A new study by University of Hawaii scientists found that Vibrio vulnificus, a “flesh-eating” bacteria that lives naturally in the water of the Ala Wai Canal, could triple in population there by the end of the century.

The team found that rainfall and rising water temperatures from climate change are major contributors to the organism’s growth.

“Something that people haven’t thought about a lot yet is the impact of climate change on coastal pathogens,” said the study’s lead author, Jessica Bullington.

Bullington was pursuing her master’s degree at UH Manoa’s School of Ocean and Earth Science and Technology at the time of the research and is now a doctoral student at Stanford University.

The research team worked with UH Strategic Monitoring and Resilience Training in the Ala Wai watershed, where at least 20 undergraduate students and six graduate students from SOEST gathered samples from the canal and processed them at the Daniel K. Inouye Center for Microbial Oceanography Research and Education, according to a UH news release.

“Our goal was to make a forecast of this pathogen so that people can check it like you would check the weather before you would go out, like if you’re gonna go surfing at Ala Moana, for instance,” Bullington said.

The team gathered samples monthly and documented which water conditions correlated with a higher abundance of V. vulnificus. In addition to monthly sampling, the researchers used oceanographic sensors that continuously monitored water quality at the mouth of the canal.

The team was able to use data from the Pacific Islands Ocean Observing System — which can track water temperature, salinity, currents and dissolved organic matter — to help predict bacteria abundance in the canal and harbor.

“The chemical makeup in the canal really kind of promotes the growth of this pathogen,” Bullington said. “It’s growing there naturally, so it’s not sewage-associated or anything. The Ala Wai Canal really acts to accumulate a lot of these chemicals that are … basically things that this pathogen eats.”

The water in the canal is a mixture of freshwater from nearby streams and runoff mixing with ocean water, creating a brackish-water environment that remains relatively stagnant.

“That’s the environment that this pathogen really, really likes,” Bullington said. “So I think inadvertently we kind of … man-engineered this system that is actually kind of an incubator for these bacteria.”

Rainfall also helps the pathogen thrive, researchers found.

Bullington said infections caused by V. vulnificus are relatively rare but warned swimmers to avoid the Ala Wai Canal and nearby waterways.

In 2006, 34-year-old Waikiki resident Oliver Johnson died after he fell into the Ala Wai Boat Harbor and contracted a V. vulnificus infection through open wounds. Just days earlier, heavy rains had caused a Waikiki sewer main to break, leading city officials to divert 48 million gallons of raw sewage into the canal.

Bullington said officials should explore mitigation measures such as putting oyster beds or plants in the canal to provide more balance to the environment while developing longer- term strategies.

“We should start mitigating now and coming up with strategies to sort of reduce the population (of the bacteria) or increase the circulation of the canal (and) kind of mitigate how much organic matter is sitting there — just doing something about it now so we don’t kick ourselves in the future,” she said.