Montclair State University Montclair State University Digital Commons Theses, Dissertations and Culminating Projects 5-2017 Risks Associated with Harvesting and Human Consumption of Two Turtle Species in New Jersey Natalie R. Sherwood Montclair State University Follow this and additional works at: https://digitalcommons.montclair.edu/etd Part of the Environmental Sciences Commons Recommended Citation Sherwood, Natalie R., "Risks Associated with Harvesting and Human Consumption of Two Turtle Species in New Jersey" (2017). Theses, Dissertations and Culminating Projects. 46. https://digitalcommons.montclair.edu/etd/46 This Dissertation is brought to you for free and open access by Montclair State University Digital Commons. It has been accepted for inclusion in Theses, Dissertations and Culminating Projects by an authorized administrator of Montclair State University Digital Commons. For more information, please contact [email protected]. RISKS ASSOCIATED WITH HARVESTING AND HUMAN CONSUMPTION OF TWO TURTLE SPECIES IN NEW JERSEY A DISSERTATION Submitted to the Faculty of Montclair State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy by NATALIE R. SHERWOOD Montclair State University Upper Montclair, NJ 2017 Dissertation Chair: Dr. Meiyin Wu Copyright © 2017 by Natalie R. Sherwood. All rights reserved. ABSTRACT RISKS ASSOCIATED WITH HUMAN CONSUMPTION AND HARVESTING OF TWO TURTLE SPECIES IN NEW JERSEY by Natalie R. Sherwood Snapping turtles and diamondback terrapins have unique life characteristics, making their populations’ survivorship heavily dependent upon the turtles that reach sexual maturity, limiting the harvest potential of turtles and making them vulnerable to exploitation. Therefore, this research tests mercury concentrations in diamondback terrapins and snapping turtles to determine if turtle meat should require human consumption advisories, and examines transport of mercury through the snapping turtle food web by testing prey items for mercury burden and mapping food webs using stable isotope composition. Consumption of New Jersey diamondback terrapins and snapping turtles pose a health risk. 25% of Cape May and 46% of Meadowlands terrapin muscle samples surpassed the U.S. Environmental Protection Agency mercury threshold for fish consumption. For snapping turtles, Lake Wapalanne had the highest percent of turtle samples surpassing the threshold (36%), followed by Kearny Freshwater Marsh (33%) and Lake Hopatcong (28%). Based on the results of this study it is crucial to implement human consumption advisories for consumed turtle species. Neither the commercial or recreational harvest of snapping turtles in New Jersey is well understood. We therefore administered a survey to learn about current harvest iv practices, willingness of commercial and recreational harvesters to pay increased license fees, and their willingness to comply with new regulations. Respondents to the recreational harvest survey collected approximately 2,285 snapping turtles between 2012 and 2014. Respondents from the commercial harvesting survey reported collecting 1,506 turtles during the 2014 season. Commercial harvesters are willing to pay a higher permit price, up to $29.22, to keep their harvesting privileges. The results of this study suggest diamondback terrapin and snapping turtles pose a human consumption health risk due to elevated mercury concentrations. We suggest consumption advisories be developed for snapping turtles starting with locations of heavy harvest while advising the sensitive population to avoid the consumption of turtles. Based on the results of the harvest surveys we can suggest both recreational and commercial harvesters are willing to follow regulations in order to ensure future harvest. Harvesters are also willing to pay a higher permit price to keep their current harvesting privileges. v Acknowledgments The journey to the completion of this dissertation is owed to the many special people who provided their constant support and guidance. I would like to express my deepest gratitude to my advisor, Dr. Meiyin Wu, whose expertise, guidance, and support through my entire graduate education made this dissertation possible. I would also like to extend my most sincere gratitude to my committee Dr. Pankaj Lal, Dr. Peddrick Weis, Mr. Eric Stern and Dr. Stephanie Brachfeld for their constant encouragement and guidance. I would also like to thank, Brian Zarate for teaching me everything I know about turtles. Lisa Barno and the New Jersey Division of Fish and Wildlife for their constant support, which made this study possible. I am also extremely grateful to Dr. Michael Weinstein for his knowledge and assistance throughout this study. I would also like to extend a very special thanks to The Wetland Institute, Dr.’s Robert Wood, Patrick Baker, and Ralph Werner for providing terrapin specimens and showing me how to handle my first snapping turtle. Brett Bragin from the New Jersey Meadowlands Commission for always keeping a look out for any unfortunate road kill and providing terrapin specimens. I am highly indebted and grateful to Dr.’s Bill Thomas and Randy Fitzgerald, and everyone at the School of Conservation for assisting me throughout the years in site access and trap monitoring. I would not have been able to get the amount of the data I did without your constant support. Laurie Murphy and the Dow’s Boat Rental crew for all their help and assistance with trapping at Lake Hopatcong. vi I am extremely thankful to all my fellow graduate friends specially Kelly Triece for always helping me in the field and sharing the excitement of turtle trapping and handling. Pralhad Burli for your assistance in statistical analysis and Yaritza Acosta for your macroinvertebrate identification expertise. Lastly, and most importantly, I would like to thank my family and puppies for their constant understanding, love, and support especially during these last couple months as we also prepared for the arrival of our first baby. I would not have been able to complete this journey without you. vii Table of Contents Chapter 1. Turtle Life History, Threats, and Conservation ......................................... 1 1.1 Introduction ................................................................................................................. 1 1.2 Snapping Turtles (Chelydra serpentina) .................................................................... 2 1.2.1 Habitat and Distribution ............................................................................................. 4 1.2.2 Life History Characteristics ....................................................................................... 6 1.2.3 Status of the Common Snapping Turtle ..................................................................... 8 1.2.4 Human Impact on Snapping Turtles .......................................................................... 8 1.2.5 Snapping Turtle Harvest ............................................................................................ 9 1.2.6 Snapping Turtle Harvest in New Jersey................................................................... 16 1.3 Diamondback Terrapin (Malaclemys terrapin) ...................................................... 20 1.3.1 Habitat and Distribution ........................................................................................... 20 1.3.2 Life History Characteristics ..................................................................................... 21 1.3.3 Status of the Diamondback Terrapin ....................................................................... 22 1.3.4 Human Impact on Diamondback Terrapins ............................................................. 23 1.3.5 Diamondback Terrapins Harvest ............................................................................. 24 1.3.6 Diamondback Terrapin Harvest in New Jersey ....................................................... 25 1.4 Mercury ..................................................................................................................... 25 1.4.1 Mercury Behavior and Pathways in the Physical Environment............................... 27 1.4.2 Mercury in the Aquatic Food Web .......................................................................... 28 1.4.3 Mercury Concentration in a Snapping Turtle Food webs ........................................ 31 1.4.4 Human Health Risks ................................................................................................ 32 1.5. Stable Isotope Analysis ............................................................................................ 34 1.6 Research Objectives .................................................................................................. 36 1.7 Literature Cited ........................................................................................................ 38 Chapter 2. Human Health Implications of Mercury Concentrations in Diamondback Terrapins ......................................................................................................................... 51 2.1 Abstract ...................................................................................................................... 51 2.2 Introduction ............................................................................................................... 52 viii 2.2.1 Human Health Risk .................................................................................................. 53 2.2.2