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dc.contributor.authorLeaf, Robert Thomasen
dc.date.accessioned2014-03-14T20:15:07Zen
dc.date.available2014-03-14T20:15:07Zen
dc.date.issued2010-06-22en
dc.identifier.otheretd-08122010-063252en
dc.identifier.urihttp://hdl.handle.net/10919/28636en
dc.description.abstractRecent empirical studies have demonstrated inter-generational morphological and life-history changes in fish stocks that have been impacted by size-selective harvest. Evolutionary processes in biological populations occur through differential survival and reproductive success based, in part, upon individual phenotypic variability. Fishing is a source of directional selection resulting in the directed removal of some phenotypes; however, many aspects of the evolutionary effects of fishing remain have yet to be described. In order to better understand the life-history and morphological changes that occur as a result of size-selective fishing, and their effect on fishery dynamics, I first determined the suitability of Japanese medaka (Oryzias latipes) for selection experiments. I performed selection experiments using Japanese medaka and report how morphology and life-history characteristics changed over multiple generations of selection. I then used these patterns of change in life-history and morphology to validate individual-based simulation candidate models to test general mechanisms of life-history relationships. Finally, I applied the individual-based simulation modeling approach in order to describe how biological and fishery characteristics change in a large, age-structured population exposed to size-selective fishing over multiple generations. I found that the Japanese medaka has attractive characteristics for biological investigation. The selection experiments indicated large changes in the age-atmaturity, including a nearly 50% decrease over four generations in the most intense sizeselective removal regimes. However, I did not observe significant changes in length-at-age or weight-at-age over the course of the experiment. Candidate simulation models were poor at predicting some aspects of the life-history characteristics of Japanese medaka. The simulation model to determine fishery characteristics predicted large decreases in yield and egg production as a result of decreases in length-at-age. Understanding the relationships of life-history characteristics and their role in determining population resilience is a step toward understanding the importance of evolutionary processes in fishery management.en
dc.publisherVirginia Techen
dc.relation.haspartLEAF_Dissertation_2010.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectKeywords: Japanese medakaen
dc.subjectOryzias latipesen
dc.subjectaquacultureen
dc.subjectlife-history evolutionen
dc.subjectquantitative geneticsen
dc.subjectheritabilityen
dc.subjectindividual-based modelen
dc.subjectfishery-induced evolutionen
dc.titleThe Evolutionary Effects of Fishing: Implications for Stock Management and Rebuildingen
dc.typeDissertationen
dc.contributor.departmentFisheries and Wildlife Sciencesen
dc.description.degreePh. D.en
thesis.degree.namePh. D.en
thesis.degree.leveldoctoralen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineFisheries and Wildlife Sciencesen
dc.contributor.committeechairJiao, Yanen
dc.contributor.committeememberHallerman, Eric M.en
dc.contributor.committeememberMurphy, Brian R.en
dc.contributor.committeememberBerkson, James M.en
dc.contributor.committeememberPrager, Michael H.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08122010-063252/en
dc.date.sdate2010-08-12en
dc.date.rdate2010-08-25en
dc.date.adate2010-08-25en


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