Investigating Juvenile White Shark Physiology and Spatiotemporal Behavior in Potential Nurseries in the Gulf of Maine
Advisor: Professor Diego Bernal
Committee Members:
- Megan Winton ( Atlantic White Shark Conservancy, Chatham, MA)
- Lauren Brewster (School of Marine Science and Technology, University of Massachusetts)
- Andy Danylchuk (Department of Environmental Conservation, University of Massachusetts, Amherst)
- Professor Robert Gegear(University of massachusetts, Dartmouth)
Abstract: White sharks (Carcharodon carcharias, Family Lamnidae) are a circumglobally distributed apex predator with historical aggregations off the coast of Australia, South Africa, the eastern North Pacific, and the western North Atlantic (WNA). In the WNA, white sharks are commonly found off coastal waters between the Southeast U.S. and Gulf of Maine (GoM). In general, the life history of this species (i.e., k-selected: late maturity, long gestation, few offspring, and prolonged longevity) makes them highly susceptible to fishing pressure. Within the WNA, young-of-the-year (YOY), juvenile, and adult white sharks exhibit spatiotemporal overlap, however, adult white sharks appear to have a more offshore distribution, occupy colder temperatures and have more extensive vertical (i.e., depth) movements. For YOY and juvenile white sharks, recent work has suggested the presence of a nursery habitat in the New York Bight with recent observations suggesting an increased presence of juvenile white sharks in Maine’s coastal habitats. White sharks have the capacity to elevate their core body temperature above ambient via the retention of heat from counter current heat exchangers, allowing for a potential expansion into colder habitats. With ongoing ocean warming at an extreme rate in the GoM, understanding the thermal biology of juvenile white sharks will give insight into how their home range may be shifting northward (i.e., home range expansion), with the presence of a potential nursery habitat in the GoM. To investigate this hypothesis, a tag package containing a video, depth, activity, and several temperature loggers will be deployed on juvenile white sharks caught utilizing land-based shark fishing methods off Maine’s coastline. A long-term acoustic transmitter and short term satellite tag will be deployed in tandem to the tag package to determine the individuals geolocation. This study will increase our knowledge on the roles the GoM may play for successful juvenile white shark development in the WNA and how this species can be better managed/regulated in developing land-based shark fisheries.
SENG - 113
Professor Diego Bernal
508 999-8307
dbernal@umassd.edu