HUMAN IMPACT ON QUEEN CONCH POPULATION DENSITY by Shelbey Rogers A Thesis Submitted to the Faculty of The Wilkes Honors College in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts in Liberal Arts and Sciences with a Concentration in Marine Biology Wilkes Honors College of Florida Atlantic University Jupiter, FL May 2019 HUMAN IMPACT ON QUEEN CONCH POPULATION DENSITY by Shelbey Rogers This thesis was prepared under the direction of the candidate’s thesis advisor, Dr. Jon Moore, and has been approved by the members of her/his supervisory committee. It was submitted to the faculty of The Honors College and was accepted in partial fulfillment of the requirements for the degree of Bachelor of Science in Liberal Arts and Sciences. SUPERVISORY COMMITTEE: ____________________________ Dr. Jon Moore ____________________________ Dr. William O’Brien ______________________________ Dean Ellen Goldey, Wilkes Honors College ii ACKNOWLEDGEMENTS A special thank you goes to Dr. Moore for being an incredible thesis advisor as well as Dr. O’Brien for being my second reader. A special thank you also goes to Dr. Wetterer for providing insight and guidance for my thesis during our Field Biology class. I would also like to thank the staff and faculty at the Harriet L. Wilkes Honors College for providing four years of fantastic experiences that would not have been available on any other campus. I would like to thank my great-grandmother Margie for sharing with me her love of the ocean and culturing an appreciation for zoological sciences. I would also like to thank Morgan Schad, Arielle Routledge, Stephanie Brinez, and Edwin Velasquez for providing a helping hand and assisting me in the field during the research portion of my thesis. iii ABSTRACT Author: Shelbey Rogers Title: Human Impact on Queen Conch Population Density Institution: Wilkes Honors College of Florida Atlantic University Thesis Advisor: Dr. Jon Moore Degree: Bachelor of Arts in Liberal Arts and Sciences Concentration: Marine Biology Year: 2019 Queen Conch, Lobatus gigas, is considered a threatened species that is native to the Caribbean and Gulf region, including South Florida. This thesis examines Queen Conch population density as affected by human activity in several areas along Florida’s East coast. Areas that are heavily trafficked by humans have shown a sharp decline in Queen Conch presence. Spot surveys were completed by the author in Tequesta, Boca, and Deerfield Beach. Community surveys published by Florida Fish and Wildlife were completed in The Florida Keys. Results showed a decrease in Queen Conch population numbers in areas heavily trafficked by humans. iv TABLE OF CONTENTS Section Page Number Introduction………………………………………………………………………..1-4 Materials and Methods…………………………………………………………….4-9 Results……………………………………………………………………………..10-12 Discussion…………………………………………………………………………12-15 Bibliography……………………………………………………………………….16-18 v LIST OF TABLES AND ILLUSTRATIONS Figure A-1 shows an overhead view of the Tequesta site. The yellow line shows the length of the site and the red line shows the width. Image was created with the help of Google Maps……………………….……………..….5 Figure A-2 & A-3 shows one of several Queen Conch aggregations that were found at the Tequesta Site on March 2 nd, 2018. Figure A-3 shows Queen Conch moving further apart as the high tide comes in. Pictures were taken by Shelbey Rogers…………………………………………………………………..6 Figure A-4 displays the paths walked along the Boca Raton site for the spot surveys. A1 and A2 are both two different starting points, while B1 and B2 are two different end points. Image was created with the help of Google Maps……………………………………………………………………………..7 Figure A-5 displays the paths walked along the Deerfield Beach site for the spot surveys. A1 and A2 are both two different starting points, while B1 and B2 are two different end points. Image was created with the help of Google Maps……..……………………………………………………………………….8 Figure A-6 depicts every site that Queen Conch were counted at across the Florida Keys in 2017 and was created by Florida Fish and Wildlife (FWCC 2017)…………………………………………………..………………………….9 Figure A-7 displays the number of Queen Conch counted at the Tequesta site as well as the size class they fell into………………………………………...10 Figure A-8. Each orange spot indicates the estimated population of adult Queen Conch found at each site that was indicated in Figure A-6. Figure from FWCC (2017)..…………………………………………………………………..11 Figure A-9. Each orange spot indicates the estimated population of juvenile Queen Conch found at each site that was indicated in Figure A-6. Figure from FWCC (2017).…………………………………….………………………..11 Figure A-10 Each orange spot indicates the total estimated population of Queen Conch found at each site that was indicated in Figure A-6. Figure from FWCC (2017)………………………………………………………………..……12 Figure A-11. Each orange spot indicates the total estimated population of Queen Conch found at each site that was indicated in Figure A-6. Figure from FWC (2017)…….…………………………………………………………..12 vi INTRODUCTION In 1992, the Queen Conch (scientific name Lobatus gigas) was officially listed under Appendix II of CITES international trade agreement, meaning it was recognized as a threatened species that would soon become endangered if there was not a quick reduction in overfishing (NOAA, 2014). Commercial fisheries for Queen Conch in the state of Florida had already been closed since 1975; and in 1986, a research program dedicated to monitoring the recovery of the species was started (Glazer, 2001). The Queen Conch is a large marine mollusk that lives inside a pink or orange shell that is made of calcium carbonate (Kreipl et al., 2011) and has a life span of up to thirty years (NOAA, 2014). Their age of reproductive maturity is reached at three, or four years depending on the resources available to them during their maturation process (Stoner et al., 2012). Juvenile Queen Conch living in a nutrient rich environment will have to spend less energy on securing resources and will be able to use that energy instead to develop their shells. Seagrass beds and sand flats are the habitats most associated with Queen Conch. Here, they feed on seagrass detritus and serve as an important part of the overall trophic structure in seagrass beds (Stoner, 1989). They serve as important prey to other mollusks and marine reptiles (Jory and Iversen, 1983) and their empty shells are often repurposed by hermit crabs (Berg, 1975). Queen Conchs are native to the tropical waters of the Caribbean, the Gulf of Mexico, and South Florida (NOAA, 2014). It is here that they have been one of the most important human food staples since the pre-Columbus era of the Caribbean (Stoner et al., 1 2018). This means it has been engrained into many of the native cultures of this region, and its importance has been passed down throughout generations—making the value of the Queen Conch cultural and economic. Their importance to the Bahamas, for instance, has contributed to the need for government-sanctioned Marine Protected Areas, but there is growing evidence that these areas are not helping the overall population as previously planned (Tan, 2018). Unfortunately, the Bahamas are not the only place witnessing the significant decrease of its Queen Conch populations. Countries throughout the Caribbean have suffered similar losses (Peel and Aranda, 2003). Conch meat used to be harvested in South Florida at twenty-thousand to fifty- thousand pounds per year in the mid-1960s (Kumazawa, 1980). The harvests decreased significantly by the early 1970s, suggesting that the populations of Queen Conch that were previously an abundant staple in Florida were diminishing (Kumazawa, 1980). For something that is so important to the culture, economy, and environment of several countries, there should be greater motivation to protect and ensure the survival of the Queen Conch. In 2001, a study was conducted by the Florida Marine Research Institute in conjunction with a NOAA partner and the Caribbean Marine Research Center (Glazer, 2001). The purpose of the study was to compare the recovery of Queen Conch in the United States with populations of Queen Conch in the Bahamas where the species is still heavily fished. What they found was the Bahamas still had higher population counts and the reason they concluded for this was the availability of larval Queen Conch. 2 A study that yielded similar results was done in the Marine Protected Area in Exuma Cay in the Bahamas. Despite the no-fishing policy established in these areas, there was a 71% recorded decline in adult Queen Conch populations (Kough et al., 2017). The decline in population supports the hypothesis that local Queen Conch populations are supported by larval recruitments from the metapopulation of Queen Conch in the Bahamas. As long as overfishing of the general population continues, local populations will continue to suffer with it. This research lead to a new experiment: raising Queen Conch in hatcheries and releasing them as juveniles with a better chance of survival (Glazer, 2001). This initiative was inspired by successful aquaculture work that was already done in the Turks and Caicos (Davis et al., 1987). There are several more issues contributing to Queen Conch decline other than overfishing. Despite their official status as threatened, there has been a serious lack of enforcement of CITES fishing laws that lead to illegal fishing and trade (Theile, 2001). Poaching is not a strange concept to conservation work (Actman, 2019), but there still seems to be a lack of initiative or will when it comes to stemming the impact. There is also the issue of biases in the industry that can further harm Queen Conch population stability under the guise of management. For example, the minimum shell length for legal fishing in Belize is 17.8cm (Strasdine, 1988). This is a reproductive maturity minimum. However, most scholars in the area would agree that shell length is an inappropriate measure for adult conch (Wood and Olsen, 1983).