What’s in the Water? Ph.D. Student Studies the Organisms in Large Ships’ Ballast Tanks

Bill Gerhard

Ships fill and empty their ballast tanks as needed for stability. Whenever ballast water is taken on or discharged, aquatic plants and animals go along for the ride, which increases the risk of introducing invasive species.

William Gerhard is a Ph.D. student in Civil & Environmental Engineering. Recently he spent a month at the Danish Hydraulic Institute learning how to incorporate antibiotic resistance genes and pathogens into a global ballast water movement model. This experience will enhance his dissertation research on microbes in the ballast water of large ships, and Gerhard hopes this research will potentially inform policy and regulatory decisions under debate by the United Nations.

Gerhard was among 18 Duke University students who received Graduate Student Training Enhancement Grants (GSTEG) in 2017-18 from the Office of the Vice Provost for Interdisciplinary Studies for training beyond their core disciplines. His faculty mentor is Claudia Gunsch. He shared an update:

With funding from the Graduate Student Training Enhancement Grant, I travelled to Singapore for an internship with the Danish Hydraulic Institute (DHI). This company specializes in creating modelling software for hydrologic systems. In addition, DHI operates the only tropical ballast water testing facility in the world. My dissertation focuses on the microbial community of ballast water in large ships, so their expertise in ballast water and modelling proved especially informative to my ongoing work.

During my time at DHI, I was exposed to science and laboratory work in a corporate environment. I assisted their researchers in drafting and testing a protocol that could be used to assess whether their test microbes were representative of the microbes found in Singapore’s natural waters. This protocol is now being examined by other ballast water testing facilities worldwide with the possibility of future adoption to the standard protocol.

Outside of the lab, I was exposed to DHI modelling software, and I learned the best practices for its use from those who wrote the program. This experience was especially valuable as I had minimal experience using the model prior to my time in Singapore. I left with a strong grasp of the program after four weeks, and several contacts to whom I could reach out in the event of future troubles.

The unique opportunity afforded by GSTEG allowed me to explore a potential future career path while also expanding comfort zones within my dissertation research.


This internal funding mechanism from the Office of the Vice Provost for Interdisciplinary Studies encourages doctoral and master’s students to step away from their core research and training to acquire skills, knowledge, or co-curricular experiences that will give them new perspectives on their research agendas. Graduate Student Training Enhancement Grants are intended to deepen preparation for academic positions and other career trajectories.