HCNSO Student Theses and Dissertations

Copyright Statement

All rights reserved. This publication is intended for use solely by faculty, students, and staff of Nova Southeastern University. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Defense Date


Document Type

Thesis - NSU Access Only

Degree Name

M.S. Marine Biology

Second Degree Name

M.S. Coastal Zone Management


Oceanographic Center

First Advisor

Mahmood Shivji

Second Advisor

Enric Cortes

Third Advisor

Richard Spieler


The best available biological information for the silky shark, Carcharhinus falciformis, was used to produce a demographic analysis for the silky shark population off the southeastern U.S. Monte Carlo simulation was used to vary natural mortality (M), fecundity (mx), age-at-maturity (tmat) and longevity (tmax) to account for some of the uncertainty in these vital rates. Demographic analyses were run 1000 times to allow estimation of 95% confidence intervals. Under the scenario of natural mortality only, results indicated the silky shark population would grow at a rate of 4.5 %/year (R0 = 2.038, G = 16.223, and r = 0.044). Adding the latest available fishing mortality estimate (F) for large coastal sharks resulted in a population decreasing at a rate of 4.8%/year. Finally, to incorporate the hypothetical effect of gear selectivity on fishing mortality, length frequencies for silky sharks caught on longlines off the southeastern U.S. were used to estimate gear selection at various ages. Demographic analyses that consider hypothetical gear selection, when compared to analyses using constant across-age mortality models, suggest that gear selectivity and the resulting fishing mortality-at-age may be an important influence on demographic model output, and should be considered where possible when using demographic analyses as management tools.

To access this thesis/dissertation you must have a valid nova.edu OR mynsu.nova.edu email address and create an account for NSUWorks.

Free My Thesis

If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the Free My Thesis button.

  Link to NovaCat