A tale of three sharks
David is using genetics to better understand three of Florida’s sharks. By comparing the status of blacktip, great hammerhead and nurse shark populations, he hopes to learn about how these iconic animals are faring.
David Shiffman
Although I grew up far from the ocean in Pittsburgh, Pennsylvania, I’ve been interested in sharks for as long as my family can remember. I loved sitting by the shark tank at Pittsburgh Zoo and I read every book about sharks that I could get my hands on. As soon as I was old enough, I learned to scuba-dive and got my certificate. I then spent five summers at the marine biology summer camp SeaCamp in the Florida Keys. Now I’m a graduate student at the University of Miami studying shark ecology and conservation and, between my research and my...
An assessment of the population status of coastal shark species in Florida using molecular tools
The goal of this project is to use molecular tools to determine the population status of three coastal shark species facing varying levels of fishing pressure in Florida, and to compare the population status of one species across management regimes.
Assessing the severity of declines and the degree of recoveries in shark populations has been identified as a research priority to help guide their conservation and management.
Over the past two decades, multiple independent research methods have identified severe and rapid population declines in many shark species. There have been significant efforts to reverse these declines and foster population recovery through implementation of various conservation policies. However, empirical evidence evaluating the efficacy of these policies is limited. Molecular tools offer a new avenue for assessing such policies.
The three species we have chosen to study have varying degrees of fisheries exploitation in the Florida Keys and throughout their range. Nurse sharks are not commercially exploited and their populations are thought to be high in coastal Florida. Blacktip sharks are commercially exploited, whereas great hammerhead sharks are thought to have declined severely due to by-catch and targeted fisheries. In recent years, the population trends of these species in areas where fishing has been restricted remains unknown. Samples have already been collected and microsatellite markers developed for each species.
The aims and objectives of this project are to:
- Determine whether blacktip, great hammerhead and nurse shark populations in coastal Florida have changed in recent decades and between areas with variable levels of protection.
- Determine if population trends vary by the characteristics associated with each shark species, including life history traits and the rate of exploitation by fishers.
- Determine if population trends vary among species and between locations with different management regimes.