Dani Bartz, a PhD candidate in the Marine Biology Graduate Program at the University of Hawaiʻi at Mānoa, earned the first place award for Best Early Career Researcher Talk at the 2nd Australian and New Zealand Environmental DNA Conference. The conference, hosted by the Southern eDNA Society, took place in Wellington, New Zealand in February 2025.
Bartz’s presentation, “Testing the Waters: An Interdisciplinary Assessment of Current and Historical Shark Nursery Habitat in Hilo Bay, Hawaiʻi,” impressed the judges with its innovative approach to studying shark populations using environmental DNA and local ecological knowledge.
“It was an incredible honor to receive this award and represent UH Mānoa on an international stage,” Bartz said. “This recognition validates the hard work and interdisciplinary approach we’ve taken to understand and protect these vital shark nursery habitats.”
Tracking baby sharks
Juvenile sharks are often born and spend the first few years of life in shallow coastal areas called estuaries. These areas are changing a lot due to human activity, but scientists don’t have much data on how these changes are affecting the sharks. To make matters worse, it’s difficult to track sharks because they can be difficult to find, they move around a lot, and traditional tracking methods are expensive and not always ideal for newborn sharks due to their high sensitivity to capture stress.
The study by Bartz et al. set out to understand how juvenile sharks have used Hilo Bay as a nursery habitat throughout time, relying on local ecological knowledge from fishers and community members to reconstruct a baseline estimate of shark populations for the last 75 years. To better understand the contemporary situation of sharks in Hilo Bay, the study also employed a method called environmental DNA, where seawater was passed through filter papers and then these filters were sent to a lab for shark DNA to be extracted off of them. Local knowledge showed that there are fewer juvenile scalloped hammerhead sharks now than in the past, a critically endangered species, and more blacktip sharks.
To make this environmental DNA testing work well with the unique characteristics of Hilo Bay, Bartz spent more than a year testing different methods around Hawaiʻi and developed a novel filtration device to combat the issues of high turbidity, freshwater influx and variable shark population numbers in Hilo Bay. This approach allows scientists to monitor shark populations with minimally-invasive methods, providing crucial data for conservation efforts.
Bartz’s eDNA filtration system research was also developed through UH’s Patents2Products program, aimed at translating innovative ideas into commercial opportunities.
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Bartz, who is a member of the U.S. Geological Survey Hawaiʻi Cooperative Fishery Research Unit in Hilo, is supported by Timothy Grabowski from the UH Mānoa Marine Biology Graduate Program, and Alyssa Budd from the Commonwealth Scientific and Industrial Research Organisation, Perth, Australia.
