Changes in Target Species and Spatial Population Structure in Stock Assessment Models for Highly Migratory Pelagic Fish ...

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Material Information

Title:
Changes in Target Species and Spatial Population Structure in Stock Assessment Models for Highly Migratory Pelagic Fish Stocks as Exemplified by the South Atlantic Blue Shark
Physical Description:
1 online resource (155 p.)
Language:
english
Creator:
Carvalho, Felipe Correia
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Fisheries and Aquatic Sciences, Forest Resources and Conservation
Committee Chair:
MURIE,DEBRA JEAN
Committee Co-Chair:
AHRENS,ROBERT
Committee Members:
PARKYN,DARYL CHARLES
PONCIANO CASTELLANOS,JOSE MIGUEL
BIGELOW,KEITH A
CARLSON,JOHN K
HAZINS,FABIO

Subjects

Subjects / Keywords:
assessment -- elasmobranch -- migration -- selectivity -- stock
Forest Resources and Conservation -- Dissertations, Academic -- UF
Genre:
Fisheries and Aquatic Sciences thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
In 2008 The International Commission for the Conservation of Atlantic Tunas (ICCAT) encouraged future research on movement patterns, habitat utilization, and different stock assessment models that would allow incorporation of these types of information to improve the quality and reduce uncertainty in future Atlantic blue shark (Prionace glauca) stock assessments. Furthermore, the ICCAT working group on assessment methods also expressed concern that some CPUE series used in the assessments might be misleading due to changing fishing strategies within the fishery, such as changes in target species. My dissertation proposal addresses this necessity and focuses on investigating the movements of the South Atlantic blue shark stock using Pop-up Satellite Archival Tags (PSAT), as well as developing and comparing the predictions of a series of stock assessment models for the South Atlantic blue shark. Chapter 2 presents a suite of Bayesian state-space production models fitted to the time series of a South Atlantic blue shark stock in which a single change point in the stationary distribution of the catchability coefficient is specified in order to capture a significant change in target species (hence catchability) in the Brazilian longline fishery. Accounting for a single change point in the catchability coefficient had no significant impact on the status of South Atlantic blue shark (still above BMSY); however, it provided a robust way of accounting for changes in catchability as a result of changing target species. In Chapter 3, satellite telemetry and random mixed-models were used to quantify the factors driving movement patterns in blue sharks across the South Atlantic Ocean. The majority of sharks showed a residency to core areas and showed patterns of vertical segregation between adults and juveniles. In chapter IV, the effectiveness of integrating the vertical spatial structure of the south Atlantic blue shark population in Statistical catch-at-age models (SCAM) was evaluated. Although accounting for vertical spatial structure had no significant impact on the status of SA blue sharks (still above SSBMSY), the model provided a simpler method to capture some of the complexities of a spatially-structured situation.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Felipe Correia Carvalho.
Thesis:
Thesis (Ph.D.)--University of Florida, 2014.
Local:
Adviser: MURIE,DEBRA JEAN.
Local:
Co-adviser: AHRENS,ROBERT.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2014-11-30

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0046481:00001