All research conducted under A scientific permit issued by the Bahamas department of marine resources
Our understanding of the shark and ray fauna in Andros is limited, particularly information on those that reside in the pelagic ecozone of the Tongue of the Ocean. Further Andros is vast, with unexplored creeks and back-country that likely provide key nursery areas for many species. Delineating and describing these habitats and learning more about the biology and behavior of the animals that use them will contribute important data to conservation efforts, especially for species whose populations have experienced substantial declines, such as the smalltooth sawfish, oceanic white-tip, scalloped and great hammerhead sharks.
Our lead scientist, Dr. Tristan Guttridge has 14-years of experience conducting scientific research with sharks in the Bahamas, working as the director of the world-renowned Bimini ‘Sharklab’ for 6 years, before moving over to The Silent Hunter Group. He is skilled in a variety of techniques, from biotelemetry (acoustic and satellite tracking), to catch and release (via longlines and polyball fishing), semi-captive behavioral experiments, SCUBA diving with photo ID and laser-photogrammetry and both baited and non-baited remote underwater video surveillance (RUVs and BRUVs). More recently, he has pioneered a research project investigating the biology and behavior of the elusive and endangered great hammerhead shark.
Our team work alongside partner, and registered 501(c)(3) nonprofit Saving the Blue, whose vision is to recover and restore a variety of threatened marine species, while connecting people to ocean wildlife.
Evaluation of the elasmobranch community of Andros Island, Bahamas
Within the Bahamas, sharks and rays are protected from harvesting because of their value for ecotourism. Yet, across many of its islands, an ecological understanding of sharks and rays within the Bahamas is limited or absent because of logistical and resource constraints. As such, gaining insight into these economically and ecological valuable species is of great importance to support the Bahamas, as well as other countries striving to protect wildlife and essential habitat. The proposed research aims to describe the diversity, distribution, and resource use of sharks and rays in the waters surrounding Andros Island, the Bahamas, and how spatial and temporal variability in environmental conditions (e.g. water temperature) and habitat quality (e.g. coral cover) shape this ecological community. Our team capture and sample sharks and rays using a variety of techiniques to quantify presence/absence, abundance, and diversity, including gill nets, longlines, and snorkel surveys. During these we collect tissue samples from individuals for stable isotope analysis to quantify food resource use and overlap within and across species. Finally, we use acoustic and satellite tracking to assess patterns in habitat use, and short- and long-distance migrations. This research will provide invaluable information on community structure, essential habitat characteristics, and critical food sources for sharks and rays that serve important functional roles as predators within coastal food webs, as well as vital economic support for the Bahamas.
How will you contribute?
During expeditions guests will have the opportunity to contribute to our research projects, and will gain hands-on experience in deployment of gillnets and drumlines to capture and process various species of sharks.
Some of our teams research publications can be found below
Reviews/ Book Chapters
Gallagher AJ, Vianna GMS, Papastamatiou YP, Macdonald C, Guttridge TL, Hammerschlag N. 2015. Shark diving tourism: biological impacts, conservation benefit, and future research. Biological Conservation. 184: 365-379.
Finger JS, Dhellemmes F, Guttridge TL. 2017. Personality in elasmobranch fishes with a special focus on sharks: early evidence, challenges and future directions. Springer Volume. Personality in Non-Humans. Springer Nature. DOI: 10.1007/978-3-319-59300-5_7
Mourier J, Ledee E, Guttridge TL, Jacoby DMP. 2018. Network analysis and theory in shark ecology: methods and applications. Emerging Technologies and Application for the Study of Shark Biology. Eds: Jeff Carrier, Michael Heithaus, Colin Simpfendorfer. CRC Press. August 2018.
Hammerhead, Sphyrna mokarran
Guttridge TL, Van Zinnicq-Bergmann M, Bolte C, Howey-Jordan L, Kessel ST, Brooks J, Bond ME, Winram W, Jordan LK, Cashman R, Tolentino E, Grubbs RD, Gruber SH. 2017. Philopatry and regional connectivity in the great hammerhead shark, Sphyrna mokarran in the U.S. and Bahamas. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2017.00003.
Smalltooth sawfish, Pristis pectinata
Guttridge TL, Gulak S, Franks BR, Carlson J, Gruber SH, Gledhill KS, Bond ME, Johnson G, Grubbs RD. 2015. Occurrences and habitat use of the Critically Endangered smalltooth sawfish (Pristis pectinata) in the Bahamas. Journal of Fish Biology. 87: 1322-1341.