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 50 for “"fish population"”.
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Spatial and temporal dynamics of an exploited reef-fish population
The successful management of the fishery for galjoen Dichistius capensis depends on an understanding of its spatial and temporal dynamics. This thesis investigates the movement of galjoen and its fishery parameters, and evaluates the role of marine protected areas (MPAs) and alternative assessment …
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Fish population and behavior revealed by instantaneous continental-shelf scale imaging
… abundance, spatial distribution, and behavior of fish populations over thousands of square kilometers using Ocean Acoustic Waveguide Remote Sensing (OAWRS) is demonstrated with data from its first implementation in a 2003 field experiment off the US Continental Shelf south of Long Island, NY. …
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An evaluation of systematic error in the estimation of fish population size
… used to estimate the size of a pumpkinseed sunfish (<i>Lepomis gibbosus</i>) population in a 1.16 hectare Virginia farm pond. After estimates were obtained, the pond was drained in order to compare estimated population size with actual population size. In all cases, population estimates were …
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The Fish Population of Lake Poinsett, South Dakota, as Indicated By the Catch
… shocker were utilized to obtain samples of the fish population of Lake Poinsett, South Dakota. The species and size composition of the samples differed significantly with time of season, time of day, location on the lake, and type of gear. Decreased activity following spawning was the apparent …
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A comparison of individual-based and matrix projection models to applied to fish population and community dynamics
… commonly used for the analysis and management of fish populations. Matrix models break down the population into age or stage classes, while IBMs track individuals. I perform a series of quantitative comparisons between the predictions of the two modeling approaches using the IBM as the standard of …
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An assessment of the reliability of fossil pilchard and anchovy scales as fish population indicators off Namibia
Fossil fish scales hold potential for ellucidating past fish population fluctuations. A system of classification for scales from the pilchard, Sardinops ocellata, and the anchovy, Engraulis capensis, is presented. Both species show an unexpected range of scale types. The classifications reduce …
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Recovery of the Fish Population of a Municipal Wastewater Dominated, North Texas Creek After a Major Chlorine Disturbance
… the effects of a major chlorine disturbance on fish communities in Pecan creek by the City of Denton's Pecan Creek Water Reclamation Plant. Fish communities in Pecan Creek were sampled using a depletion methodology during February, April, July, and November, 1999. February and April sampling …
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Predicting salmonid population ecology from individual fish responses to environmental changes: bridging behaviour, conservation and fisheries management.
… and ecologically important chalk stream salmonid populations fail to incorporate fish behaviour and the interactions between fish with their environment and this limits their ability predicting management-relevant salmonid population responses to environmental change. A salmonid individual-based …
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Predicting the ecological consequences of river management for a riverine cyprinid fish.
… decisions should be evidenced-based, current population and habitat models fail to incorporate fish behaviour and the interactions between fish and their environment, thus limiting their ability to predict management-relevant, population responses to environmental change. In order to address …
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Mark-Recapture Creel Survey and Survival Models
… to the estimation of exploitation rate of a fish population by combining mark-recapture procedures with a creel survey. We also consider the analysis of a proportional hazards survival model for randomly censored observations, known as the Koziol-Green model. The model assumes that the …
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The impact of cormorants (Phalacrocorax carbo carbo and Phalacrocorax carbo sinensis) on inland fisheries in the UK
… between winter 1987/88 and 1990/91, and the population is still believed to be rising. The population growth was observed in all regions of the UK, on all habitat types. As cormorants exploited new habitats, ornithologists welcomed their increased presence. This contrasts with the views of …
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Habitat Requirements and Foraging Ecology of the Madagascar Fish-Eagle
With a population estimate of 99 pairs, the Madagascar fish-eagle (Haliaeetus vociferoides) is one of the rarest birds of prey in the world. I investigated the ecological requirements of the Madagascar fish-eagle in 1994 and 1995 to help determine management action to prevent its extinction. I …
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A Toxicological Analysis of Exposure Magnitude, Duration, and Frequency and the Significance for Monitoring and Management of Episodic Pollution Events
Information on organism and population effects was then expanded through the use of toxicity and population modeling. Several toxicity models were evaluated against organism effects of single and multiple exposures and appropriate models were used to expand the analysis of organism effects to …
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A comparison of growth rates of coarse fish in gravel-pit lakes in south-east England and of population structure in selected lakes
Age and growth rates of the coarse fish of 39 gravel-pit lakes in South-East England are compared. Species composition and growth rate are very variable, the commonest species being roach (Rutilus rutilus L.), bream (Abramis brama L.), tench (Tinca tinca L.), perch (Perca fluviatilis L.) and pike …
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Understanding links between flow regime and fish populations in the Saskatchewan River Delta
… are essential to maintain sustainable fish populations. Abiotic environmental conditions can influence recruitment and the resulting ability to harvest adult fish. In rivers, the flow regime dictates water depths and velocities that subsequently trigger spawning and enable the survival …
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Effects And Interactions Of Antibiotic, Butyrate, And Temperature On Sailfin Molly (Poecilia Latipinna) Metabolism And Gut Microbiota
… microbiome dynamics is crucial for optimizing fish health and growth, particularly in aquaculture settings. This study examines the effects of antibiotic, butyrate, and temperature treatments on the metabolism and gut microbiota of sailfin molly (Poecilia latipinna) alone and in combination. …
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Water quality and productivity changes associated with the liming of a soft water lake
Sherwood Lake, a 165 acre public fishing impoundment in Greenbrier County, West Virginia, was treated with calcium carbonate for four years. The limestone treatment was done by revolving limestone drums installed above the lake on Meadow Creek. The limestone drum provided continuous treatment …
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Public and professional perspectives of Virginia's stream and river resources
… selected Virginia residents. All 169 Virginia fisheries biologists and game wardens were sent a similar but shorter questionnaire. The survey was designed to: 1) determine the relative importance of selected stream and river characteristics to public and professional respondents; 2) identify …
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Host Specificity of Freshwater Mussels: a Critical Factor in Conservation
… a unique life cycle in which they parasitize a fish host during their larval stage. While fish hosts of many mussel species have been identified, little is known of variation in host-specificity among populations, within species. I investigated host compatibility in two populations of the …
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Assessing the Sustainability of Fish Communities in Glacial Lakes: Habitat Inventories and Relationships Between Lake Attributes and Fish Communities
… relationships between habitat variables and the fish communities in large lakes. The objectives of my research were to: 1) quantify the available aquatic habitats in 15 South Dakota large lakes, 2) investigate the use of Geographical Information System technology to create aquatic habitat layers, …
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