Date of Award

Fall 2017

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Ocean/Earth/Atmos Sciences

Committee Director

Cynthia M. Jones

Committee Member

Alexander Bochdansky

Committee Member

Norou Diawara

Committee Member

Thomas Miller

Abstract

Blueline tilefish (Caulolatilus microps) have recently undergone an increase in landings from waters off the US Mid-Atlantic region (Virginia-Massachusetts). Currently, life history characteristics of blueline tilefish in this area are undescribed. Additionally, appropriate indices of population abundance are not available for this region, necessitating the use of data-limited management methods to set restrictions for harvest of blueline tilefish in this area. This dissertation describes growth and reproductive characteristics of blueline tilefish caught off the coast of Virginia and explores improvements of data-limited management methods that have been applied to blueline tilefish in the US Mid-Atlantic. Blueline tilefish from the US Mid-Atlantic show a similar growth pattern to fish caught off North and South Carolina prior to the rise of commercial fishing for blueline tilefish in this area. This growth pattern is dissimilar from that observed more recently for fish from the US South Atlantic (east coast of Florida-North Carolina), with fish in the US Mid-Atlantic growing more slowly to larger maximum lengths. Blueline tilefish from the US Mid-Atlantic are gonochoristic multiple batch spawners that spawn, on average, every 1.44 days from May-November, with annual fecundities up to 50,000,000 oocytes for the largest individuals. Batch fecundity is correlated with total length in a similar fashion as seen previously in the US South Atlantic. These studies are the first to characterize growth and reproduction of blueline tilefish from the US Mid-Atlantic. Sensitivities of modal estimates and variabilities of total allowable catch (TAC), from data-limited management procedures (MP) applicable to blueline tilefish, to input values were analyzed to determine which inputs most impacted TAC. Natural mortality and mean maximum length from the von Bertalanffy growth equation had the greatest impacts. A composite MP was developed to incorporate distributions of TAC estimates from multiple MPs into a single, combined distribution that could be used to estimate a composite TAC. These analyses provide information that may enhance decision-making for management of data-limited fish stocks, such as blueline tilefish.

DOI

10.25777/rydf-t328

ISBN

9780355832747

ORCID

0000-0002-6166-667X

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