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Habitat Utilization and Salinity Tolerance of the Sandbar Shark, Carcharhinus Plumbeus, in Virginia

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W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 2006 Habitat Utilization and Salinity Tolerance of the Sandbar Shark, Carcharhinus plumbeus, in Virginia Leonard Pace College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Fresh Water Studies Commons, Oceanography Commons, and the Zoology Commons Recommended Citation Pace, Leonard, "Habitat Utilization and Salinity Tolerance of the Sandbar Shark, Carcharhinus plumbeus, in Virginia" (2006). Dissertations, Theses, and Masters Projects. Paper 1539617845. https://dx.doi.org/doi:10.25773/v5-h0nc-6t94 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Habitat Utilization and Salinity Tolerance of the Sandbar Shark,Carcharhinus plumbeus, in Virginia A Thesis Presented to The Faculty of the School of Marine Science The College of William and Mary in Virginia In Partial fulfillment of the Requirements for the Degree of Master of Science By Leonard Jason Reed Pace 2006 APPROVAL SHEET This thesis is submitted in partial fulfillment of The requirements for the degree of Master of Science Leonard J.R. Pace Approved, December 2006 <v>s^-jQhn)A. M usics Ph?D. Committee Chairman/Co-Major Advisor Richard W. Brill, Ph.D. NOAA/NMFS, VIMS CMER Co-Major Advisor C35L Peter G. Bushnell, Ph.D. Indiana University, South Bend South Bend, Indiana John M. Brubaker, Ph.D TABLE OF CONTENTS Acknowledgements............................................................................................................ ii List of Tables.....................................................................................................................iii List of Figures ................................................................................................................... iii Explanation of Thesis Construction...............................................................................iv Abstract.............................................................................................................................. 2 1. Introduction...................................................................................................................3 2. Materials and Methods................................................................................................. 6 2.1.1 Animal Husbandry (sandbar sharks)..............................................................6 2.1.2 Animal Husbandry (dusky sharks)................................................................. 7 2.2.1 Experimental Procedures................................................................................. 7 2.2.2 Blood and Plasma Sampling............................................................................8 2.3 Data Analysis........................................................................................................ 9 3. Results .............................................................................................................................10 3.1 Animal Condition................................................................................................. 10 3.2 Whole Blood and Plasma.................................................................................... 11 4. Discussion.......................................................................................................................13 5. Conclusions.................................................................................................................... 20 Figures and Tables..............................................................................................................21 Appendices: A - Life History....................................................................................................30 B - Extended Materials and Methods................................................................33 C - Fishery.............................................................................................................35 D - Elasmobranch Osmoregulation...................................................................37 Literature Cited................................................................................................................. 41 Vita......................................................................................................................................49 ACKNOWLEDGEMENTS First and foremost I thank God, through whom all things are possible and without whom I could not have succeeded in finishing this project and all that it required. I would like to thank Dr. Jack Musick, for accepting me into the Shark Ecology program and for his unwavering support and help throughout my time at VIMS. I would also thank my two Wachapreague dads, Drs. Richard Brill and Peter Bushnell for their tireless assistance with pool construction, lab work, sharking, if you could call that work, and throughout the writing process. I owe a great deal of thanks to Dr. John Brubaker for dedicating his time and genuine interest in work far different from his own. I want to thank Drs. Benjamin Cuker, Linda Schaffner, Deidre Gibson, and the Hall-Bonner program for supporting my research efforts. A large part of who I am and what I have experienced is a result of Dr. Cuker’s steadfast support and the connections that support has provided and my gratitude is immeasurable. I am very grateful for the work of everyone at the Eastern Shore Lab. Dr. Mark Luckenbach, A1 Curry and Linda Ward’s time and attention was most helpful and I am happy to see that the lab’s unique conditions and available space have been getting increased attention throughout my summers there. Reade Bonniwell and Sean Late’s work deserve special thanks, as they put special effort into helping me construct my aquarium setup and transporting the duskys. I thank Josh for all his help with longlining, otherwise there would have been no duskys to transport. I would be remiss not to thank Dr. George Gilchrist who helped me fight through the statistics and R. The Council House family, immediate and extended, made the nights on the shore fun and helped break up the work. I will miss musical nights with Drij, Becca, Lenny2, Raija, Chris, PKS, Tommy, Coley, and John and I would like to thank them for their help in shark-sitting, covering pump flushes and making every summer enjoyable and memorable. I could not have survived the first year struggle without those long study dinners at Applebees and late nights in the LSL meeting room with the Team; Noelle, Kathleen, Erica, and Heidi. I am also deeply appreciative for Karen and the hope for the future and joy in the present that has come as a result of her being my life and all that she has taught me and helped me to find for myself. I must thank the other Burgh Westra bandits, Roix, my riding partner, roommate, hunting and fishing coach, and friend and Brandied Truffles for always putting a smile on my face. I am very grateful to have had Todd as an officemate, who was so helpful in keeping me focused and productive on those days where distractions would continually arise. I must thank my parents for always being there for the numerous phone calls and visits that helped me stay grounded, focused and happy. Your love and compassion kept me going. I am eternally grateful for my sisters’ love, guidance, generosity, and encouragement that have kept my dry in the greatest of storms. I thank all those who played their part... In helping me to play with sharks... I really had fun... And struggled a ton... And am proud to have made my mark. LIST OF TABLES Table 1. Blood and plasma state of sandbar sharks at experimental salinities. The values of the given concentrations of parameters measured from whole blood and plasma for C. plumbeus. All values are given as means ±standard error of the mean (SEM). The asterisk denotes parameters whose model showed a significant linear trend as a result of salinity. Thepound sign denotes parameters whose model showed a significant quadratic trend. The letter A denotes parameters whose ANOVA test was significant. Significance was determined at the 95% (p<0.05) confidence level. All significance testing was done for plumbeusC. only. Numbers in brackets [ ] denote sample size. Table 2. Blood and plasma state of dusky sharks at experimental salinities. The values of the given concentrations of parameters measured from whole blood and plasma for C. obscurus. Values are given as means ±SEM. Bracketed numbers lj denote sample size. Table 3. Osmotic, ionic, and blood state of sandbar sharks at control salinities. The values of parameters measured from whole blood and plasma for C.plumbeus for the full strength control salinity. All values are given as means ±SEM. Numbers in brackets [] denote sample size. Table 4. Ratios calculated of osmo/iono-regulatory capabilities for elasmobranch species. Sandbars shark sodium ratio is not calculated, as no change was evident from 100-80% SW. Superscript e (c) represents values estimated from Cooper and Morris 1998a. Table 5. Regression table of measured variables in sharks subject to dilute salinities. Coefficient, standard error, t-value, p-value are presented. Significance was determined at the 95% (p<0.05) confidence level.
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