Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"stock structure"”.
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Multidisciplinary investigation into stock structure of small pelagic fishes in southern Africa
… that populations of these species have a complex structure that reflects the complexity of their varying habitats. On the basis of the locality and timing of spawning, and morphological, meristic and parasite studies, it has been proposed that there are separate stocks of sardine in South African …
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Humpback whales, rock lobsters and mathematics : exploration of assessment models incorporating stock-structure
This thesis presents four marine resource assessments; three concern the Southern Hemisphere (SH) humpback whale (Megaptera novaeangliae) and one the South African east coast rock lobster Palinurus delagoae. It also sets out the statistical background to the methodology employed in the assessments, …
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Genetic stock structure and estimation of abundance of swordfish (Xiphias gladius) in South Africa
… at 20°E. Consequently, all tunas and billfish stocks with the exception of the southern bluefin tuna (Thunnus maccoyii), are artificially divided into Atlantic and Indian Ocean stocks along this boundary, regardless of their true stock structure and distribution. Since questions remain about …
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Genetic evaluation of walleye (Stizostedion vitreum vitreum) stock structure and recruitment in Claytor Lake, Virginia
Walleyes from several geographic areas have been stocked in Claytor Lake since 1940. Fish presently in the reservoir may have originated from the stocking of Kansas, Nebraska, or Pennsylvania walleyes, or may possibly be descended from a native New River walleye strain. Recent stockings (1974, …
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Using otolith shape and DNA to identify the stock structure of the spotted wolffish (Anarhichas minor) around Iceland
Proper stock identification is a cornerstone of sustainable fisheries management. The spotted wolffish is overfished in Icelandic waters, primarily due to its capture as bycatch in other fisheries. To determine whether one or more stocks of spotted wolffish (Anarhichas minor) inhabit the waters of …
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Estimates of length-at-50% maturity of two South African demersal species: Monkfish, Lophius vomerinus, and Kingklip, Genypterus capensis
… is a fundamental biological parameter to monitor stock-health, spawning potential and improve fishery management. This research was focused on computing L50 estimates for both species, separated by sex and coast. As the stock structure for both species is still under debate, reproductive …
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Un approccio multidisciplinare per l’identificazione dello stock del nasello (Merluccius merluccius, Linnaeus 1758) nei mari sardi
The “stock” concept is fundamental to fisheries management. To manage a fishery responsibly it is important to understand its stock structure and how fishing effort and mortality are distributed (Begg e Waldman, 1999). The failure to comply the true stock structure and the ineffective fisheries …
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A survey of the metazoan parasite assemblage of snoek, Thyrsites atun (Euphrasen, 1791), off South Africa with an assessment of host-parasite relationships and potential biological tags
… potential of parasites as biological tags for stock structure studies. Examination of 210 snoek (FL 411 - 1040 mm) revealed them to be host to 16 parasite taxa. These included 9 new host records (Tentacularia coryphaenae, Caligus coryphaenae, Caligus dakari, Corynosoma australe, Nothobomolochus …
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The population dynamics of shortnose gar in the Illinois River to inform management of an emerging recreational fishery
… assessments to estimate the relative abundance, stock structure and vital rates of Shortnose Gar (Lepisosteus platostomus) in the lower Illinois River. The findings indicate that Shortnose Gar exhibit slow growth rates, large body size, variable recruitment and long life spans characteristic of a …
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Inventory optimization in high volume aerospace supply chains
… This thesis outlines a system for optimal safety stock management in high volume aerospace supply chains. Given such supply chain parameters as component inventory values, procurement and manufacturing lead times, demand distributions, and bills of material, the ideal safety stock locations and …
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Influence of Diet and Environmental Variation on Physiological Responses of Juvenile Pallid Sturgeon (Scaphirhynchus albus)
… to mitigate the decline of pallid sturgeon. Stocking of hatchery raised pallid sturgeon has been an important short-term recovery effort for the prevention of local extirpations. Thus, producing healthy pallid sturgeon, maximizing genetic diversity, and preserving locally adapted populations …
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Development of a Genetic Monitoring Program for Stock Enhancement of Mississippi Spotted Seatrout (<i>Cynoscion nebulosus</i>)
… exploited in the northcentral Gulf of Mexico. A stock enhancement research program was initiated in 2004 to develop methods to culture juveniles and release them in natural habitats to increase recruitment in the fishery. The goal of this study was to initiate a genetic monitoring program for …
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Conservation Genetics of Gar (Atractosteus spp.)
… this task a challenge. Here, the population structure of <em>A. spatula</em> was examined on both a fine-scale (within 10 km) and large scale (across its entire range). With an understanding of the stock structure of this species, management efforts can be tailored to best preserve the …
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A Population Genomic Study of Mutton Snapper (Lutjanus analis) Throughout Florida and the Caribbean
… pelagic larval phase. Information on genetic stock structure is critical to design management units for mutton snapper fisheries. Previous genetic studies did not detect significant structuring, but the surveys only included 8-16 genetic markers and limited geographic sampling. In this study, …
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In Support of a Rationally Managed Fishery: Age and Growth in Patagonian Toothfish (<i>Dissostichus eleginoides</i>)
… southern South America and the Southern Ocean. Stock structure, critical to good fisheries management, can be inferred from growth differences between areas, but available growth data are compromised by inconsistencies in age estimation methods, sampling and sample sizes, and techniques used to …
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Parasites of Kunene horse mackerel Trachurus trecae (Smith-Vaniz, 1986) with a comparison of parasites of Cape horse mackerel T. capensis (Castelnau, 1861) in the northern Benguela
… or biotag for discriminating between different stocks of T. trecae and between T. trecae and T. capensis in the northern Benguela. Due to the lack of literature regarding the life history of T. trecae it is difficult to assess why there are sex effects on parasites infecting this species, as …
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Genetic Characterization of Intermixed Walleye Stocks in Claytor Lake and the Upper New River, Virginia
… a number of genetically different walleye stocks have been stocked in Claytor Lake, Virginia. The increasing importance of the walleye fishery led to interest in clarifying key unknowns regarding the biology of the New River walleye stock. A radio telemetry study and genetic evaluation of …
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Dynamic scheduling of manufacturing systems with setups and random disruptions
… its maximum production rate until a fixed base stock level is reached. Then, before switching setups, the policy might produce the current part type at its demand rate for some additional time. When selecting changeovers, the HZP implements two types of decision rules. If the difference between …
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A mid-Atlantic study of the movement patterns and population distribution of the American horseshoe crab (Limulus polyphemus)
In conjunction with Cambrex, a biomedical company that utilizes horseshoe crabs for the production of Limulus Amoebocyte Lysate (LAL), a study was conducted to investigate movement patterns and population distributions of horseshoe crabs to increase understanding of mid-Atlantic horseshoe crab …
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Fishery, population dynamics and stock assessment of geelbek (Atractoscion aequidens), a commercially important migrant fish species off the coast of South Africa
… are comprised of immature fish, making the stock vulnerable to growth overfishing. Adults (>5 years) migrate seasonally to spawn off KwaZulu-Natal and congregate in offshore shoals at night. These spawning aggregations allow fishermen to catch large numbers of fish, making geelbek also …