One of the most pressing global conservation concerns is the loss of large predatory fish, especially sharks, from marine ecosystems. Despite the need for urgent action, very little is known about the spatial scaling, evolutionary dynamics and breeding biology of shark populations, which is necessary to develop effective management strategies. This study will expand a long-term analysis of the breeding biology of the lemon shark, and for the first time for any large marine vertebrate, examine the evolutionary dynamics of critical fitness traits (growth, early survival, condition factor) using a quantitative genetics approach. The investigators will build on previous research to (1) directly determine whether female lemon sharks return to their natal nursery for parturition (natal philopatry), (2) examine the lemon shark's mating system both locally and regionally at two separate nurseries (Bimini, Bahamas and Marquesas Key, Florida), (3) use quantitative genetics to understand heritability and local adaptation of fitness traits at these two sites, and (4) document genetic impacts of an anthropogenic disturbance at our main study site in the Bahamas. As a result of prior support, the necessary microsatellite markers are fully developed and over 2000 sharks have been sampled over ten years from these two populations.
The Broader Impacts Teaching and Training include three university courses given at the Bimini Biological Field Station and involving the ongoing research on elasmobranch fishes. As part of the investigators' work, students from around the world will be trained in both the field at Bimini and Marquesas Key as well as the laboratory in Chicago. Underrepresented Groups are targeted through a special privately funded program that brings for underprivileged high school students, Latino, Caribbean and African Americans, to the Bimini Biological Field Station annually. In addition to publishing results in peer-review journals and presenting at international meetings, our findings will be presented to the public in the upcoming Field Museum exhibit, "Pritzker Lab on the Floor." Results of this research will be used to suggest appropriate management schemes for lemon sharks in and around the Florida Keys and presented to the Bahamian government to assist in designating Bimini lagoon as a Marine Protected Area.
