Study shows rising mercury levels in Hawaiian yellowfin tuna

New science on one of Hawaii's favorite foods: Hawaiian yellowfin tuna. The study says that ahi species contains a potent toxin that's on the rise.

A separate 2011 study found the average Hawaii household eats four pounds of ahi poke per year.

It might be even more than that this season as fishermen have been reeling in huge catches causing ahi prices to drop.

As ahi prices are plunging statewide, researchers say they finally have the data to prove what they've suspected for years: that mercury levels are increasing in Hawaiian yellowfin tuna, rising about four percent a year.

"Shouldn't necessarily prevent people from eating it on a day to day basis, but people should be worried about what the future will bring," said co-author of the report Dr. Carl Lamborg with the University of California at Santa Cruz.

The scientists from California and Michigan blame emissions from coal-fired power plants and a surge in small gold mining operations that flush mercury into the ocean.

The owner of Alicia's Market in Kalihi says he doesn't think his sales will suffer.

"It won't stop them from eating poke overall. I'm sure they'll probably buy half pound instead of one pound and probably eat every other day instead of every day," said Leonard Kam.

Ahi lover Vangie Tolete says the study concerns her.

"It stops me in the way that if it's really affecting my health, then I guess we have to kinda cut down,” she said.

Even before this study,

already listed yellowfin tuna as a “high mercury” species, recommending no more than three servings a month.

It's still not as high as swordfish and marlin, which pregnant women are warned not to eat.

But the rise is a concern because the toxin can affect development of the central nervous system for fetuses and children.

"Fish of course is very healthy food, so it's not something we want to cut out of our diets entirely. But it might be something you want to think about decreasing," said Dr. Lamborg.

Fish not so high in mercury include butterfish, trout and salmon.

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