NEWS

Researchers at the University of Hawaiʻi at Hilo came together to posthumously complete and publish work initiated by a former Pacific Islands Climate Adaptation Science Center (PI-CASC) Manager Climate Corps graduate scholar, Bryan Tonga. The paper, published in Marine Pollution Bulletin, provides the first water quality data for Pohnpei’s coastal waters. 

Originally from Pohnpei, an island nation in the Federated States of Micronesia, Tonga was a student at UH Hilo pursuing a master’s degree in marine science. 

“There was little water quality data for Pohnpei, and wastewater looked like it was a potential issue that hadn’t been documented with water quality measurements,” said Dr. Tracy Wiegner, UH Hilo marine science professor and faculty advisor.

Tonga’s project would address knowledge gaps and establish a baseline for future comparisons. The goal was to provide a comprehensive assessment of water quality related to sewage pollution in coastal water, identifying hotspots. The research would be informative to resource managers, helping to prioritize these areas and protect them from potential flooding or other effects of climate change.

Tonga interned for Pacific Internship Programs for Exploring Science on a long-term water quality project in Puakō on Hawaiʻi Island. He would take what he learned from that internship and do something similar for his project.

Through funding from the Louis Stokes Alliances for Minority Participation and PI-CASC, in the summers of 2018 and 2019, Tonga returned home to Pohnpei to conduct sampling at stations previously established by the Pohnpei Environmental Protection Agency (EPA). He collected water and algae samples from 31 stations around the island’s coastline, including difficult-to-reach areas dominated by mangroves, taking readings of Nitrogen-15, which has very specific values for human sewage. 

“I think once he got to Pohnpei and began working with the EPA, the project really became his own – something he was proud of,” Wiegner recalls. “I don’t think he could have ever imagined the potential for how his work might be used. I didn’t either.”

He worked in concert with many agencies in Pohnpei for this study. In addition to scientists and natural resource managers from the EPA, Tonga also partnered with the National Food Safety Laboratory, the Conservation Society of Pohnpei, and the Natural Resource Conservation Service. These agencies provided lab space, granted use of equipment, and helped access sampling sites. 

In 2020, with the project three-quarters completed, Tonga tragically passed away in a hiking accident. To honor him, Tonga’s UH Hilo faculty advisors, Drs. Tracy Wiegner and Karla McDermid, committee member, Dr. Steve Colbert, and fellow student Devon Aguiar came together to finish what he started. It was recently published with Tonga as the lead author. 

“We felt it was important to publish Bryan’s work because his data set was novel,” explained Wiegner. “Prior to Bryan’s work, there was almost no water quality data for the nearshore waters of Pohnpei. As we were working on writing the manuscript and reaching out to folks in Pohnpei, we learned how timely his work was. Several groups in Pohnpei have formed a working group to address wastewater issues in Pohnpei, and Bryan’s data will help inform their work. This provided the final impetus for us to finish the manuscript so we could share the data with folks who would be using it to make decisions.”

The paper provides the first baseline water quality data for Pohnpei’s coastal waters since the 1980s and identifies land-based pollution sources, such as piggeries and dredging sites. The results from the study will be used to inform management actions to improve water quality.