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 17 of 17 for “"Pelagic fishes"”.
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Multidisciplinary investigation into stock structure of small pelagic fishes in southern Africa
Three abundant small pelagic fish species co-occur in the Benguela upwelling ecosystem off southern Africa: sardine (Sardinops sagax), anchovy (Engraulis encrasicolus) and round herring (Etrumeus whiteheadi). It is hypothesised that populations of these species have a complex structure that …
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Movements and oceanographic associations of large pelagic fishes in the North Atlantic Ocean
Highly migratory marine fishes support valuable commercial fisheries worldwide. Yet, many target species have proven difficult to study due to long-distance migrations and regular deep diving. Despite the dominance of oceanographic features, such as fronts and eddies, in the open ocean, the …
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Movements and oceanographic associations of large pelagic fishes in the North Atlantic Ocean
Highly migratory marine fishes support valuable commercial fisheries worldwide. Yet, many target species have proven difficult to study due to long-distance migrations and regular deep diving. Despite the dominance of oceanographic features, such as fronts and eddies, in the open ocean, the …
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Developing dynamic energy budget (DEB) models for small pelagic fishes in the Southern Benguela
… ecosystems. Differential responses of small pelagic fish species to environmental factors help in understanding the variable population dynamics of these species and can help predict the impacts of climate change.
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Movement and trophic ecology of large pelagic fishes connecting surface waters with the Ocean’s Twilight Zone
… 1000 meters. Recent work in the twilight (or mesopelagic) zone has revealed unexpected biomass and diversity that may not only challenge scientific understanding of ocean systems but also provide new and largely untapped resources for fisheries harvest. The extent to which commercially valuable, …
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Seasonal and spatial variability of pelagic fishes in relation to environmental variability in St Helena Bay
… are significant to early life history of small pelagic fish. Environmental, acoustic and zooplankton data have been collected along the SHBML to obtain information on ocean environment, pelagic fish abundance and also zooplankton abundance. This study used an interdisciplinary approach, …
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Movement and Trophic Ecology of Large Pelagic Fishes Connecting Surface Waters with the Ocean's Twilight Zone
… 1000 meters. Recent work in the twilight (or mesopelagic) zone has revealed unexpected biomass and diversity that may not only challenge scientific understanding of ocean systems but also provide new and largely untapped resources for fisheries harvest. The extent to which commercially valuable, …
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Investigating the trophic ecologies of early life stages of small pelagic fishes in the Benguela upwelling ecosystem
… Africa, harbours large biomasses of three small pelagic fishes; anchovy Engraulis encrasicolus, sardine Sardinops sagax and west coast round herring Etrumeus whiteheadi. Despite fisheries management interventions, stocks of sardine have been low for the past decade following consecutive years of …
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Tracking diet and movement of Atlantic bluefin tuna (Thunnus thynnus) using carbon and nitrogen stable isotopes
… Thunnus thynnus) are important top predators in pelagic ecosystems. Understanding their diet and movements is necessary for proper management, but existing methods are costly and logistically challenging. Naturally occurring stable isotopes have been used to study diet and movement in many …
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Trophic Ecology of Mesopelagic Fish Larvae and Juveniles in the Northern Gulf of Mexico
<p>The deep-pelagic environment encompasses ocean waters below 200 m depth, and comprises 90% of the volume of the Gulf of Mexico. Deep-pelagic fishes are important prey for many oceanic consumers, but relatively little is known about their early life history, including larval fish trophic ecology. …
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Environmental drivers of the abundance and distribution of forage fishes on the Northeast US shelf, with a particular emphasis on northern sand lance
Small pelagic fishes, also termed forage fishes, represent a critical link between secondary production and myriad top predators in marine ecosystems, including the Northeast US shelf. In this dissertation, I analyze the drivers of forage fish distribution throughout the Northeast US shelf and the …
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Environmental drivers of the abundance and distribution of forage fishes on the Northeast US shelf, with a particular emphasis on northern sand lance
Small pelagic fishes, also termed forage fishes, represent a critical link between secondary production and myriad top predators in marine ecosystems, including the Northeast US shelf. In this dissertation, I analyze the drivers of forage fish distribution throughout the Northeast US shelf and the …
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The Distribution and Abundance of Bluntnose Flyingfish (Prognichthys occidentalis) Across the Gulf of Mexico
Flyingfishes are an essential component of pelagic food webs, serving as both predator and prey. Many pelagic fishes (billfishes, dolphinfishes, and tunas) consume large quantities of flyingfish, and several studies have documented their importance as prey for apex predators residing in coastal and …
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Population structure, biochemical adaptation and systematics in temperate marine fishes of the genera Arripis and Chrysophrys (Pisces: Perciformes)
… amount and distribution of genetic variation in fishes of the temperate percoid genera Arripis and Chrysophrys. Available biological and life history data have been reviewed, and indicate that Arripis species are mobile, migratory, pelagic fishes, with planktonic larvae and a comparatively short …
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Population structure, biochemical adaptation and systematics in temperate marine fishes of the genera Arripis and Chrysophrys (Pisces: Perciformes)
… amount and distribution of genetic variation in fishes of the temperate percoid genera Arripis and Chrysophrys. Available biological and life history data have been reviewed, and indicate that Arripis species are mobile, migratory, pelagic fishes, with planktonic larvae and a comparatively short …
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Bayesian hierarchical approaches to analyze spatiotemporal dynamics of fish populations
… Blueback Herring (A. aestivalis), are anadromous pelagic fishes that spend most of the annual cycle at sea and enter coastal rivers in spring to spawn. Alosa fisheries were once one of the most valuable along the Atlantic coast, but have declined in recent decades due to pollution, overfishing and …
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Using seasonal mass-balanced models of the Algoa Bay ecosystem to investigate African penguin and small pelagic fish interactions
… to investigate the interaction between the small pelagic fish and penguin population, mass-balanced trophic models of the Algoa Bay ecosystem were constructed using the software Ecopath with Ecosim. Input parameters were derived from data compiled from published literature and survey data …