal data from various scientific fields by viewing the data as realisations of space-time random functions. Traditional geostatistics aims to model the spatial variability of a process so, in order to incorporate a time dimension into a geostatistical model, the fundamental differences between the space and time dimensions must be acknowledged and addressed. The main conceptual viewpoint of geostatistical spatiotemporal modelling identified within the literature views the process as a single random function model utilising a joint space-time covariance function to model the spatiotemporal continuity. Geostatistical space-time modelling has been primarily data driven, resulting in models that are suited to the data under investigation, usually survey data involving fixed locations. Space-time geostatistical modelling of fish stocks within the fishing season is limited as the collection of fishery-independent survey data for the spatiotemporal sampling design is often costly or impractical. However, fishery-dependent commercial catch and effort data, throughout each season, are available for many fisheries as part of the ongoing monitoring program to support their stock assessment and fishery management. An example of such data is prawn catch and effort data from the Shark Bay managed prawn fishery in Western Australia. The data are densely informed in both the spatial and temporal dimensions and cover a range of locations at each time instant. Both catch and effort variables display an obvious spatiotemporal continuity across the fishing region and throughout the season. There is detailed spatial and temporal resolution as skippers record their daily fishing shots with associated latitudinal and longitudinal positions. In order to facilitate the ongoing management of the fishery, an understanding of the spatiotemporal dynamics of various prawn species within season is necessary. A suitable spatiotemporal model is required in order to effectively capture the joint space-time dependence of the prawn data. An exhaustive literature search suggests that this is the first application of geostatistical space-time modelling to commercial fishery data, with the development and evaluation of an integrated space-time geostatistical model that caters for the commercial logbook prawn catch and effort data for the Shark Bay fishery. The model developed in this study utilises the global temporal trend observed in the data to standardise the catch rates. Geostatistical spatiotemporal variogram modelling was shown to accurately represent the spatiotemporal continuity of the catch data, and was used to predict and simulate catch rates at unsampled locations and future time instants in a season. In addition, fishery-independent survey data were used to help improve the performance of catch rate estimates.
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Britz, Peter Jacobus 1959. "Adventures with abalone : aquaculture, poaching, and fishery restoration." Rhodes University, Grahamstown, 2011. http://hdl.handle.net/10962/d1018943.
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[From the text] Tonight I am going to tell you about my research on a another mollusc, the humble abalone. - In contrast with the highly evolved squid, this marine snail belonging to the ancient archeogastrod lineage which has a much simpler anatomy and lifestyle. It doesn’t posses a proper brain mass, only having 4 ganglia or nerves knots at the front end. Its two simple eye spots which detect light and dark, a tough shell and a large and extremely powerful foot muscle to adhere to rocks. This simple configuration has served well for over 100 million years.
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Walker, Nicholas Mark. "The fish and fishery of Stocks Reservoir, Lancashire." Thesis, University of Hull, 1989. http://hydra.hull.ac.uk/resources/hull:3812.
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This study of the fish and fishery of Stocks Reservoir, Lancashire, is the result of contract work undertaken by the researcher for North West Water (NWW). In an attempt to describe the location of the study, relevant information covering the catchment, local geology, reservoir construction and flora and fauna is included.The Authority's remit suggested a study of three facets of the catchment, namely, a study of the native fish populations, a monitoring of the recently opened fishery and an analysis of operational filter plate impingement.In order to minimise disturbance of the sport fishery, native fish population work was necessarily limited to the reservoir's three major afferent streams, the River Hodder, Hasgill Beck and Bottoms Beck.As a preliminary measure of tributary stream status, a simple invertebrate site study was undertaken by the researcher in 1985.Fish population work based on catch per unit effort (CPUE) was pursued in the spring, summer and winter of 1985, 1986 and 1987 at 8 sites, employing D. C. electric fishing equipment, whilst Carle and Strub's (1978) MWL Method was adopted for population estimations. The validity of the electric fishing survey and age determination are discussed in the text.The native species of brown trout, bullhead, stone loach and minnow were encountered, as was the introduced rainbow trout. Species densities and the population structure of the native brown trout were examined in detail for each survey site. The River Hodder was revealed to be the least populous tributary, whilst Hasgill Beck exhibited the greatest fish densities. Spawning migrations of native brown trout were evident, with fry recruitment at its optimum at site 4 on Hasgill Beck and site 8 on Bottoms Beck. The waterfall on Bottoms Beck might well have precluded upstream access to the head waters of this tributary. Observed mean brown trout length for age data were similar to those recorded by authors researching other upland stream locations.The history of Stocks Reservoir as a sport fishery is outlined prior to the present leaseholder's opening of the reservoir as a day ticket fly fishery for the 1985 season. The water was stocked predominantly with rainbow trout, together with some brook trout and brown trout before fishing commenced.The present study covering the seasons 1985 to 1987 was based primarily on data abstracted from catch return forms, which displayed a notably high rate of submission, and stocking consent data provided by NWW. The validity of return form data is discussed.Over the three seasons studied, angler patronage was observed to decline by 16%, whilst the number of fish caught and taken also declined by 34.8% and 20.5% respectively. Angler success was similarly observed to decline in accord with the decrease in patronage and catches. Interestingly, there was an increased reliance on introductions of rainbow trout over the period, including larger fish, and by 1987 a cessation in the stocking of other trout species.From correlations observed between environmental parameters and angler patronage, anglers appeared to prefer fishing in dry, sunny conditions, but decreases in angler success occurred during periods of increased water turbidity. Such declines in success also displayed congruity with decreases in angler patronage.From a comparison undertaken with a cross-section of English and Welsh stillwater trout fisheries, Stocks Reservoir was judged to rate poorly, returning the lowest performance data in the upland stocked category.An examination of the stomach and hind gut contents of 127 rainbow trout, 7 brook trout and 8 brown trout caught by anglers, was undertaken in the 1985 and 1986 seasons, and was compared with the reservoir fauna data of Mills, M. L. (1971).A description of the water treatment plant and its operation is delineated, and a pertinent collection of fish impingement and screening literature is included.Impingement data were collated from lst March 1985 to 31st December 1987 from routine and emergency cleaning of the filter plates. After storage in a freezer, the thawed fish were examined chronologically, identified, measured and weighed. During the examinations a random sample of stomach and hind guts was procured, and scales from brown trout were removed for possible future reference.The total annual impingement was observed to vary considerably, although brown trout habitually exhibited the greatest losses, comprising 71%, 64% and 89% of fish impinged annually. Of the introduced species, rainbow trout and brook trout, brook trout were the more susceptible to impingement, but remarkably few rainbow trout were lost considering the number stocked.Rainbow trout and brook trout of medium (150mm to 300mm) and large (>300mm) length classes were impinged, whereas many smaller (<150mm) brown trout were lost, a phenomenon concurrent with the recruitment of juvenile stream fish to the reservoir population.Brown trout in particular exhibited an annual dissimilarity in rates of impingement, probably suggesting that seasonal migration was not causative of their increased impingement.Impingement of rainbow trout showed limited correlation with environmental parameters. In 1985 and 1986, increased impingement of both brown trout and brook trout was significantly correlated with low reservoir levels, and to some extent might be linked to rising values of water turbidity.The collecting of stomach and hind gut samples from impinged fish was discontinued after 1985 because of problems in collection associated with delays in sampling and probable regurgitation of stomach contents. The problem of eye fluke infestation in impinged fish was noted and enumerated as sampling progressed.A brief discussion of further routes of operational fish loss from the reservoir is included.
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Kang, Joon-Seog. "The formulation of an international regime for management of fishery resources in the seas surrounding Korea : with special reference to fishery relation among Korea, Japan, and China." Thesis, University of Hull, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272005.
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Ebil, Syazana. "Assessment of demersal fishery resources in Brunei Darussalam." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/57704/.
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A problem commonly encountered in stock assessments of tropical marine resources in developing countries is data paucity, which invariably results from the lack of both human and economic capacity within the government to implement and maintain programmes for data collection and analysis. With special reference to the demersal fishery of Brunei Darussalam, this thesis examines approaches for extracting useful information from data-poor fisheries to assess the state of resources and inform fishery management actions. By using official fishery statistics, augmented by local ecological knowledge (LEK) obtained from fishers engaged in either the large-scale (LS) or small-scale (SS) fisheries in Brunei, changes in demersal fishery resources over the years were assessed. The sustainability of Brunei’s demersal capture fishery was evaluated in the face of its ongoing development and climate change. Using trophodynamic indicators such as mean trophic level (MTL), Fishing-in- Balance (FiB), trophic spectra (TS) and community structure analyses, LS fishery catches of Brunei between 2000 and 2009 revealed a deteriorating state of the coastal demersal ecosystem. Closer examination of the abundance of overall demersal finfish stocks, using the Catch-Per-Unit-Effort (CPUE) index – standardised for other factors not related to abundance – indicated a declining trend, even when total catches remained stationary, although trends in abundance of the different demersal fish families varied. This rapid significant change in recent years is further supported by fishers’ LEK on relative abundance of Brunei marine resources. The study on LEK has also revealed the ‘shifting baseline syndrome’ (SBS) among currently active fishers and their exploited populations, a phenomenon not previously reported for Brunei fisheries. Findings from the study are synthesised with other information, where a number of key issues and policy options are discussed, and recommendations for the management of the fishery are made. This thesis demonstrates that researchers in data-poor fisheries can utilise different assessment tools, given the resources at their disposal, to assist in the management of marine resources.
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Rocha, Carlos Artur Sobreira. "An investigation of the nature of fishing effort in a mixed fishery." Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293194.
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Wright, Gordon Alan. "Cormorants and the Loch Leven trout fishery." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/1623/.
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Perceived conflicts between piscivorous birds and commercial freshwater fisheries are common, and such a perception exists at Loch Leven, a wetland of international importance for nature conservation and a famous commercial brown trout Salmo trutta fishery, where Great Cormorants Phalacrocorax carbo have been shot in large numbers. This thesis describes the foraging behaviour of cormorants wintering on Loch Leven. It summarises changes in wintering numbers over a 32 year period, and reviews data on fish populations, fish stocking rates, angling catches and angling effort in order to seek evidence of detrimental impacts of cormorants on the fishery, and beneficial effects of large-scale cormorant shooting. Finally, this thesis considers turnover within the wintering cormorant population, and its implications for cormorant control. Cormorants spent most of the time roosting, and a single peak of feeding activity occurred early in the morning. Compared to early or late winter, cormorants showed higher foraging activity during mid-winter. Both solitary feeding and flock feeding were recorded, with flock feeding predominating. Solitary feeding was distributed over a wide area. The intensity of flock feeding was less evenly distributed, with 36% of grid squares not used. Overall, 78% of flock feeding activity took place in 23% of grid squares and 59% took place in 13% of grid squares. The best predictor of both solitary feeding and flock feeding intensity of use was mean water depth. Mean water depth was also the best predictor of winter brown trout distribution, although winter brown trout distribution was not a predictor of either solitary feeding or flock feeding intensity of use.
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Medley, Paul Anthony Hassell. "Interaction between longline and purse seine in the south-west Pacific tuna fishery." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47571.
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Ngoile, M. A. K. "Fishery biology of the squid Loligo forbesi Steenstrup (Cephalopoda: Loliginidae) in Scottish waters." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010097.
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A total of 6512 specimens of Loligo forbesi Steenstrup (Cephalopoda : Loliginidae), obtained from Scottish fishing ports and research vessels during 1984/86, was used to investigate aspects of fishery biology of the species in Scottish waters. L. forbesi exhibits sexual dimorphism in size, males had a larger overall mean size (DML, weight) than females, and for each sex the mean size was larger in those from the north-eastern Atlantic than in those from the North Sea. In length-weight relationship, females had a higher regression slope than males and this relationship for squids from Rockall was significantly different to those from the North Sea. Multivariate analyses on measurements of body parts showed that Rockall squid, also, exhibited less variation in body form but distinct differences from those of the west coast and North Sea. Recruitment of L. forbesi occurred during April/May and November/December, the monthly growth rate after recruitment varied between 12.5 to 28.6mm DML/month for males and 12.5 to 17.5mm DML/month for females; for each sex the November/December cohort had lower growth rate. The logistic growth model best fitted the progression of modes of monthly length frequencies. Age determinations estimated from statolith markings varied from under 3 months for 30mm DML individual to 28 months for 571mm DML male individual. Sex ratio in L. forbesi varied significantly from 1:1 throughout the year with males exceeding females except during winter when the number of females may be equal to/or more than males. Mean size at maturity was 205mm DML for males and 192mm DML for females. Spawning occurred during December to March and the peak spawning period occurred in February throughout the study area. In this species, maturity coefficient and gonad-somatic index were the best indices for identification of spawning season. Fecundity is related to size and the average number of eggs per female was 6500.High proportions of specimens with 'empty' stomach were observed during the winter. The prey of L. forbesi was fish, crustaceans, molluscs and polychaetes in decreasing order of incidence. Identified fish prey were Argentina sphryaena, Trisopterus esmakii, Merlangius merlangus and Ammodytes sp.
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Geheb, Kim. "The regulators and the regulated : fisheries management, options and dynamics in Kenya's Lake Victoria fishery." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336275.
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Maldeniya, Rekha Rasanjani Perera. "Small scale multispecies demersal fishery off Negombo, Sri Lanka : a study of their biology and socio-economics." Thesis, University of Stirling, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365093.
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Lazo, Zamalloa Oxana. "Development of new products from aquaculture fish species." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/471460.
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Europeans are regular consumers of fish and aquaculture products. Therefore, five species of potential aquaculture rearing named: Meagre, Pikeperch, Grey Mullet, Greater Amberjack and Wreckfish were selected for new product development. This work incorporated opinions of both experts and naïve assessors thus, including specific demands and consumer preferences, in selected markets of the European Union (UK, Germany, Spain, France and Italy). Different fish product prototypes were developed from the fish species accordingly with suggested ideas and based on the physicochemical and sensory properties of the selected species. Six of these products were chosen, based on their level of processing and addressed market. Consumers perception of all six of them was also assessed in the five selected countries. As it turned out the image/perception of the different products, differed in an important way between countries, as well as their impact on the product acceptance and purchase probabilityLos pasíses de la Unión Europea son consumidores habituales de productos de acuicultura. Es por ello que, se seleccionaron cinco especies con potencial acuícola: Corvina, Lucioperca, Mújol, Seriola y Cherna para el desarrollo de nuevos productos. Este trabajo incluyó opiniones tanto de expertos como de consumidores habituales, incluyendo asñi demandas específicas y preferencias en mercados seleccionados de la UE (Alemania, España, Francia, Italia y Reino Unido. Se desarrollaron distintos prototipos de productos basados en ideas sugeridas y en las propiedades fisicoquímicas y sensoriales de las especies. Seis de estos fueron seleccionados basados en su nivel de procesamiento y mercado. La percepción de consumidores sobre los productos fue evaluada en los 5 países de la UE.La percepción de la imagen de los productos difirió notablemente entre países, así como en la aceptabilidad e intención de compra
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Johny, P. K. "Marketing channels and price spread of aquaculture products." Thesis, Central Marine Fisheries Research Institute, 1993. http://eprints.cmfri.org.in/11070/1/Johny%20P.K..pdf.
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Shrimps occupy a commanding position in the global market by virtue of its ever increasing demand and competetive international prices. A major advantage of aquaculture is that production can be market oriented as against the production oriented marketing in capture fisheries, A proper understanding of consumer demand and the consumers attitudes is a major pre-requisite in planning a viable aquaculture production programme. The systems and technologies of farming to be adopted will also be governed by the nature of the market. It is also quite obvious that the quality and size at harvest, as well as the methods of processing depends very much on the market. The world market for shrimp has been doubled within the last 10 years and aquaculture race for shrimp has started vigoursly in many parts of the world. As the production increases the market is also expanding every year due to the increase indispensable income of the consumers together with the increased rate of consumption. Commercial shrimp landing in the world is now reportedly stagnating at 1.7 million tonnes and the only alternate means of increasing production is to resort to shrimp culture.
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DI, FRANCO Giulia. "DEFINITION OF INNOVATIVE TECHNOLOGIES FOR MONITORING IMPACT AND BIOREMEDIATION INTERVENTIONS ON MARINE AQUACULTURE." Doctoral thesis, Università degli Studi di Palermo, 2022. http://hdl.handle.net/10447/529112.
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Lyver, André. "Formulation, shelf-life and safety studies on value-added seafood products." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0001/MQ29749.pdf.
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Ngoan, Le Duc. "Evaluation of shrimp by-products for pigs in central Vietnam /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5757-2.pdf.
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Koranteng, Kwame Abu. "The impacts of environmental forcing on the dynamics of demersal fishery resources of Ghana." Thesis, University of Warwick, 1998. http://wrap.warwick.ac.uk/34664/.
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The dynamics of demersal fish species assemblages and stocks on the continental shelf of Ghana, West Africa were investigated using data from trawl surveys conducted between 1963 and 1990, and in relation to marine environmental and nearshore forcing factors. Time series analysis was used to examine the dynamics of the marine environment. Classification and ordination methods were used to identify fish assemblages and to identify factors that determine assemblage formation and dynamics. The response of the identified assemblages to changes in the Ghanaian shelf ecosystem were assessed. Between 1964 and 1992, three distinct environmental time blocks (ETBs) in the continental shelf ecosystem off Ghana were recognised. In the first ETB (i. e. before 1972) sea surface and bottom temperatures were relatively high and salinity was low. The second ETB (1972 - 1982) was characterised by low temperatures, high but stable salinity, reduced rainfall and freshwater input into the sea. In the third ETB (1982 - 1992), the system bore a resemblance to the first block with rising temperatures and decreasing salinity. Six fish species assemblages were identified, namely the supra-thermocline sciaenid and lutjanid assemblages, two sparid assemblages (shallow and deep elements), the deep shelf assemblage and the upper slope assemblage. During ETB I and ETB3, the assemblages were easier to identify using ordination techniques, than during ETB2. Species diversity also decreased during ETB2 especially in waters between 10 and 50 m deep. This behaviour of the assemblagesis attributed to the increase in abundance of Balistes capriscus, a species that dominated the ecosystem for nearly 20 years from about 1971, and the observed environmental changes. The estimated density of demersal fish was higher in the upwelling season than in the thermocline season and decreased from 50 kg ha-1 in 1963-64 to 32.4 kg ha-1 in 1990. The density reached its lowest value of 22.5 kg ha-1 in the period between 1973 and 1977. The potential yield of the total demersal biomass (excluding triggerfish) is estimated to be 36,000 - 55,000 mt per annum. With landed catches exceeding 60,000 mt in some years, it is apparent that the resource is over-exploited. A number of policy options are discussed and recommendations for the management of the fishery are made.
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Schnier, Kurt E. "Economic analysis of spatially heterogeneous resources: The case of the fishery." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280326.
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This dissertation investigates the implication of combining economic and ecological models in an effort to expand our knowledge of the complex problems associated with resource management. The motivation for this research arises from the perceived need to develop a better understanding of how the flow dynamics within a resource affect the efficient management of that resource. Following the introduction, the second chapter experimentally tests the theoretical models of agent behavior in patchy resource environments under both sole-ownership and competitive extraction regimes. In each setting experimental results indicate that subjects over-allocate vessels to regions that possess the greatest rates of emigration within the bioeconomic system relative to the theoretical predictions. This introduces a "spatial externality" because over-harvesting in one region reduces the harvest in the surrounding regions. The third chapter proposes a potential solution to the problems associated with a spatial externality by analyzing the use of marine reserves in the presence of a heterogeneously distributed resource. This is conducted by introducing the presence of biological "hot spots" (areas within a fishery that possess a larger growth potential than the surrounding areas) with spatial rates of migration into the current economic theory. Simulation results indicate that the presence of biological hot spots within a fishery creates an environment within which it is optimal to establish a marine reserve that increases the value of the fishery. The fourth chapter makes use of my earlier experimental and simulation research, which indicate that locational choice and the spatial distribution of effort should affect the management of the fishery. Within this chapter a spatial Heckit model is developed to empirically investigate for the presence of herding behavior among yellowfin sole and Pacific cod fishermen in the Eastern Bering Sea. Econometric results provide support for herding behavior among fishermen within the yellowfin sole fishery. Moreover, fishermen respond to the lagged biomass and spatially weighted biomass signals as significant determinants of locational choice. This results in Lotka-Volterra oscillations in the Pacific cod fishery. In the final chapter of this dissertation, the general findings are concluded and some future avenues of research are discussed.
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Cowing, Daniel Mark. "Optimising commerical practices and developing aquaculture techniques for the Norway lobster (Nephrops norvegicus) fishery." Thesis, University of Hull, 2017. http://hydra.hull.ac.uk/resources/hull:16589.
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The Nephrops norvegicus (referred to as Nephrops) fishery is regarded as one of the most important fisheries around the UK, yet data suggest that landings are declining. The role of hatcheries for other crustacean species has proved useful for stock enhancement and aquaculture. Nephrops larviculture has been relatively unsuccessful, with low survival to post larval stages. This thesis comprises four studies aimed at developing key stages that are important for optimising fishing related practices and the development of aquaculture for this species. In chapter 3, the social behaviour of adult Nephrops is examined in conjunction with physiological parameters. The findings indicate that the behavioural interactions have a physiological cost that is associated with the sex and size of the individual and the opponent. The findings are useful for developing fishing practices and broodstock holding and highlight the complexity of correlating physiological parameters with social stress. In chapter 4, a method for sedating and anaesthetising Norway lobster is investigated and successfully identified. Key behaviours are related to sedation stages as well as to several tested dosages. These techniques could be used to lower stress in Norway lobster during transport and handling. In chapter 5, several diets and feeding frequencies are examined for their potential in increasing larval survival and growth. The highest survival and growth were found in the enriched Artemia diets, with a continuous feeding frequency. Larvae fed on wild zooplankton had lower survival and delayed growth, especially for stage 1 larvae. The addition of probiotics yielded promising results in terms of better survival and less variation when compared to an enriched Artemia diet alone. Survival of larvae was increased to ~40% which is an improvement on previous findings and suggests further investigation for optimising larviculture techniques. In chapter 6, the behaviour of post larvae around an adult burrow and an alternative habitat is investigated. The post larvae showed a preference for entering the burrow when it was unoccupied, but would show vigilant behaviour when it was occupied. The post larvae would also find shelter in alternative habitats such as cobbles, which could be a promising application in future release protocols for this species. The results from the thesis demonstrate that Nephrops aquaculture for stock enhancement can currently take place, and that techniques for holding and transporting broodstock can be improved.
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Yang, Hye-Ran. "Mercury contamination and exposure assessment of fishery products in Korea." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215463.
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Final publication is available at http://www.tandfonline.com/doi/full/10.1080/19393210.2014.968808Kyoto University (京都大学)
0048
新制・課程博士
博士(社会健康医学)
甲第19637号
社医博第70号
新制||社医||9(附属図書館)
32673
京都大学大学院医学研究科社会健康医学系専攻
(主査)教授 木原 正博, 教授 小杉 眞司, 教授 YOUSSEFIAN Shohab
学位規則第4条第1項該当
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Mirera, David Oersted. "Capture-based mud crab (Scylla serrata) aquaculture and artisanal fishery in East Africa- Practical and ecological perspectives : Mud crab ecology and aquaculture." Doctoral thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-32399.
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Mud crab Scylla serrata is a crustacean that spends most of its life cycle in the mangrove environment throughout its range. Fishery and aquaculture of this crab are significant economic activities in coastal areas in the tropics and sub-tropics because of the meat quality and nutritional value. However there is a significant shortage of information on the ecology, fishery and aquaculture of these crabs in sub-Saharan Africa. This impacts the development of a sustainable aquaculture and fishery for the benefit of coastal communities. The present study analyses various aspects of mud crab ecology, fishery, aquaculture and social economics in East Africa using multidisciplinary approaches. The results are given in seven papers based on field and laboratory studies. The study established for the first time that high intertidal mangrove back-flats constitute a key habitat for the earliest instars of S. serrata (4 -30 mm CW). It also showed that diurnal tidal migration behaviour occurs in small juveniles that migrate to sub-tidal habitats during the day, possibly due to variable predation risks. Monthly sampling of juveniles in Kenya and Tanzania indicated continuous recruitment throughout the year. The large numbers of juvenile crabs along mangrove fringes indicate that these habitats could serve as sites suitable for collection of juvenile crabs for aquaculture. However, these areas must also be managed and protected to support the recruitment to the wild crab populations. An assessment of the crab fishery indicated that artisanal crab fishers possess significant traditional knowledge mainly inherited from their parents that enabled them to exploit the resource. Such knowledge could be useful for the development of the aquaculture and in management of the fishery. Mud crab fishing was found to be a male dominated activity, and fishers on foot practiced fishing in burrows at spring low tides. Interviews indicated that the average size of marketable crabs has declined over the years and a weak management system was observed with most fishers operating without a license. Due to the knowledge required regarding the local conditions, fishers are unable to shift to new areas. Furthermore fishers and could not fish at neap tides. Such limitations provide a “natural closure” of the fishery. Also foot fishers cover fairly limited distances in their daily operations, an aspect that can be utilized to effect site-specific management for the fishery if necessary. Laboratory and field experiments indicated that cannibalistic interactions are heavily influenced both by size differences of crabs and the availability of shelter but no significant effect was found for different stocking densities. Such information is of direct importance for crab farmers in East Africa, where seed from the wild are of multiple sizes and there is a need to grade juvenile crabs and provide shelter at stocking to ensure maximum survival. Experimental studies in earthen pond and mangrove pen cultures indicated high mortality rates. Comparing growth in earthen pond and mangrove pen systems indicated that growth rates were generally high in both systems, but significantly lower in pen systems without shelter, suggesting that shelter may have a stronger effect on growth than has been previously thought. Similar to artisanal mud crab fishery, an assessment of small-scale mud crab farming by organized community groups in Kenya indicated low level of women participation. A good knowledge of the market existed among the mud crab farming groups where hotels and exporters offered the highest prices. However there is a need for national policies to be directed to support small-scale aquaculture development by ensuring training and capacity building for women, operation and management of groups, data management and provision of user rights for communities working in the mangrove environment. Market analyses showed that the common market size of crabs in East Africa ranged between 500-1000 g and are thus larger than in Southeast Asia where the average size is reported at 300 g. Prices for mud crabs were over 50 % lower in Tanzania than in other East African countries and most of the profit was earned by middlemen and exporters. Cost revenue analysis showed that it would be more profitable to farm smaller commercial crabs, and develop a market for 300 g crabs to increase the profitability of crab farming in East Africa. Also, the same analyses found that farming large crabs in individual cages, which is the dominant culture form in East Africa today, had very low profitability due to high labor costs and low growth rates. Using a step-wise function of natural growth it was shown that growth rates of S. serrata cultured in cages was 40 % of the growth rates obtained in experimental pond and pen cultures, which were similar to natural growth. Therefore the good performance of grow-out cultures of juvenile mud crabs in earthen ponds and mangrove pens showed a potential to develop into a profitable and sustainable intervention. However, more work is needed to improve survival in culture systems and address the identified limitations of crab seeds and feed to enable development of sustainable mud crab aquaculture in East Africa.
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Shields, Brian Alexander. "Aspects of the ecology of the brown trout (Salmo trutta L.) in relation to management of the fishery on the River Don, Aberdeenshire." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU083141.
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Juvenile trout were found predominantly in the tributaries while older trout and juvenile salmon were found predominantly in the main river. Localised reductions in juvenile salmonid abundance in relation to the degradation of the stream habitat were demonstrated. HABSCORE habitat evaluation models appeared to be reasonably accurate in predicting juvenile salmonid numbers. The recruitment of juvenile trout from a tributary into the main river during spring was assessed by trapping. Predictive models based on environmental parameters accounted for 64% and 78% of the variation in the timing of migration of brown trout and trout smolts respectively. The fecundity of adult sea and brown trout was significantly and positively correlated with the fork length and the somatic weight of the female. Fecundity at a standardised body length varied between the brown trout and sea trout. Survival to hatching, of planted trout eggs was high at sites in the upper part of the catchment but was relatively low at sites in the mid and lower catchment. Low survival rates appeared to be related to a high degree of infiltration of fine organic sediments. Displaced trout failed to return to the home site. Home range estimates were less than 20 metres of stream. Large numbers of small trout were taken by anglers in the past. Recorded catches have decreased since 1980 while the mean weight has increased. Fishing effort was shown to be the most important determinant of catch. A small percentage of the anglers accounted for a disproportionately large percentage of the total catch and fishing effort. The age structure diversity of the catch was reduced in areas where the fishing effort was high.
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Vergara, Castillo Victor Manuel. "Technological change and fisheries development : the case of the Mexican shrimp fishery and shrimp aquaculture." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/70624.
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Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1990.Includes bibliographical references (leaves [113]-116).
by Victor Manuel Vergara Castillo.
M.C.P.
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Newton, Richard W. "Assessing environmental sustainability and value addition opportunities for by-products from aquaculture." Thesis, University of Stirling, 2014. http://hdl.handle.net/1893/21336.
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By-products and mortalities from aquaculture have often posed significant challenges to the industry because of their low value resulting in high costs and environmental impact from their disposal. However increasing interest is being expressed in their utilisation to add value to the aquaculture industry and provide synergies with industries which had previously been in competition with aquaculture. Current and prospective processing by-product and farm mortality utilisation strategies were reviewed along with regulations and standards which aim to control their use and protect against human and animal health hazards. The role of aquaculture and fishery by-products in the supply of fishmeal was investigated and it was found that both sectors had the potential to contribute to increasing global supply. There were significant quantities of processing by-products identified which could be directed to fishmeal manufacture but there were also significant amounts of fish production which were not being processed in some regions and could also add to supplies. Processing by-products from aquaculture species often exceed 50% of the production by mass and therefore their efficient utilisation is of significant importance to the overall performance of the value chain. Their utilisation strategies are diverse and in some circumstances offer the possibility to add significant value. Life Cycle Assessment (LCA) is increasingly being used to inform decision makers and consumers about the environmental performance of goods and services to make choices on best practices and informative decisions on purchasing choices. Current methodology in LCA was critiqued and developed to be used for identifying disproportionate impacts from by-product industries and comparative assessment of the eco-efficiency of value chains from Thai shrimp, Vietnamese Pangasius catfish and Scottish salmon aquaculture. New LCA methodology was developed assessing the eco-efficiency of co-products as a whole and in relation to a tonne of edible yield. Measuring the impact of the by-product industry in relation to their edible yield gave different results to measuring their eco-efficiency between the three study species. It was found that the Thai shrimp value chain was the most eco-efficient when by-products were directed to chitosan and hydrolysate manufacture, but production of the salmon was the least impacting between the species in terms of edible yield. Pangasius was the most environmentally impacting of the three species value chains using both methods. It was also found that the upstream impacts of fish and shrimp production, especially feed manufacture, contributed most to the environmental impact in most circumstances, using both economic and mass allocation. Although the methodology produced interesting results, there were some drawbacks and the data sets also had several gaps which led to some assumptions, which could have skewed the results and interpretation. The cause of mortality for five aquaculture species in five countries and their subsequent utilisation was investigated. It was found that extensive systems were more prone to mortality than intensive systems in many cases. There was a wide range of strategies for mortality utilisation. In countries where by-product industries existed, farmers were often able to sell some of their mortality losses but in other areas, disposal could create health and biosecurity hazards. In conclusion, it was found that both by-products and aquaculture mortalities could be utilised effectively and that the additional impact from their use was low in proportion to the rest of the value chain.
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Lian, P. H. B. "Studies of a model rice-fish fermentation." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376663.
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Mak, Ka Wai. "Novel bioanalytical tests and biosensor systems for detection of cyanide traces in marine fish /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202003%20MAK.
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Horton, Christopher Michael 1973. "Possible limiting factors for a sustainable crappie fishery in the Salt River chain of reservoirs, Arizona." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/278628.
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The dynamics of crappie populations in southwestern reservoirs are not well documented. In order for managers to enhance a crappie fishery, they need to understand the factors that control populations. I examined potential limiting factors for black crappie in 4 sequential reservoirs on the Salt River, Arizona. Only in Roosevelt Reservoir, the uppermost reservoir, were crappie relatively abundant. I identified 3 possible limiting factors. Apache, Canyon, and Saguaro reservoirs lacked sufficient spawning substrates. All 4 reservoirs lacked sufficient cover. Finally, the lower 3 reservoirs are less productive during the fall according to chlorophyll a levels than Roosevelt Reservoir. Low productivity may have resulted in fewer zooplankton and possibly a limited forage base for juvenile crappie. Options such as spawning platforms, artificial cover, fertilization, and stocking are discussed as ways to improve the crappie fishery in these reservoirs.
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del, Campo Barquín Luis Matias. "A bio-socio-economic simulation model for management of the red sea urchin fishery in Chile." Thesis, University of Stirling, 2002. http://hdl.handle.net/1893/69.
Full textAbstract:
This study focused on the management of the red sea urchin Loxechinus albus fishery in Chile. The main objective was to design, construct, implement and assess a computer-based simulation model to analyse the biological effects, socio-economic consequences and spatial dynamics resulting from coastal management plans applied to this resource under the system of AMEBR. This was accomplished by using systems dynamics (SD) and geographical information systems (GIS) modelling, in a process of model development, run, optimisation, sensitivity analysis and risk management, and a series of field-based activities carried out at the cove of Quintay. The GIS model developed for allocating sea urchins restocking sites offered a flexible, cost-effective, user-friendly and descriptive technique for support decision-making on management of this species and other benthic resources. Final site selection for restocking was based on the identification, quantification and selection of higher suitability¦availability combinations (site categories). This map showed 16 different suitability¦availability combinations or site categories, ranging from 4¦100 to 8¦100 (suitability points¦availability %). These had an average of 6.44¦69.37 (covering an area of 82.5 Ha overall equivalent to 81.21% of the study area. This site classification demonstrated high heterogeneity between options, and revealed the full variety of alternatives for decision-making. More importantly, the generally high suitability indexes as well as available area emphasised the prospects for restocking sea urchins in this study area. Over and above of the quantitative outcomes obtained from running the GISRM (suitable and available restocking sites) and the BSESM (alternative strategic management plans), the case study-based analysis made it possible to disclose the wider issues related to the red sea urchin coastal management. These results demonstrated the biological inefficiency of traditional size/seasonal restriction-based approach (macro-scenario 1) for sustainable management of the target species. More importantly, final outcomes strongly suggested that a combination of adaptive restocking-based enhancement activities and flexible exploitation constituted a highly attractive approach (macro-scenario 3) for stock management of this fishery in terms of harvestable stock and related incomes. However from the economic analysis, stocking was also found to be economically unfeasible, being a rather cost intensive exercise negatively affected by high natural mortality rates. A single-variable optimisation analysis demonstrated that a higher survival rate is needed to generate sufficient profits to cover major restocking costs and a positive payment, or a cost reduction is essential to make up for the loss. On top to these practical constraints, based on the distinctive modest economic situation prevailing for most Chilean coves and hence their limited capacity to pay for stocking material, unless adequate and constant funding is available to support artisanal associations, they are very unlikely to develop mass release programmes. Given the economic (i.e.: high operating costs) and technical (i.e.: low survival rates) limitations conditioning stocking-based management cost-effectiveness and applicability, wide implementation of mass releases as a major approach for management of the red sea urchin fishery is very unlikely to take place in Chile. This study presents a methodology and offers a tool to design, evaluate and optimise coastal management plans for the red sea urchin in a dynamic, interactive, systematic, integrated and flexible way. The optional strategic management plans proposed on this study may not be applied equally to any AMEBR, as they are the outputs arising from a single cove-specific analysis. Still, the complete methodological framework and analysis procedures developed may be applied to run the BSESM and optimise management of a red sea urchin fishery at any other AMEBR case of study.
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Maghaydah, Sofyan. "Utilization of fish processing by-products for nutritional formulation of fish feed." Online version, 2003. http://www.uwstout.edu/lib/thesis/2003/2003maghaydahs.pdf.
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Gheyas, Almas Ara. "Applications of microsatellite markers to genetic management of carps in aquaculture." Thesis, University of Stirling, 2006. http://hdl.handle.net/1893/3577.
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Carp aquaculture in South Asia suffers severely from a lack of genetic management, which has eroded the genetic quality of both captive and wild populations. Use of molecular markers, especially microsatellites, has revolutionized genetic management of hatchery stocks through its ability to detect kinship between individuals and hence in controlling level of inbreeding and loss of genetic diversity. In the present PhD work, microsatellite markers were applied to breeding programmes for silver carp (Hypophthalmichthys molitrix) and common carp (Cyprinus carpio) to study different genetic management aspects and new markers were generated from rohu (Labeo rohita). A set of newly isolated microsatellite markers from silver carp were characterized and two pentaplex PCR reactions were optimized to enable rapid genotyping of large number of individuals at 10 microsatellite loci. The utility of these markers in parentage, sibship and relatedness analysis were assessed by applying them to groups of fish with known relationship. These markers were used for parentage analysis in a breeding programme designed to estimate heritability of harvest weight and length in silver carp. Full- and half-sib families were created in three sets of partly factorial mating and all the families from each set were reared in communal ponds from very early life stages. With ten microsatellites 96.3% of the offspring could be assigned to a single family. Heritability estimates were found to be 0.65 ± 0.13 for weight and 0.50 ± 0.13 for length. High estimates of h2 suggested that this population should respond rapidly to selection for increased harvest size. Microsatellite markers were also applied to monitor the early stages of a mass selection programme in common carp (Cyprinus carpio). The selection was initiated from a base population synthesized from six different stocks. The selected individuals were divided to create two separate lines. The aims of this study were to monitor whether the stocks were represented in the intended proportions in the F1 selected populations, to investigate the relative contribution of families and its impact on effective population size and to identify any loss of molecular genetic variation. Five highly polymorphic microsatellites were used for parentage analysis of the selected fish to track stock and family contribution. Overall, large perturbations were observed in the relative contributions of two major stocks. Family contribution was also highly variable, causing the Ne to drop to below half the census size. A loss of 6.9%-12.2% of microsatellite alleles was observed but loss of heterozygosity was not very prominent. The replicate lines showed significant differences in allelic distribution after the first generation of selection, but not in genotypic distribution. Finally, 52 microsatellite markers were isolated from a partial genomic library of rohu using a selective hybridization protocol. Characterization of these markers resulted in 36 polymorphic loci, which will be useful in future work on conservation and management of both wild and captive rohu populations.
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To, Hong Thi Kim Kinnucan Henry W. "Competiton between domestic and imported farmed fish a demand system analysis /." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Agricultural_Economics_and_Rural_Sociology/Thesis/To_Hong_42.pdf.
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Sotocinal, Samson A. "Design and testing of a natural convection solar fish dryer." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60638.
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A natural convection solar fish dryer consisting of a flat-plate solar collector, drying chamber, and an auxiliary heater was designed, constructed and tested in the Philippines. The dryer is capable of drying 5 kg of fish in 10 hours.Water was first heated in a flat-plate solar collector then through thermosyphon effect, heat and mass was moved to the heat exchanger where heat was transferred to the air. Heated air was allowed to flow through the drying chamber where trays of prepared samples of fish were laid. Pre-drying treatment of fish similar to those used in commercial practice, were used for individual drying experiments in order to permit a general evaluation of the system.
Seven drying experiments using different fish samples were conducted and the data generated was used to determine the efficiency of the system in terms of solar energy utilization. Results indicate that the system function efficiently at a minimal water temperature increase of 10$ sp circ$C, and the dryer operates at a system efficiency of 9 per cent which compares well with the findings of Yu Wai Man (1986) which found that natural convection solar dryers operate in the efficiency range between 7 to 14 per cent.
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Bourillon-Moreno, Luis. "Exclusive fishing zone as a strategy for managing fishery resources by the Seri Indians, Gulf of California, Mexico." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/279963.
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I analyzed the Seri Exclusive Fishing Zone (SEFZ) in the Gulf of California, to assess its efficiency in solving common fisheries management problems related to open access resources. A review of the major historical changes in the socio-cultural context of marine natural resource use in the region showed the SEFZ has allowed the Seri to successfully keep and improve control of access to the Infiernillo Channel, as well as reduce competition with fishers from Bahia Kino in a region with increasing competition for marine resources. However, the SEFZ showed severe limitations that produced conflicts of variable intensity. The most important were lack of clear geographic limits to SEFZ, clear systems to transfer fishing rights, and rights to defend with armed guards the integrity of their marine territory. The role of Seri and Federal Government authorities in conflict creation and resolution and the perception of the outcomes of these conflicts for Seri and Bahia Kino fishers are analyzed on four recent conflict events. Several potential opportunities to promote co-management of fisheries by the federal government and local fisheries management authorities emerged from the SEFZ. However, none of these opportunities, in the form of informal arrangements, succeeded in creating better relationships between Seri and Bahia Kino communities of fishers. I used the jaiba (Callinectes bellicosus) crab fishery inside the SEFZ to assess dynamics of marine resources under Seri common property ownership. I found that inside the SEFZ fishing effort is controlled, the fishing ban is honored, fishing areas are rotated throughout the season, and no-fishing zones are functional. I used data from jaiba buyers, and extensive catch sampling during two fishing seasons, to determine yearly production in Punta Chueca, as well as average daily catch and other descriptive catch statistics. Jaiba is an important resource in the economy of Punta Chueca, and its local management has been facilitated by the SEFZ to produce a fishery that, to date, appears to be sustainable. However, the long-term viability of this fishery inside the SEFZ is vulnerable to outside harvesting patterns and to political and economic influences over which the Seri have no control.
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Bonvini, Erika <1984>. "Development of Innovative Feed Products and Feed Concepts for Marine Species in Aquaculture." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8033/1/Bonvini%20-%20PhD%20thesis.pdf.
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The sustainability challenges of the aquaculture sector will probably be closely linked with continuing interest in ingredients as alternatives to fishmeal for use within aquafeeds. Among the many protein sources available, plant proteins appear to be the most appropriate alternatives. Different aspects on the health implications of using vegetable feed ingredients on the digestive tract, plus possible effects on quality of the fish, are some of the most relevant problems currently confronting the aqua industry.
The need to understand this phenomenon leads to the present thesis, in which the investigation on the feasibility of the inclusion of plant protein in aquafeed was undertaken through a multidisciplinary approach.
The first study highlighted that inclusion of soybean meal in combination with different blends of plant protein maintains optimal growth in 20% fish meal dietary level for the on-growing of European sea bass. Despite fiber is considered as a component that cannot be utilized by most fish, inclusion up to 9.3% has no effects on growth, feed efficiency and digesta transit time in European sea bass. It was encouraging to note that inclusion of high levels of plant protein sources and fiber did not affect health and nutritional status of the animals. When replacing fish meal in aquafeeds, besides the research on alternative ingredients, also the nutritional profile should be considered. In the third study, it was demonstrated that taurine is a required nutrient for juvenile Southern flounder. The fourth study, highlighted that increasing the inclusion of plant ingredients, in substitution of fish meal, had no effects on quality traits of the commercial product.
However, it is not yet an easy or economi¬cally feasible task to reduce the aquaculture dependence from marine feedstuff, the present thesis has contributed to provide some insights on the feasibility of the replacement of fish meal in aquafeed.
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Longo, Stefano B. 1969. "Global sushi: A socio-ecological analysis of the Sicilian bluefin tuna fishery." Thesis, University of Oregon, 2009. http://hdl.handle.net/1794/10230.
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xvii, 330 p. : ill., maps. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.This dissertation is a sociological study of the Sicilian bluefin tuna fishery. It will examine the social and ecological transformation of this fishery during the modern era. This will be analyzed utilizing a sociological framework that draws on theory from environmental sociology. The Sicilian fishery has been exploited for its abundant tuna for over a millennium, providing a major source of protein for Mediterranean civilizations. However, within the last half century there has been exponential expansion of industrialized methods of production and increasing capture efforts. This has culminated in the development of bluefin tuna "ranches," which have become a highly controversial method for supplying global markets. Escalating pressure on the fishery has contributed to a host of environmental and social concerns, including pushing this important fishery to the brink of collapse. Using a combination of primary and secondary source data such as interviews with local fishers and those in the tuna ranching sector, data compiled by international agencies such as the International Commission for the Conservation of Atlantic Tunas (ICCAT) as well as archival data on the Sicilian bluefin tuna fishery, I will employ sociological methods and analyze the recent changes in social life and the environment in Sicilian fishing communities. Subsequently, this project will shed light on the globalized and industrialized nature of the modern agri-food system and lead to a better understanding of its social and environmental impacts.
Committee in charge: Richard York, Chairperson, Sociology; John Foster, Member, Sociology; Yvonne Braun, Member, Sociology; Joseph Fracchia, Outside Member, Honors College
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Webster, Janet Brown. "Identification and characterization of a psychotrophic Clostridium sp. isolated from spoiled pasteurized crabmeat /." This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-07102009-040239/.
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Al-Oufi, Hamed Said. "Social and economic factors influencing the emergence of collective action in a traditional fishery of Oman : an empirical assessment of three coastal fishing towns in south Al-Batinah." Thesis, University of Hull, 1999. http://hydra.hull.ac.uk/resources/hull:3871.
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Overexploitation of many fish stocks underlines the need for more effort directed towards stock management so that the sustainability of resources is assured. To avert the tragic consequences of overfishing in coastal waters, a growing body of theoretical and empirical research provides evidence in support of cooperation among resource users to manage their commons. This study aimed to investigate the factors that contribute to the emergence and evolution of collective action in fishermen's communities to manage their coastal fish resources in South Al-Batinah, Sultanate of Oman. The study emphasises the importance of a collective action approach to fish resource management with examples from three fishing towns.In order to understand why fishermen choose to participate (or not to participate) in local collective action to manage fish resources, the researcher focuses on six main sets of issues that influence fishermen's decisions: economic factors; awareness of resource exploitation problems; institutional rules in use; social identity, group size and heterogeneity among resource users. Social and demographic factors as well as vessel configuration were also considered.Data collection for the study was carried out using three methods: questionnaire, semi-structured interview and observations of fishermen's activities. Statistical reports and other research papers carried out in Oman were also reviewed. The study found that there is a management institution that governs the fishing activities of the fishermen in the study area. Fishermen in the area inherited an indigenous management institution, which was established hundreds of years ago. It was also found that fishermen were very aware of the resource exploitation problems. High awareness of the resource exploitation problems coupled with high interdependence among users might induce them to work collectively to mitigate harm to their long-term welfare.The results of testing a number of hypotheses indicated that among the reasons which may influence collective action, are high economic dependence on the fishery,individuals' social identity as fishermen, awareness of the resources exploitation problems, risk aversion and heterogeneity (differences in objectives and interests).The study findings indicated that individuals using common resources are faced by various "assurance" and "chicken" problems. In both the PD game and the Assurance game, the preferred outcome is mutual cooperation. Whereas the predicted outcome of the former is defection, the latter suggests the possibility that the preferred outcome (i.e., cooperation) will occur, because individuals' decisions in the commons are influenced by a complex set of factors, rather than strictly materialistic self-interest. The analysis presented in this study examined several of those factors for their influence on individual behaviour. The findings of this study strongly suggest that the presence of local management institutions to coordinate the fishermen's activities in the study area is the key factor in avoiding the worst outcome (universal defection). The game structure has been changed from a Prisoner's dilemma to a Privileged game or a game of Chicken where the benefits from cooperation are maximized. It is the role of the institutions to determine how the cost of providing the public goods might be shared among participants.
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Voller, Samuel W. "The impacts of wheat gluten products and short-chain fructooligosaccharides on the health and production of juvenile rainbow trout (Oncorhynchus mykiss)." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9826.
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Through the implementation of in vivo feeding trials, the efficacy of three wheat gluten (WG) products, vital (Amytex®), hydrolysed (Merripro®) and soluble hydrolysed (Solpro®) wheat gluten as replacement of soy protein concentrate, and scFOS prebiotic (Profeed®) supplementation were analysed to assess their impacts on intestinal health and production of juvenile rainbow trout. Microbial community analysis in experiment one revealed a degree of diet based modulation with 7.5% and 15% inclusions of wheat gluten (WG) products. Bacterial species diversity was significantly reduced with 15% hydrolysed wheat gluten (HWG) inclusion compared to the plant protein control and 15% vital wheat gluten (VWG) treatments, with sequenced OTUs dominated by the phylum Firmicutes and possible promotion of probiotic species. No detrimental effects were observed on intestinal morphology. These findings led onto a longer duration feed trial with a more holistic, higher resolution approach. Experiment two revealed modulation of the allochthonous intestinal microbiota, with increased proportions of Enterococcus and Weissella in the 10% and 20% VWG treatments. Bacillus and Leuconostoc relative abundances were significantly increased with 10% HWG and soluble hydrolysed (Sol) wheat gluten inclusions. HSP 70 transcripts were significantly down-regulated in all WG treatments compared to the basal soy protein concentrate treatment (SPC) and increased intraepithelial leukocyte counts were observed with 10% VWG inclusion. Growth performance was unaffected by 10% dietary inclusions of WG, however, FCR’s were significantly improved in the 20% VWG treatment compared to the 10% HWG and Soluble treatments. This led to the investigation of increased inclusion levels of WG products in experiment three. All WG treatments in experiment three yielded significantly improved growth performance. Somatic indices were significantly increased with 30% blended WG inclusion compared to the SPC treatment. Modulation of allochthonous intestinal microbiota was observed to a lower degree than the previous experiments, with a dose response observed with increasing blended WG inclusion. In the final experiment two basal diets (SPC and 20% Blended) and two scFOS supplemented diets (SPC + FOS and 20% Blended + FOS) were investigated for the effect on growth performance, gut health and allochthonous microbial population. Growth performance was unaffected, however, modulation of the allochthonous microbial population was observed with an apparent synergistic effect of scFOS supplementation in WG diets. This synergistic trend was also observed in the transcription level expression of immune relevant genes. 20% WG inclusion with additional scFOS supplementation observed significant down regulation of the pro-inflammatory cytokine TNF-α, as well as HSP 70, CASP 3 and Glute ST compared to the 20% Blend treatment. The present research demonstrates dietary inclusions of WG products, solely or blended, at the expense of soy protein concentrate to modulate the allochthonous microbial population, potentially promoting probiotic species, whilst reducing the levels of intestinal stress in juvenile rainbow trout. Supplementation of the prebiotic scFOS modulated the microbial populations, enhancing the proportion of potential probiotic species, and combined with WG inclusions, reduce intestinal and oxidative stress and inflammation biomarkers, with no observed deleterious effects.
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Al-Omirah, Husam F. "Proteolytic degradation products as indicators of quality in meat and fish." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27268.
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Assessment of freshness and quality of meat and fish is a major activity of both food regulatory agencies and the food industry. Various methods are used for measuring fish and meat quality, each with its particular advantages and limitations. However, methods based on monitoring the products of proteolysis have received relatively little attention. The objective of the present study was to identify specific protein and peptide products of proteolysis as indicators of freshness and quality during chilled storage of fresh fish and meat.Samples of meat and fish were subjected to chilled storage; at intervals of 0, 2, 4, 8, 12 and 16 days, samples were subjected to protein and peptide extraction, and separation of individual sarcoplasmic and myofibrillar proteins by SDS and native electrophoresis. These extracted proteins along with acid soluble nitrogen (ASN) were separated by RP-HPLC, fractions were collected and identified by electrospray ionization mass spectrometry (ESI-MS).
RP-HPLC separated at least thirty fractions from the ASN extract of fresh fish. ESI-MS revealed the presence of at least twenty-five polypeptides with molecular weights (MW) ranging from 2 to 32 kDa. The relative area % of the polypeptides with MW 32.8 kDa and 42.8 kDa decreased during the storage while polypeptides of MW of 10.9 kDa and 16.7 kDa increased during storage. Changes in polypeptides of MW 12, 34.2 and 42.8 kDa was also observed. The sarcoplasmic protein extracted from ground and whole meat contained at least 12 polypeptides with MW ranging from 11 to 42 kDa. The relative area % of polypeptide of MW of 35.7 kDa decreased during storage. The results suggest that changes in proteins and polypeptides of MW 10.9, 12, 16.7, 32.8, 34.2 and 42.88 kDa in fish and 35.7 kDa in meat could serve as indicators of spoilage.
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Webster, Janet B. "Identification and characterization of a psychotrophic Clostridium sp. isolated from spoiled pasteurized crabmeat." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/43608.
Full textAbstract:
A number of crab processors in the Maryland and Virginia region experienced an abnormally high incidence of spoilage in their pasteurized product in the fall of 1989. The spoilage was only seen in cans that were processed either shortly before or after hurricane Hugo and the majority of spoilage occurred in machine picked meat only. All processors pasteurized the meat at least to an Fi~5 of 32 minutes, which is the minimum National Blue Crab Industry Association (NBCIA) recommendation.
Spoiled pasteurized crabmeat, processed in 1989 and 1990, were analyzed for their microbial content. Several cans that had spoiled in 1972 were also analyzed for microbial content Isolated organisms were tested for heat tolerance, and those organisms able to survive an F11~5 of 32 minutes or longer were identified. Can seams were evaluated to determine if the spoilage was due to post processing contamination. Approximate D-values were determined for the heat tolerant organisms.
A psychrotrophic Clostridium sp. was found in all cans tested from a Maryland processor, Processor B. This processor only had spoilage in machine picked meat pasteurized after hurricane Hugo. Spoilage was seen in cans which had received a F 16/185 of 80 to 100 minutes. Spores from this organism had an approximate D-value of 6.5 minutes at 85 C in brain heart infusion broth (BHI). Cans from Processor B did not show any seam defects, and it was concluded that spoilage was due to the survival of spores, during pasteurization, from the Clostridium sp. that were able to outgrow at the temperature at which crabmeat is stored commercially.
A Bacillus sp., possibly Bacillus pasteuranii, was found in one can from Processor B. Spores from this organism have an approximate D-value of 26.5 minutes in BHI broth at 85 C. This organism is unable to grow at refrigeration temperatures and it is not felt to have caused spoilage in the crabmeat.
The Clostridium sp. found in cans from Processor B, pasteurized in 1989 and 1990, was also found in a can of jumbo lump meat from Processor D, processed in 1989, and a can of claw meat from Processor E, pasteurized around 1972.
Cans from Processor A, who saw small amounts of spoilage before hurricane Hugo and in some hand- picked meat as well as machine piced meat had can seam measurements which did not meet specifications. It was concluded that spoilage from this processor was due to post-processing contamination.
Crab processors must be aware that spores, from organisms that are able to outgrow at refrigeration temperatures, are able to survive pasteurization. The Clostridium sp. isolated in this study is one example. Processors will need to make sure their product is receiving sufficient heat to kill all spores of these organisms, while still maintaining a product with good sensory characteristics. It appears, from this study, that crab processors may want to increase the F-value that a lot of crabmeat receives after major storms, since the Clostridium sp. seemed to show up after hurricanes. Finally, crab processors need to be stringent in their sanitation and cleanliness so as to minimize the numbers of these types of organisms in their product.Master of Science
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Dauphin, Laurie. "Enhancing value of lobster waste by enzymatic methods." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60541.
Full textAbstract:
In processing lobster, approximately 70% of the body weight is discarded as waste. The solid waste consists of shell, viscera and a small amount of meat. Lobster waste is an excellent source of protein (26.6%) crude fat (2.7%) and pigment (98 $ mu$g/g) on a dry weight basis which could be processed into a stable complex known as carotenoprotein.Procedures for extraction of carotenoprotein from lobster waste have been developed, along with investigation of its distinctive physicochemical properties. The main factors were: demineralization agents (EDTA, HCl or heat) and precipitation agents ((NH$ sb4$)$ sb2$SO$ sb4$ or HCl). Lobster carotenoprotein recovered under different extraction procedures showed significant differences in terms of quantity and quality of the product recovered. However the procedures did not appear to affect the physical properties and amino acid profiles of carotenoprotein.
Optimal recovery involved treatment with EDTA as demineralization agent and precipitation with (NH$ sb4$)$ sb2$SO$ sb4$. Proximate and amino acid analyses indicated the potential of the recovered lyophilized protein as feed ingredient for cultured salmonids.
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Tu, Ya. "Recovery, drying and characterization of carotenoproteins from industrial lobster waste." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59936.
Full textAbstract:
Lobster waste (including the head and hard carapace, viscera, mandibles and gills) contains approximately 98 $ mu$g/g total astaxanthin, 23% protein, 20% chitin, 34% ash, and 2.2% crude fat on dry weight basis. Carotenoprotein, amounting to 16% of the dry matter was effectively recovered from lobster waste by a trypsin aided process. Air-dried carotenoproteins were enriched in protein by about 108-115%, in crude fat by 540-594% and in carotenoid pigment by about 147-329% as compared with the waste material. Furthermore, the ash and chitin levels in the products were considerably lower than those of the raw material.Drying characteristics of carotenoprotein was evaluated in a modified air-drier using air temperature (45$ sp circ$C, 55$ sp circ$C or 65$ sp circ$C) and relative humidity (5% and 15%) as main factors. The study indicated that higher temperatures achieved faster drying rates of the product but adversely affected its nutritional composition and/or quality. The proximate compositions of carotenoprotein dried at 45$ sp circ$C and relative humidity of 5% or 15% were comparable with that obtained by freeze drying.
Thus, the process achieved a substantial reduction in the levels of anti-nutrients associated with lobster waste (i.e., ash and chitin) while elevating the levels of carotenoid pigments and essential nutrients such as protein and fat in the recovered product. These characteristics of the tray-dried carotenoprotein suggest that it could be used as an inexpensive source of pigment and protein in diets of cultured salmonid species.
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Onodenalore, Akhile Collins. "Value-added functional protein products and endogenous antioxidants from aquatic species." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0018/NQ54850.pdf.
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Barua, Mala A. "Determination of decomposition rates in selected mid-Atlantic fish species stored under iced and super-chilling temperatures." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08222009-040231/.
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McAuley, Rory B. "Investigation of the fishery biology and population status of the sandbar shark (Carcharhinus plumbeus, Nardo 1827) in Western Australian waters." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2007. https://ro.ecu.edu.au/theses/280.
Full textAbstract:
The sandbar shark (Carchrarhinus plumbeus) is a commercially important shark species to fisheries around the world but is known to be highly susceptible to over·fishing. During the late 1990s, changes in the targeting practices of Western Australian demersal gillnet fishing vessels, and an expansion of targeted demersal longlining in the north of the State, caused a rapid escalation in C. plumbeus catches. This study therefore aimed to collect the biological and fishery data necessary to assess the impacts of increasing exploitation of the species and to develop biologically appropriate techniques for assessing the sustainability of these fishery developments.
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Glass, Jessica Rose. "Spatiotemporal variation of benthic communities on weathervane scallop (Patinopecten caurinus) beds with socioeconomic considerations of the commercial fishery off the coast of Alaska." Thesis, University of Alaska Fairbanks, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1566803.
Full textAbstract:
Weathervane scallops (Patinopecten caurinus [Gould, 1850]) off Alaska are commercially harvested in areas that contain commercially important groundfish and crabs. Using observer bycatch data collected during 1996-2012, we analyzed spatial and temporal patterns in community composition on weathervane scallop beds and explored whether observed patterns related to environmental variables (sediment, depth, bottom water temperature, and freshwater discharge) and anthropogenic variables (trawling and dredging effort). Significant (P<0.05) differences in community structure were observed at the scale of state fishery registration districts, as well as among individual scallop beds. Spatial differences were most strongly correlated with sediment, depth, and dredging effort. Sequential changes over time were also detected, as was a split between 1996-1999 and 2000-2012. Temporal changes were weakly yet significantly correlated with freshwater discharge and dredging effort. We also conducted a socioeconomic assessment of the commercial weathervane scallop fishery, structured within the framework of a SWOT (strengths, weaknesses, opportunities, threats) analysis. Specifically, we focused on five categories: social, technological, economic, environmental, and regulatory. Whereas the data-poor status of the stock appears to be the fishery's biggest weakness, the largest strengths are conservative management, industry self-regulation, and the fishery's small footprint. Impending threats include stock declines, effects of dredging, and changes in the structure of the fishery. These analyses provide a baseline of benthic community composition on weathervane scallop beds, as well as socioeconomic information to contribute to the environmental, economic, and social sustainability of the Alaska scallop fishery.