Savannah Ryburn, Ph.D. student in the College of Arts and Sciences’ Environment, Ecology and Energy Program
Ryburn is creating a comprehensive assessment of the ecology and habitat of juvenile scalloped hammerhead sharks in the Galapagos. Little is known about this species of shark at the juvenile stage, including how long they reside in the nursery habitats, movement among nurseries, diet and why certain bays are chosen as nurseries.
The Tar Heel’s research uses satellite and identification tags to investigate the sharks’ movement, DNA analysis of shark fecal matter to describe their diet and measurements of environmental characteristics, such as water temperature and salinity, to characterize the nursery bays. From her data, she can determine what animals have been in the bay — essentially their menu of what is available to eat — and what the sharks are choosing to eat off of that menu.
“Shark nursery grounds often consist of coastal, protected bays and estuaries, which can be susceptible to increased pollution, tourism and fishing. Scalloped hammerhead sharks are critically endangered globally and have experienced dramatic declines in the eastern Pacific population. Therefore, it is essential to identify nursery grounds in the Galapagos that could potentially increase the resilience of adult populations and incorporate them into management plans throughout all life stages, not just as adults.
“The Galapagos are very important for my research because recently, a few scalloped hammerhead nursery grounds have been discovered throughout the archipelago. This species is iconic to the islands because they are known to school there in large numbers as adults. If we can increase their chance of survival as juveniles, we can hopefully aid in the recovery of their overall population.”
Above: Ryburn holds tubes that contain water filter papers that are used for extracting DNA samples from the water to study the habitat of juvenile scalloped hammerhead sharks.