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 18 of 18 for “"gillnet"”.
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Integrating traditional ecological knowledge in South Africa's small-scale fisheries: the Olifants Estuary Gillnet Fishery
Increasingly, managers and scientists are recognizing the importance of understanding small-scale fisheries as complex socio-ecological systems. As a result, managing fisheries is no longer only about managing fish but also about managing people. One mechanism for incorporating the human dimension …
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Investigating ecosystem-level effects of gillnet bycatch in Lake Erie: implications for commercial fisheries management
… Fishing Survey (PIS) data and the commercial gillnet logbook data. The bycatch of walleye, yellow perch and white perch was predicted by a delta model developed on the PIS data. Discards were estimated as the difference between predicted bycatch and landed bycatch. Results highlighted bycatch …
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Contextualising the bycatch 'problem' in the Olifants Estuary Small-Scale Gillnet Fishery using an Ecosystem Approach to Fisheries
… of the Olifants estuary small-scale traditional gillnet fishing community, located on the west coast of South Africa, provides a particularly relevant example of a complex fishery requiring a holistic approach. Current regulations prohibit the harvesting or retention of any bycatch species. …
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Fishery Interaction Modeling of Cetacean Bycatch in the California Drift Gillnet Fishery to Inform a Dynamic Ocean Management Tool
… to reduce bycatch. In the California drift gillnet fishery static management approaches and gear changes have reduced bycatch but neither measure ascertains the underlying dynamics causing bycatch events. To avoid further potentially drastic measures such as hard caps, dynamic management …
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Describing and Characterizing Potential Lemon Shark (Negaprion brevirostris) Nursery Habitat in Mississippi Coastal Waters
… exploration of the species. Data from long-term gillnet monitoring in conjunction with a focused gillnet study predominantly around Cat Island, MS was used to identify depth as the main factor influencing capture. Lemon Sharks were acoustically tagged to monitor movements throughout the system …
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Factors influencing the nursery dynamics of juvenile bull sharks in two estuaries along the Texas coast
… drumline sampling and historical long-term gillnet monitoring (1985-2018). In San Antonio Bay, the densities of larger sharks posing a threat to YOY bull sharks was highest in the months of May and June, and significantly influenced by location within the estuary. No predatory sharks were …
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Age, growth and per-recruit assessment of the Saldanha and Langebaan stock of Chelon richardsonii
… South Africa. They are the primary target of the gillnet and beach-seine fishery in this region. Despite being managed through a multifaceted approach of gear restrictions and total allowable e↵ort, the fishery is thought to be oversubscribed and the stock is regarded as being overfished. The …
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TROPHIC DYNAMICS OF THE LAKE SUPERIOR FISH COMMUNITY
… and length class during coordinated, standard gillnet and bottom-trawl surveys. To assess trophic linkages, gut contents were examined and biomass, count, and length were measured. Additionally, twelve common lean lake charr diet items were collected during summer 2022, analyzed for energy …
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Feeding ecology of the African tigerfish Hydrocynus vittatus castelnau, 1861 in the floodplains of the Kavango river, Namibia
… using a seine and an experimental multifilament gillnet, during the annual flooding period between February and May 2020. The result of the study shows a significant ontogenetic dietary shift (P < 0.05) between size classes of tigerfish. The study also find a significant different (P < 0.05) in …
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Effects of fishing on a coral reef fish assemblage in Northeastern Brazil
… catch rates more severely were hook and line, gillnet and cast net. Based on the results it is argued that the effects of reef fisheries on catch rates were highly depended on the vulnerability of target species. Finally, the dissertation assesses the ability of the fishing-down concept to …
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Understanding and mitigating seabird bycatch in the South African pelagic longline fishery
… many seabird populations worldwide, with trawl, gillnet and longline fisheries considered the most destructive to seabird populations. Seabird bycatch from trawl and gillnet fisheries has been significantly reduced in recent years, but large numbers of seabirds are still killed annually by …
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A comparative study on the fish species composition, diversity and catch rates among the fisheries reserves on the Zambezi and Kwando rivers, Zambezi region
… and the Kwando River (Luhingi and Qhuqhumupa). Gillnet surveys using both experimental and monofilament gillnets were conducted between 13 November and 13 December 2021. A total of 3,360 individual fish, representing 32 species, were captured. On the Zambezi River, Makangala had the highest …
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Bycatch and foraging ecology of sea turtles in the Eastern Pacific
… per species and country in trawl, longline, and gillnet fisheries, and to compile results of mitigation measures. Moreover, estimates for current annual capture rates in trawl fisheries were obtained and compared with population numbers. </p><p>This regional bycatch used all the information …
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Delination of Coastal Shark Habitat within North Carolina Waters Using Acoustic Telemetry, Fisher-Independent Surveys, and Local Ecological Knowledge
… Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys were used to spatially delineate potential habitat for six species within Pamlico Sound. Inlet distance and temperature were among the most influential environmental factors associated with species presence, while …
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Approaches to assessing the status of nearshore and estuarine fish and fisheries and their responses to environmental change
… the recreational shore and commercial seine and gillnet fisheries and only 7% of the catch of the recreational spearfishery and commercial and recreational boat fisheries. Total value of estuarine and estuary-dependent fisheries was estimated to be R1.594 billion per annum in 2008 rands. The …
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Bayesian hierarchical approaches to analyze spatiotemporal dynamics of fish populations
… in Lake Erie based on data from a 27-year gillnet survey, and analyzed the impacts of environmental factors on spatiotemporal dynamics of the population. I found that yellow perch relative biomass index displayed clear temporal variation and spatial heterogeneity, however the two middle MUs …
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Population biology of two key fish species and the dynamics and management of the trap fishery in Beung Borapet, Thailand
… otoliths. The catch composition of the trap and gillnet fishery in Beung Borapet was dominated by five species, namely P. fasciatus, N. notopterus, Oreochromis niloticus, Cyclocheilichthys repasson and Cyclocheilichthys apogon. Traps tended to catch larger fish of more marketable size than gill …
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Population structure and genetic variation in Hector’s dolphin (Cephalorhynchus hectori)
… populations more stringent control of inshore gillnet fisheries is required. By contrast, current decline of the North Island population may be a result of inbreeding depression. Given the low abundance and rapid decline of the North Island population, it is imperative to evaluate the potential …