Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae

Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2014.

Bibliographic Details
Main Author: Hamady, Li Ling
Other Authors: Simon R. Thorrold.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2014
Subjects:
Online Access:http://hdl.handle.net/1721.1/87614
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author Hamady, Li Ling
author2 Simon R. Thorrold.
author_facet Simon R. Thorrold.
Hamady, Li Ling
author_sort Hamady, Li Ling
collection MIT
description Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2014.
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spelling mit-1721.1/876142019-04-10T15:06:56Z Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae Hamady, Li Ling Simon R. Thorrold. Woods Hole Oceanographic Institution. Joint Program in Oceanography/Applied Ocean Science and Engineering. Massachusetts Institute of Technology. Department of Biology. Woods Hole Oceanographic Institution. Joint Program in Oceanography/Applied Ocean Science and Engineering. Biology. Woods Hole Oceanographic Institution. Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2014. Cataloged from PDF version of thesis. Includes bibliographical references (pages 113-127). White sharks (Carcharodon carcharias) are highly migratory, ecologically important, vulnerable, and understudied marine predators. Ecogeochemistry, which takes advantage of natural variations in chemical signatures recorded in body tissues, can help determine lifetime movement, age, and ontogenetic diet history in difficult to study species. Shark vertebrae are constructed of distinct layers of tissue laid down sequentially over an individual's lifetime and may preserve a chemical record of environmental exposure. In this thesis, I investigate the ecology of the understudied northwest Atlantic (NWA) white shark population by applying several ecogeochemistry techniques to their vertebrae. I generate the first radiocarbon ([delta]¹⁴C) age estimates for adult white sharks, dramatically extending the maximum age and longevity compared to earlier age studies. [delta]¹⁴C results also verify a lack of reworking of vertebral material and hint at possible sexual dimorphism in growth rates. Using amino acid and bulk stable isotope analyses, I show that individual sharks have marked variation in feeding and movement, and that pinnipeds do not constitute a large portion of their diet. Finally, I explore the utility of elemental chemistry to retrospectively infer movement. This work provides an important informational baseline for future NWA white shark ecological studies and conservation and management efforts. by Li Ling Hamady. Ph. D. 2014-06-02T19:47:55Z 2014-06-02T19:47:55Z 2014 2014 Thesis http://hdl.handle.net/1721.1/87614 879661809 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 130 pages, 697-714 pages, 149-150 pages, 327-373 pages, 5 unnumbered pages, 203-204 pages, 16 unnumbered pages application/pdf Massachusetts Institute of Technology
spellingShingle Joint Program in Oceanography/Applied Ocean Science and Engineering.
Biology.
Woods Hole Oceanographic Institution.
Hamady, Li Ling
Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title_full Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title_fullStr Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title_full_unstemmed Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title_short Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
title_sort age movements and feeding ecology of northwest atlantic white sharks estimated from ecogeochemical profiles in vertebrae
topic Joint Program in Oceanography/Applied Ocean Science and Engineering.
Biology.
Woods Hole Oceanographic Institution.
url http://hdl.handle.net/1721.1/87614
work_keys_str_mv AT hamadyliling agemovementsandfeedingecologyofnorthwestatlanticwhitesharksestimatedfromecogeochemicalprofilesinvertebrae