There are 187000000000000 million gallons of water in the Pacific Ocean. The plant "leaks" (they're intentional) are not affecting Hawaii; they're not even affecting Japan's coast.
"In April 2014, studies confirmed the presence of radioactive tuna off the coasts of the pacific U.S.[228] Researchers carried out tests on 26 albacore tuna caught prior to the 2011 power plant disaster and those caught after. However, the amount of radioactivity is less than that found naturally in a single banana.[229][230]
As of June 2016, dispersed nuclear fallout and associated radiation contamination continue to pollute the environment. Tilman Ruff, a professor at the University of Melbourne, stated that every day 300 tons of contaminated water leak from the crippled nuclear plant.[231] The Reconstruction Agency states that 174,000 people have been unable to return to their homes. Ecological diversity has decreased and malformations have been found in trees, birds, and mammals.[231]"
300 tons is 80,000 gallons. The ocean is 187,000,000,000,000,000,000 gallons. And, it's not "less than a banana"; it's less than one twentieth of a banana.
We carpet bombed the oceans with nuclear weapons in the 1950s, which created tritium levels we can still track regionally today. Nobody thinks it's a great thing that Fukushima happened, but the water thing is probably not in the top 5 concerns.
