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 “"Fisheries data"”.
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Assessment of patterns in the Namibian hake fishery based on commercial fisheries data, in relation to environmental factors
… explores the relationships between commercial data and those obtained from research surveys in an attempt to broaden the database available for management, and to cover seasonal and inter-annual changes in density estimates of Cape hake (Merluccius capensis). It also attempts to explain hake …
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UK fisheries, climate change and North Sea fishes: a long-term perspective
Abstract North Sea demersal fishes and fisheries have changed over the past 100 years. To detect the main factors driving these changes, long-term data are needed. Using historical fisheries data that extend throughout the 20th century, this thesis aims to assess drivers influencing developments in …
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Multiple-Species Models for True Abundances Allowing for Heterogeneity of Capture Between and Within Species
… settings. We demonstrate our methods with a fisheries removal example; our techniques are then applied to several other fisheries data sets. We evaluate our methods on a series of test data sets we constructed using empirical probabilities of capture. Finally, multiple simulations were run to …
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A Spatial Analysis of Changes in Recreational Fishing Pressure on the Central Coast of California Subsequent to MPA Implementation
… including conservation and restoration of fisheries, but few studies assess how MPAs affect regional fishing patterns. Previous research suggests effort will intensify at MPA edges, but few datasets include sufficient pre-implementation data to quantify how MPAs alter fishing effort. We …
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Human activities in the deep North Atlantic
… management of the oceans requires data on the extent of human impacts and the wider availability of data on human activities. This study, which aimed to provide the first detailed assessment of the extent of human activities in the deep North East Atlantic, OSPAR Maritime Area, …
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The impact of cormorants (Phalacrocorax carbo carbo and Phalacrocorax carbo sinensis) on inland fisheries in the UK
… presence of cormorants, feeding daily on their fisheries, has a damaging impact on fish stocks with inevitable financial losses. Due to a lack of effective non-lethal control methods, the angling bodies wish to see the cormorants removed from the protected species list so their inland numbers …
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Sedimentary legacy of sockeye salmon (Oncorhynchus nerka) and climate change in an ultra-oligotrophic, glacially-turbid British Columbia nursery lake
… depressed, sockeye returns. Climate and fisheries data supplemented with local and traditional knowledge (LTEK) indicated that sockeye escapements were regulated by both harvest and climate over the period of record. The sedimentary record of Kitlope Lake indicated extremely high …
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Sedimentary legacy of sockeye salmon (Oncorhynchus nerka) and climate change in an ultra-oligotrophic, glacially-turbid British Columbia nursery lake
… depressed, sockeye returns. Climate and fisheries data supplemented with local and traditional knowledge (LTEK) indicated that sockeye escapements were regulated by both harvest and climate over the period of record. The sedimentary record of Kitlope Lake indicated extremely high …
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Resetting marine environmental baselines for the United Kingdom: what have we really lost?
The systematic collection of data on fish stocks now used to inform fisheries management began only a few decades ago, however, these data do not provide a true picture of change as commercial fishing began many centuries earlier. Historical information such as that found within old photographs, …
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The impact of bias in length frequency data on an age structured fisheries stock assessment model
… age-structured models are widely used in fisheries stock assessment. These models have been become increasingly complex over recent decades, allowing them to incorporate a larger variety of fisheries data. These typically include information regarding annual fishery yields, indices of …
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The siting of renewable energy developments in a crowded marine space
… over time, with increased representation of fisheries voices. At both a project level and strategic level, constructive communication between the energy and fisheries sectors was found to be as important for fostering procedural justice as sufficient fisheries data. However, compared to …
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Bayesian hierarchical approaches to analyze spatiotemporal dynamics of fish populations
… the most important commercial and recreational fisheries in Lake Erie, which is currently managed using four management units (MUs), with each assessed by a spatially-independent stock-specific assessment model. The current spatially-independent stock-specific assessment assumes that movement of …
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Identifying limitations of monitoring the success of river rehabilitation schemes for freshwater fish
… flood protection, navigation and transportation, fisheries and recreation. Rehabilitation of rivers is a tool that underpins the Water Framework Directive (WFD) by means of addressing river degradation by re-introducing habitat heterogeneity to impacted river systems. Many past and recent papers …
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Assessing variability in standardised harvest rates from shore-based recreational fishing surveys
… rates for both commercial and recreational fisheries, however, the use of this technique in shore-based recreational fisheries are few and have not yet been applied to fisheries data collected in Western Australia. The focus of this study is on assessing generalised linear models (GLM) that …
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Status and Contribution of Small-scale Fisheries in Menabe, Southwest Madagascar
Small-scale fisheries are critical for food security, nutrition, and livelihoods in Madagascar, yet remain poorly understood due to chronic data deficiency and underreporting. Madagascar’s dispersed and often mobile coastal communities depend heavily on marine resources particularly the Vezo …
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Historical baselines and a century of change in the demersal fish assemblages on South Africa's Agulhas Bank
… and historical states. The onset of systematic fisheries data collection typically lagged decades or even centuries behind modern fishing exploits. As a consequence, pre-disturbed reference points and descriptions of subsequent change are rarely available. A remarkably detailed set of historical …
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The value of catch statistics and records of Guano Harvests for managing certain South African Fisheries
… is shown from results obtained using artificial fisheries data that the database conventionally considered adequate for VPA work, viz. the catch mass and age structure, does not lead to reliable estimates of stock abundances for recent years. Use of further data related to stock adundance, such …