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 63 for “"Anchovy"”.
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Abundance and mortality of anchovy eggs caused by cannibalism and intraguild predation, and the potential effect on anchovy recruitment and clupeoid fluctuations
This thesis is structured in the form of five main chapters, each written in the form of an independent paper and supported by a general conclusion and one previously published paper on the same general theme. The central theme is the dynamics, ecology and evolution of intraspecific and intraguild …
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Egg cannibalism by anchovy in the Southern Benguela Current Region
Samples of adult anchovy and plankton were collected on Sea Fisheries Research Institute R.S. Africana 1984-1985 anchovy spawner biomass estimation cruises. A total of 40 sets of anchovy samples of 30 fish each and 40 plankton samples were taken roughly at the same time within an area of intensive …
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Estimate of size and interaction of the South African anchovy and pilchard populations
The size of the South African anchovy and pilchard population was estimated using Virtual Population Analysis (Gulland 1965). These estimates were used to test classical stock recruit models as well as to investigate possible stock interactions. The population biomass of the pilchard indicated a …
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Ecology of the migration and distribution of the anchovy Engraulis capensis off Namibia
… and migration of the adult and recruit shoals of anchovy Engraulis capensis off Namibia and the environmental factors most important to such distributions and migrations. It also examines anchovy feeding patterns. The distributions of anchovy shoals in summer months were recorded during extensive, …
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Inter-Annual to Inter-Decadal Variability of Upwelling and Anchovy Population off Northern Chile
… how these changes may affect the upwelling and anchovy variability. Data used in this thesis includes time series of wind, sea level, sea surface temperature, and atmospheric pressure at coastal stations, from 1960 to 2003, and oceanographic and acoustic cruises for the period 1993–2003. The …
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Hatchdate distributions and growth rates of anchovy (Engraulis encrasicolus) in the Southern Benguela ecosystem
Larval and juvenile Cape anchovy (Engraulis encrasicolus) of the particularly strong 1999/2000 year-class were collected during two consecutive surveys in March and May 2000 in the southern Bengueia region off South Africa. Otoliths from sub-samples were examined to calculate hatchdate …
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Effects of global climate change on the recruitment of Anchovy in the Southern Benguela upwelling system
… may impact on the recruitment of the Cape anchovy, Engraulis capensis. A general circulation model (NCAR Climate System Model) is used to compare a future simulation under double C02 conditions with a simulation of the present day wind regime. Climate change effects on anchovy in the other …
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Evaluating the implementation efficacy of an ecosystem approach to fisheries in the South African anchovy fishery
… approach to fisheries in the South African anchovy fishery. South Africa has agreed to implement an ecosystem approach to fisheries (EAF) management. The EAF management comprises of three dimensions; ecological well-being, human well-being and ability to achieve. The focus for this study was …
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Modelling the oceanographic transport of young Cape anchovy Engraulis capensis by advective processes off South Africa
… transport by currents above the thermocline for anchovy recruitment off South Africa. Simulation studies indicate that mean year-class strength of Cape anchovy is relatively robust to altered advective processes off South Africa. This occurs despite the fact that changed flow alters the …
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An assessment of the reliability of fossil pilchard and anchovy scales as fish population indicators off Namibia
… from the pilchard, Sardinops ocellata, and the anchovy, Engraulis capensis, is presented. Both species show an unexpected range of scale types. The classifications reduce errors in distinguishing between the scales of the two species to ±2,5%. Scale loss from these fish is quantified under …
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The development and implementation of a joint management procedure for the South African pilchard and anchovy resources
Pilchard and anchovy are the main targets of the pelagic fishery, South Africa's second most valuable fishery in monetary terms, but producing the highest annual yield in terms of landed mass. It is the most dynamic of South Africa's major commercial fisheries, because the species it targets are …
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Egg and larval ecology of anchovy (Engraulis capensis) and sardine (Sardinops sagax) in the Southern Benguela ecosystem
… changes in the abundance and distribution of anchovy and sardine eggs and larvae in the southern Benguela ecosystem were investigated during 14 cruises over 2 consecutive summer upwelling seasons as part of the South African Sardine and Anchovy Recruitment programme (SA-SARP). Cruises were …
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Predicting water quality effects on bay anchovy (Anchoa mitchilli) growth and production in Chesapeake Bay: linking water quality and individual-based fish models
… I combined two water quality models with bay anchovy models (Anchoa mitchilli) to examine the effects of changes in nutrient loadings on anchovy survival and growth. An individual-based predation model was statically linked to Patuxent River watershed land-use and water quality models, and …
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The uptake, distribution, and depuration of ¹⁴C benzene in Northern anchovy (Engraulis mordax) and Striped bass (Morone saxatilis)
… in two species of marine fish, Nature northern anchovy (Engraulis mordax) and juvenile striped bass (Horone saxatilis) were exposed to sub-lethal concentrations of <sup>14</sup>c benzene for 48 hours. Residues in tissues exhibiting a high lipid content (non-metabolic pathway) or representing …
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Comparing in situ and satellite temperature data on the Agulhas Bank to understand changes in anchovy (Engroulis encrasicolus) distribution
… Agulhas Bank and the relative distribution of anchovy (Engraulis encrasicolus) spawner biomass east of Cape Agulhas. However, other studies have shown that nearshore satellite data may not be as accurate as originally believed. Using the relationship observed in the aforementioned study as a …
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Modelling dominance shifts of anchovy and sardine with a frame-based approach : sensitivity to the underlying sardine population dynamics
It has been shown that sardine and anchovy populations in the southern Benguela have alternated dominance during the past 50 years, and a frame based model that explores the usefulness of frames within a marine ecosystem by modelling sardine/anchovy dominance shifts in the southern Benguela has …
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Characterizing and comparing the spawning habitats of sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus) in the northern Benguela region
Spawning habitats of sardine and anchovy in eastern boundary systems are characterized in an attempt to understand the fluctuations observed in their abundance. These species have developed mechanisms that enable them to survive in these turbulent conditions. Spawning habitats were characterized by …
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Variability of copepod abundance and growth in the southern Benguela upwelling system and implications for the spawning of the Cape anchovy
In the southern Benguela upwelling system, anchovy spawn serially between September and February each year. It has been suggested that this energy-intensive reproductive strategy requires continual ingestion of copepods, which dominate the diet of anchovy at this time. This thesis investigates the …
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Characterizing and comparing the spawning habitats of anchovy (Engraulis capensis) and sardine (Sardinops sagax) in the Southern Benguela upwelling ecosystem
The spawmng habitats of anchovy (Engraulis capensis) and sardine (Sardinops sagax) in the southern Benguela upwelling ecosystem were characterized by comparing the data on abundance and distribution of eggs of the two species with environmental variables. Data were collected from two different …
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