Some fish contain more mercury than others and UH researchers were part of team that recently discovered why.
The scientists found that sunlight determines the amount of mercury fish consume.
This is backed by previous research that fish that feed at deeper depths, like opah and swordfish, have higher levels of mercury than ones closer to the surface, like mahimahi and yellowfin tuna.
"That mercury must be converted by microbes to organic mercury. Our results show it is destroyed in surface waters," said Brian Popp, a professor of geophysics at the University of Hawaii.
Research also found most of toxic elements found in fish came from mercury that had been sent up in the atmosphere, through the burning of fossil fuels or other natural processes like wildfires or volcanic eruptions.
Now UH scientists want to investigate if those mercury levels in fish populations have changed over time.