November 2019: Grace Casselberry: Getting to Know Buck Island’s Sharks

During her talk, “Getting to Know Buck Island’s Sharks”, Grace will be sharing her past research on shark movements and habitat use in and around Buck Island Reef National Monument, including how the sharks responded to Hurricane Maria in 2017. She will also share an update from the ongoing tiger shark expedition which explores tiger shark movements throughout St. Croix.

Shark populations in the Caribbean are dramatically lower than expected, but the US Virgin Islands (USVI) represent one of the last strongholds for shark populations. Despite this, sharks in the UVSI are understudied when compared to other regions. Tiger sharks are large, wide ranging apex predators, frequently found on coral reefs, and have been studied minimally in the Caribbean outside of The Bahamas. Their size makes them desirable in both the commercial fin trade and artisanal fisheries in the greater Caribbean. Studies of tiger shark movements using acoustic telemetry in St. Croix indicate that they are wide ranging, regularly moving outside of the region’s largest marine protected area, Buck Island Reef National Monument (BIRNM). The purpose of this study is to tag tiger sharks with real time transmitting satellite tags (model SPOT, Wildlife Computers), whose data collection is not geographically restricted, as well as acoustic transmitters to better understand tiger shark’s home range in St. Croix and quantify connectivity between BIRNM and areas open to fishing throughout the USVI and greater Caribbean. This information is essential for improved fisheries management in the USVI and greater Caribbean as we work to protect declining shark populations and imperiled coral reef ecosystems.

Grace Casselberry is marine ecologist and PhD student at the University of Massachusetts Amherst (UMass), where she studies the movements and migrations of multiple shark species in St. Croix and the Florida Keys. Originally from Pennsylvania, Grace’s interest in fish and marine life was fostered during summer vacations spent fishing and exploring tide pools with her parents and grandparents in Cape Cod, Massachusetts. She transitioned this childhood love into a passion driven career, earning a Bachelor of Science in Ecology and Evolutionary Biology with a Marine Biology minor from the University of Connecticut. After graduating, she moved to Florida where she studied shark nursery areas, including assisting with population assessments of endangered smalltooth sawfish in Everglades National Park. In 2015, she began her Master’s degree at UMass, working with Dr. Andy Danylchuk and Dr. Greg Skomal, studying the movements of lemon, nurse, Caribbean reef, and tiger sharks in Buck Island Reef National Monument. Broadly, Grace is interested in the intersection of marine animal movement, particularly elasmobranchs (sharks, skates, and rays) with fisheries management. She is currently in St. Croix to satellite tag tiger sharks on an expedition funded in part by the National Geographic Society.