A portion of this research is funded by proceeds from Florida's Protect Wild Dolphins specialty license plate.
The Population Biology & Behavioral Ecology program’s state-of-the-art Ancient DNA Laboratory is a three-chambered clean room designed specifically for DNA/RNA extractions from samples of limited quantity whose quality has often been compromised by the passage of time and exposure to the elements. Our initial project focus is the extinct Steller sea cow, a giant sirenian that plied the frigid waters of the Commander Islands to the west of the Aleutian chain in the North Pacific Ocean. Discovered in 1742 by Vitus Bering’s expedition, the gentle leviathans were hunted to extinction within a few decades. We are collaborating with Russian colleague Dr. Alexander Burdin to investigate the ecology and behavior of Steller sea cows using aDNA techniques. This includes looking for clues in the DNA that may explain why the Steller sea cow population was small and its range -- from the time of first Russian contact to its demise -- very restricted. What we learn may be applicable to similarly small and restricted populations of marine mammals today.
Established in 2011, the Harbor Branch Ancient DNA Laboratory expands our ability to investigate the population biology, genetic diversity and species composition of past ecosystems. The facility is designed to accommodate several projects simultaneously, and since opening has yielded new insights into areas including the genetic causes of Steller sea cow extinction and biodiversity in marine systems during the neoglacial period, some 3,000 years BP.
Genetic studies by the Population Biology & Behavioral Ecology program span a diverse range: from dispersal patterns and population structures of beluga whales across the Arctic to community and group structures of bottlenose dolphins in estuarine systems in Florida, and from colonization and mating systems in Steller sea lions in the north Pacific Ocean to the demographic history and population structure of harbor seals in Alaska. We use numerous types of markers, tools and methods including mitochondrial DNA, microsatellite loci and MHC genes, high-throughput sequencing and genotyping and the latest likelihood and coalescent methods to infer demographic history, as well as past and contemporary patterns of behavior and life history. Much of our research is applied, assisting in resolving management of stocks of marine mammals and investigating possible genetic explanations for the failure of depleted populations to recover despite the implementation of robust protection and conservation measures.
Population biology, behavioral ecology and genetic structure of estuarine bottlenose dolphins
Estuarine systems are among the most dynamic and biodiverse aquatic systems. Their shores are often centers of urban development and their waters the terminus of rivers and canals. As such, estuaries bear the brunt of anthropogenic (man-made) activities both urban and rural. As these ecosystems struggle to adapt to increasing anthropogenic threats, climate change and other ecosystem-wide impacts so too do their apex predators. In the Indian River Lagoon, we are using a diverse array of research technologies, including molecular genetics, telemetry, acoustic monitoring and GIS to estimate population abundance, gene flow, dispersal patterns and stock ID. We investigate the genetics of individual and population health, fitness and viability, and learn about group structure, predator-prey interactions and foraging ecology.
A radio tracking study of bottlenose dolphins in the Indian River Lagoon, Florida was conducted in collaboration with HUBBS Sea World Research Institute during the summer of 2010. Dolphins were chosen based on known individuals within the HBOI Photo-Identification catalogue that portrayed high sightability and local home ranges. All dolphins were observed immediately after release with no unusual behavioral observations noted. Tracking was conducted primarily by boat-based surveys but additional data were acquired via aerial surveys. Sixty-eight hours were spent on survey, tracking all four individuals over the three-month study period. All individuals were tracked within their respective known home ranges, but specific locations were predominantly in the shallows (>81%), off the track line from ongoing photo-identification studies. The shortest transmission duration was 36 days, and longest was 62 days. The tags are designed to fall off, and to date, all dolphins have been sighted without attached tags and appear to be in good health. Future tracking studies will focus on behavioral interactions, male coalitions, and on equipment and attachment placement.
Figure 1. – Radio tag attachment before release.
Figure 2. – Hole made from designed disassembly of radio tag (disregard roto tag mid fin).
Figure 3. – Migration of intact radio tag.