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 29 for “"year class strength"”.
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Smallmouth bass mortality during parental care: implications for year-class strength
I tested hypotheses that daily mortality rates (DMR) of smallmouth bass offspring were influenced by life stage, density and growth, parental male attributes, fungus infection (egg stage), and predation during parental care in the North Anna River, Virginia. In 1994, stream discharge was relatively …
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Indexing Walleye Recruitment in Eastern South Dakota Natural Lakes
… in eastern South Dakota. For nearly 20 years, fall night electrofishing has been used to monitor age-0 Walleye population parameters, and index future year-class strength in select waters but with limited evaluation. Additionally, knowledge of recruitment patterns and factors that …
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Modelling the oceanographic transport of young Cape anchovy Engraulis capensis by advective processes off South Africa
… 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 likelihood of offshore advection and hence losses of anchovy from the system. Two …
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Sauger Population Ecology in Three Missouri River Mainstem Reservoirs
… I genetically identified and determined relative year-class strength for 1,454 sauger, walleye, and naturally produced hybrids from three Missouri River reservoirs (Lakes Sharpe, Francis Case, and Lewis and Clark) to examine patterns of hybridization, and to quantify factors influencing year class …
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Bluegill Reproductive Biology and Population Dynamics in Four South Dakota Impoundments
… to those from sagittal otoliths over the first 5 years of bluegill lifespan. However, scale ages were consistently underestimated for older bluegills in comparison with the otoliths (a validated aging structure). When accurate age-structure assessment or mortality rate determination is required, I …
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Lake Sturgeon Biology in Rainy Lake, Minnesota and Ontario
… Lake discharge, and Rainy Lake water levels to year-class strength of lake sturgeon in Rainy Lake. Results of gill net efforts throughout the study indicate a substantial population of lake sturgeon in Rainy Lake. Based on body condition and growth, lake sturgeon in Rainy Lake were relatively …
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Analysis of Cisco (Coregonus artedi) Populations in Eastern Lake Ontario
… to life-history traits, and fluctuations in year-class strength. In order to identify whether fisheries-induced change has occurred in this population, I compared the size-at-age and maturation of the ELO population both before [1926-1928] and after [1992-2016] the collapse of the fishery. …
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Yellow perch in Lake Michigan: investigating size-selective mortality and alternative estimators of age
… of multiple variables is likely responsible for year-class strength and the prevalence of any individual factor may vary from year to year. Within Lake Michigan, yellow perch, Perca flavescens, have experienced widespread recruitment failure persisting from the early 1990s to the present. As one …
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The efficacy of back calculation methods for determining length at age data and the use of such data to determine growth standards, national growth patterns and recruitment dynamics of roach (Rutilus rutilus (L.)), dace (Leuciscus leuciscus (L.)) and chub (Leuciscus cephalus (L.)) in UK rivers
… the high latitudes and easterly longitudes.The year class strength of fish is an important index in the management of freshwater fisheries (Cowx and Frear 2004) with early developmental stages representing a crucial period in cyprinid fishes where variations in mortality during this period are …
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Recruitment of Bluegill and Yellow Perch in Nebraska Sandhills Lakes: Integrating Multiple Life Stages
… on four topics, 1) the effect of climate on year-class strength of multiple populations broadly across a series of Nebraska Sandhills lakes, 2) larval prey selection and match- mismatch regulation of recruitment, 3) age-0 dynamics and the potential effect of abiotic and biotic variables on …
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Exploring the ecological differences between black crappie and white crappie
… crappie populations. I found that black crappie year-class strength was positively related to gizzard shad catch per unit effort (CPUE) and temperature, whereas white crappie year-class strength was negatively related to common carp CPUE and largemouth bass CPUE. First-year growth of both species …
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Assessment of Walleye, Sauger, and Black Bass Populations in Lewis and Clark Lake, South Dakota
The relationships between year-class strength of walleye Stizostedion vitreum and sauger s. canadense, as indexed by age-0 seine catch per unit effort (CPUE) , and environmental variables were assessed in Lewis and Clark Lake, South Dakota, from 1985 through 1994. Significant (P≤0. 10) correlations …
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Lake Sturgeon (Acipenser fulvescens) Population Attributes, Reproductive Structure, and Distribution in Namakan Reservoir, Minnesota and Ontario
… sturgeon in the Namakan Reservoir. I evaluated year class strength and reproductive structure of lake sturgeon collected in the U.S. and Canadian waters of Namakan Reservoir. Reproductive structure of lake sturgeon was assessed during spring 2008 and 2009 using plasma testosterone and …
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Modeling the processes affecting larval haddock (Melanogrammus aeglefinus) survival on Georges Bank
… single most important natural event controlling year-class strength and biomass in fish populations. As evident in Georges Bank haddock, Melanogrammus aeglefinus, there is a strong relationship between recruitment success and processes occurring during the planktonic larval stage. Spatially …
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Dynamics of the atlantic salmon (Salmo salar L.) population of the River Foyle, Ireland
… of population size (redd counts) using a 49 year dataset. The evidence suggests that year class strength is the principal modulator of variation in commercial catches, sport angling catches and spawning escapement. Chapter 3 examines the role of density-dependence in the Foyle salmon …
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Predicting the ecological consequences of river management for a riverine cyprinid fish.
… damaging to roach recruitment, subsequent year-class strength and therefore, populations in subsequent years. Recommendations for more sympathetic management schemes are provided. The modelling framework described here can be used to produce robust predictions of roach population patterns …
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Role of Parental Care and Ontogenetic Diets Shifts in the Recruitment Variation of an Aquatic Predator
… and winter survival are predicted to determine year class strength of largemouth bass Micropterus salmoides . In Chapter Two, family-specific DNA fingerprints were used to quantify parental effects on brood-specific contribution to fall recruitment in environments that differed in the presence …
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Modeling the processes affecting larval haddock (Melanogrammus aeglefinus) survival on Georges Bank
… single most important natural event controlling year-class strength and biomass in fish populations. As evident in Georges Bank haddock, Melanogrammus aeglefinus, there is a strong relationship between recruitment success and processes occurring during the planktonic larval stage. Spatially …
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Population Dynamics of Common Carp in Eastern South Dakota Glacial Lakes
… severe winters can negatively affect common carp year-class strength. Therefore, I hypothesized that specific weather patterns may affect common carp survival during early life stages and thus subsequent recruitment. I examined three candidate models using the information-theoretic approach to …
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Status of Paddlefish in Lake Francis Case, South Dakota
… throughout much of their range. In the past 100 years, however, paddlefish populations have declined throughout their range. The construction of dams has been identified as a leading cause of population declines, as dams block spawning migrations, alter historic spawning habitats, and disrupt …
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