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.
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...
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:
John is developing a set of targeted ‘capture panels’ that focus DNA sequencing efforts on specific regions of the cownose ray genome that can be used to identify related individuals. These panels will facilitate construction of a close-kin mark-recapture model to estimate abundance of cownose rays along the US East Coast.
To find out which shark species occur in Puerto Rican waters, Glorimar is using genetics and getting samples from fish markets. She also relies on the assistance of local fishers. Filling this fundamental knowledge gap will help to assess local consumption of sharks and build up the community’s understanding of how sharks function in the marine ecosystem.
Working together with anglers in Florida, Jill and Hannah are trying to understand what the impact of catch-and-release recreational fishing is on Endangered great hammerhead sharks in Florida. Their findings will help draft better practices for the future.