Global ETD Search
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Showing 1 to 19 of 19 for “"spawning stock"”.
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Regional Variation in Migratory Behavior and Reproductive Output of The Gulf Of Mexico Blue Crab Spawning Stock
… the structure and boundaries of the blue crab stock(s) in the Gulf of Mexico, focusing on large-scale movements of spawning female crabs. Because spawning location is a primary determinant of larval transport pathways, understanding spawning locations and offshore movements of female blue crabs …
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On the reproductive biology of the western Atlantic bluefin tuna, Thunnus thynnus
… throughout the North Atlantic Ocean, but spawning is known to occur only in the Mediterranean Sea and the Gulf of Mexico/Straits of Florida. The regulatory body charged with managing Atlantic bluefin tuna, the International Commission for the Conservation of Atlantic Tunas (ICCAT), …
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The Impact of Multiple Nursery Areas on the Population Structure of Atlantic Menhaden, <i>Brevooria tyrannus</i>
… In addition to a decrease in overall numbers and spawning stock biomass, recruitment levels have remained low since the 1990s. Menhaden use numerous estuaries along the Atlantic coast for juvenile development before recruiting to the adult population and the contribution of each of these nursery …
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An individual-based modelling approach to examine life history strategies of sardine Sardinops sagax in the southern Benguela ecosystem
Hypotheses regarding the spawning strategy and recruitment of sardine (Sardinops sagax) in the southern Benguela ecosystem are tested using an individual-based Lagrangian particle tracking model linked with a 3-D hydrodynamic model of the region. Experiments focus on the dispersion of eggs and …
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A comparison of advanced time series models for environmental dependent stock recruitment of the western rock lobster
… has been applied to the environmental dependent stock and recruitment relationships for crustacean species in Western Australian fisheries. Alternative models, such as transfer function models and state space models have the potential to provide unproved forecasts for these types of data sets. …
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Reassessment of the Red Drum Stock in Mississippi Coastal Waters: The Role of Ages 3-5 Year-Class Fish
… of Red Drum in federal waters. Monitoring of the stock in Mississippi state waters occurs at sites that are almost exclusively estuarine, using gear types selective for juvenile fish. Additional samples come from the for-hire-industry that typically targets larger Red Drum. This project’s goal was …
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Spatial Distribution and Stock-Recruitment Analysis of the Atlantic Surfclam, <i>Spisula solidissima</i>, in the Mid-Atlantic Bight and on Georges Bank
… bottom waters is driving the surfclam stock into new habitat and extirpating the surfclams from nearshore areas. Based on a species distribution function model, the small surfclams appear to inhabit a greater area than the large market-size surfclams across the entire stock. The wider …
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The Response of a protandrous species to exploitation, and the implications for management: a case study with patellid limpets
… between egg and zygote production, and spawning stock biomass (SSB) and fishery yield for a range of P. vulgata populations across a wave exposure gradient. The effect of different management strategies, minimum landing size or marine protected areas, on the relationship between …
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The fisheries biology of two scallop species, Pecten maximus (l.) and Aequipecten opercularis (l.), in the waters around Shetland, Scotland.
… to implement local management of<br/>shellfish stocks, where necessary. The collection of biological data was started<br/>and the completion of log books begun in 1999 and 2000, respectively, to<br/>provide data to assess the species, with a view to their sustainable<br/>management.<br/>Von …
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The importance of female phenotype in determining reproductive potential and recruitment in Atlantic coast striped bass (Morone saxatilis)
… shaping maternal phenotype was evaluated using a spawning stock time-series to evaluate possible environmental drivers of female migration timing in the Chesapeake Bay. Results showed that local and recent water temperature was the primary factor influencing timing of movement onto spawning …
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Yellow perch in Lake Michigan: investigating size-selective mortality and alternative estimators of age
… However, the interplay of both biotic (i.e. spawning stock biomass and predation) and abiotic (i.e. water temperature and currents) factors throughout pre-recruit life stages makes recruitment predictions challenging. A combination of multiple variables is likely responsible for year-class …
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Maturation, Fecundity, and Spawning Frequency of the Albemarle/Roanoke Striped Bass Stock
… in North Carolina, the Albemarle/Roanoke (A/R) stock has grown tremendously in size and age structure over the last twenty years necessitating an up-to-date maturity and fecundity schedule. The last study was conducted for the Albemarle Striped Bass Management Board in 1989-1990 by Olsen and …
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The Relative Contribution of Hudson River Tributaries to River Herring Spawning Dynamics
… tributary contribution to anadromous fish spawning dynamics is irrefutably important when prioritizing habitat enhancement, restoration and management decisions (Everly and Boreman, 1999). Collecting sound baseline data becomes critical when seeking out the most significant contributors to …
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The use of multibeam and split-beam echo sounders for assessing biomass and distribution of spring-spawning Atlantic cod in the Gulf of Maine
… a relative measure of abundance of the spring-spawning Atlantic cod (Gadus morhua) in the western Gulf of Maine. Specifically, the main objectives of this research were 1) to test the feasibility of a multibeam echo sounder to detect changes in volume backscatter proportional to incrementally …
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Incorporating Migration and Local Movement Patterns into Management Strategies for Spiny Dogfish (Squalus acanthias)
… which suggests that the northwestern Atlantic stock could comprise as many as five behaviorally distinct groups of Spiny Dogfish. The work presented in this dissertation identifies predictable behavioral patterns undertaken by individual Spiny Dogfish and inferred from recapture data, which can …
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The implementation of a management procedure approach to set catch limits for the Southern Bluefin Tuna and the Atlantic Bluefin Tuna
… of Atlantic Tunas (IC- CAT) in relation to stocks of bluefin tuna. These approaches aim to provide a simple and widely agreed way to calculate annual catch limits that will lead to meeting fishery management objectives such as attaining or maintaining reasonably large catches in the future, …
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The rise and fall of the spiny lobster (Jasus edwardsii) in the Hauraki Gulf, northeastern New Zealand
… assessment suggests improvements in the wider stocks, fisheries-independent assessments are needed to evaluate this. Furthermore, ocean warming has resulted in the expansion of long-spined sea urchins (Centrostephanus rodgersii) in northeastern New Zealand, and it is unknown if this has been …
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Function and diversity of the Ship, Trinity, and Tiger Shoal Complex, with emphasis on macrofauna and spawning blue crabs (Callinectes sapidus)
… as offshore blue crab (Callinectes sapidus) spawning grounds. I discovered unexpectedly high concentrations of spawning female blue crabs, greatly expanding what was previously understood about blue crab reproductive migrations. Blue crab abundances were significantly higher on Ship and …
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Spatial and temporal heterogeneity in life history and productivity trends of Atlantic Weakfish (Cynoscion regalis) and implications to fisheries management
The biological characteristics of fisheries stocks that are assessed for management considerations are rarely homogeneous over time or space. However, stock assessment scientists largely ignore this heterogeneity in their models. This thesis addresses the effects of spatial and temporal …