Caribbean connections

  • Sharks
Years funded
  • 2023, 2024
  • Active
Project type
  • Research

Steven and Kevin are using genetic techniques to understand how Caribbean reef shark populations are connected across the extent of their range. Populations of this Endangered shark are in decline generally, but where they are managed and there is effective protection, their numbers are stable. With the integration of the correct information, Steven and Kevin are convinced that we can give Caribbean reef sharks a better shot at recovery and population stabilisation. They will also explore any barriers to connectivity, looking to the future recruitment and recovery of these sharks.

Caribbean connections

Steven Kessel

Project leader
About the project leader

Dr Steven Kessel gained his PhD in marine ecology and biology from Cardiff University, UK, conducting his field work at the Bimini Biological Field Station in The Bahamas. Following the completion of his degree in 2009, he spent two years at Cardiff University as a postdoctoral fellow, acting as the principal investigator for the Jupiter Large Coastal Shark Species Study, which investigated the biology and ecology of large coastal shark species resident off the eastern seaboard of the USA. Since then, Steven has worked for the University of Windsor Great Lakes Institute for Environmental Research as the principal...

Caribbean connections

Kevin Feldheim

Project leader
About the project leader

Dr Kevin Feldheim received his PhD in 2002 from the University of Illinois at Chicago. He has been working at the Field Museum in Chicago as the A. Watson Armour III manager of the Pritzker Laboratory for Molecular Systematic and Evolution since 2001. His work entails using genetic markers to examine the mating system and population genetics of elasmobranchs. One of his main projects is leading the genetic studies of lemon sharks from Bimini. This project encompasses a 25-year sampling period that has provided insight into several aspects of elasmobranch mating biology.

PROJECT LOCATION : United States of America
Related Blogs
By Steven Kessel and Kevin Feldheim, 16th May 2024
The Necessity of Adaptability: A Fieldwork Story
A critical part of fieldwork is adapting to conditions well beyond your control. Our most recent shark-focused research trip to the field, which involved Shedd Aquarium, Field Museum, and American Shark Conservancy, was no exception. Our initial plans were to set Baited Remote Underwater Videos…
By Steven Kessel and Kevin Feldheim, 6th February 2024
A Day in the Life of a Shark Conservation Genetics Intern
Have you ever wondered how DNA is extracted from shark fin clips for genetic sequencing? Well, join Karen Figueroa, a project intern at the John G. Shedd Aquarium and Field Museum of Natural History, and your guide to the mesmerizing process of extracting DNA from…
By Karen Figueroa, 29th November 2023
Conservation genetics can help unravel the mysteries of the Caribbean reef shark
Over the past year, hundreds of genetic samples have made their way from warm Caribbean waters to the frigid Midwest and now reside in freezers at Chicago’s Field Museum of Natural History where they await genetic analysis. More than 700 fin clips from the Caribbean…
By Dr. Steve Kessel, Director of Marine Research at Shedd Aquarium, 5th July 2023
Out of the darkness and into the light
Scientific discovery gives a new purpose to archived genetic samples. Tucked away in the overcrowded fridges and freezers of shark researchers around the globe sits a treasure trove of genetic data, just waiting to be analyzed. Over decades of field research, scientists have collected and…
Project details

Examining population structure at multiple scales in the endangered Caribbean reef shark

Key objective

To describe the population connectivity of the Endangered Caribbean reef shark at both fine and large scales throughout its range and to inform the development of effective conservation management to ensure the species’ survival and recovery.

Why is this important

In 2021, the Caribbean reef shark was designated Endangered on the IUCN Red List, with the overall population found to be decreasing. Targeted and caught as bycatch in areas without protection, populations have declined by up to 99% over the past three generations. Where effective protection measures exist, however, populations have remained stable since the 1980s, demonstrating the potential for stabilising decreasing populations and promoting recovery by implementing appropriate conservation measures.


The Caribbean reef shark Carcharhinus perezi is a Carcharhiniform that grows to about three metres (10 feet) in total length and functions as a key mid- to upper-level predator in coral reef ecosystems through the tropical and subtropical western Atlantic. Abundant on healthy reefs, it is considered to have a strong controlling influence on ecosystem balance and health. In addition to its value in maintaining ecosystem health, it has a high ecotourism value as one of the most common species associated with shark dive tourism in the Caribbean region, particularly in The Bahamas. Unfortunately, it is also valued for its meat, fins, skin (leather), liver (oil) and carcass (fishmeal) and in many areas has been commercially exploited and taken as bycatch in gill-net and longline fisheries. In areas without protection, Caribbean reef shark populations have declined by up to 99% over the past three generations (about 29 years). This led to the species being classified as Endangered on the IUCN Red List in 2021, highlighting the need for increased conservation management intervention to ensure its persistence and recovery. A growing body of literature provides important life history, spatial ecology and regional abundance data, but a critical missing piece of the puzzle is an extensive analysis of population genetics throughout the species’ known range. Many researchers in the field of shark science have been sampling Caribbean reef sharks and stockpiling tissue samples for future analysis. This project provides the opportunity for these samples to contribute to the shark’s long-term conservation. With the samples already committed, this would constitute the most geographically expansive (and collaborative) genetic investigation of the species – an investigation that would lead to a comprehensive understanding of population genetics throughout the Caribbean reef shark’s range in terms of variability, recruitment potential for depressed areas and effective population size.

Aims & objectives

The overall aim of the project – to describe the population connectivity of the Caribbean reef shark throughout its range as it relates to its conservation – will be achieved through the following objectives:

  • To secure genetic samples across the species’ range across potential barriers to connectivity. This will be achieved by leveraging the extensive research networks of both project leaders to secure samples that will provide an accurate representation of population variability.
  • To conduct next generation sequencing of samples to reveal genetic variability and connectivity across the species’ range. We will employ the 3RAD technique to develop thousands of SNPs to examine population genetics of this species.
  • To investigate potential barriers to connectivity, and therefore potential future recruitment for recovery, by modelling genetic results against physical parameters such as currents, bathymetry and habitat connectivity.