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dc.contributor.authorKelly, Cian
dc.date.accessioned2019-08-29T07:10:04Z
dc.date.available2019-08-29T07:10:04Z
dc.date.issued2019-08-16
dc.date.submitted2019-08-15T22:00:02Z
dc.identifier.urihttp://hdl.handle.net/1956/20734
dc.description.abstractFish species that exhibit sporadic recruitment, late maturity and that are long-lived, can be difficult to manage. The issue arises from the high variability in stock dynamics. Where there are significant interannual fluctuations in biomass, it is difficult to harvest the population in a sustainable manner, avoiding stock collapse while maintaining high yields and catch stability. The aim of this project was to inform the management of species with the above stock characteristics through computer simulation of two Harvest Control Rules (HCRs) using Management Strategy Evaluation (MSE). MSE is a method used to simulate the performance of different management strategies under different criteria. HCRs are the flexible management rules which convert biological information into catch advice. Both management tools have become increasingly common in fisheries management. Escapement HCRs are most commonly used for the conservation of the spawning population in short-lived species such as Atlantic salmon (Salmo salar). In this study, the utility of a Novel HCR, which reflected an Escapement HCR, was tested on a stock whose dynamics was informed by Greenland halibut (Reinhardtius hippoglossoides). The Novel HCR was formulated to conserve the biomass from spikes in recruitment of a long-lived species, by exclusively targeting the fraction of biomass above a threshold biomass level. The performance of this Novel HCR was compared to a traditional ‘hockey-stick’ ICES HCR through MSE using the FLBEIA model in R software. The model results indicated that there were trade-offs between the two HCRs. The Novel HCR provided relatively high yields with low risk of stock collapse, but came at the cost of a high fraction of moratoria and high interannual variability in catches. Depending on the management objectives, the Novel HCR can be successfully used in the sustainable exploitation of long-lived species with sporadic recruitment. The results of this paper will help to inform the management of Greenland halibut in the Barents Sea.en_US
dc.language.isoeng
dc.publisherThe University of Bergenen_US
dc.subjectHCR
dc.subjectsimulation modelling
dc.subjectBlim
dc.subjectBtrigger
dc.subjectSSB
dc.subjectFLBEIA
dc.subjectMSE
dc.subjectFtarget
dc.titleEvaluating the utility of a Novel Harvest Control Rule in the management of long-lived sporadically recruiting species through Management Strategy Evaluation
dc.typeMaster thesis
dc.date.updated2019-08-15T22:00:02Z
dc.rights.holderCopyright the Author. All rights reserveden_US
dc.description.degreeMaster's Thesis in Biologyen_US
dc.description.localcodeBIO399
dc.description.localcodeMAMN-BIO
dc.subject.nus751999
fs.subjectcodeBIO399
fs.unitcode12-60-0


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