A Seattle-based seafood company says independent testing has found “no indication” of radiation in their Puget Sound and Southeast Alaska salmon, even as two Alaska samples showed telltale “traces” linked to Japan’s Fukushima nuclear disaster.

The March 2011 partial nuclear reactor failures in Fukushima, Japan have been the focus of Food and Drug Administration monitoring—and public scrutiny—since the disaster happened. During the crisis, radioactive material was released into the Pacific Ocean, igniting concerns of ecosystem damage and Pacific seafood stocks.

The FDA said in a September update that there is “no evidence that radionuclides from the Fukushima incident are present in the U.S. food supply at levels that would pose a public health concern.”

But Loki Fish Co. owner Peter Knutson said costumers continued to voice concerns over possible radiation in Pacific fish. That pushed the company to act.

“What we did is go straight to an independent lab and got the analysis,” Knutson said. “Blowback” from customers “fueled by internet rumors” made paying for the tests “the ethical thing to do.”

Five samples of Alaska fish caught near Prince of Wales Island and “within 100 miles of” Ketchikan in July and August of 2013 were tested by an independent lab. The samples included king, sockeye, keta/chum, pink, and coho/silver salmon.

Samples of king and keta/chum salmon from Washington State’s Puget Sound were also tested.

Testing was done by Eurofins Analytical Laboratories in Metaire, Lousiana, and cost Loki Fish Co. “about $1,200,” Knutson said.

The tests looked for three radionuclides associated with the nuclear reactor failures: Cesium 134, Cesium 137, and Iodine 131. Levels of radiation are measured in becquerels per kilogram (Bq/kg), a standard unit of radioactivity measuring “the number of particles decaying per second in each kilogram of a sample,” according to the U.C. Berkeley Department of Nuclear Engineering.

Five of the seven samples had no detectable levels of any of the three radionuclides tested, measuring below 1 Bq/kg.

Two Alaska samples were found to have “trace levels” of radionuclides: Alaska keta/chum salmon registered 1.4 Bq/kg for Cesium 137, while the sample of Alaska pink salmon measured 1.2 Bq/kg.

“Those two samples registered something barely above normal,” Knutson said. “We’re at background levels that were internationally measured in the Pacific before Fukushima.”

The FDA sets “Derived Intervention Levels” for common radionuclides. The DIL measurements are used “internationally” to measure radionuclide concentrations that would require “protective measures,” according to the FDA.

The FDA’s DIL measurements for Cesium 134 and 137 are 370 Bq/kg for imported foods, and 1,200 Bq/kg for domestic foods.

That puts Alaska salmon at less than .1 percent of the FDA’s danger level of the Cesium radionuclides.

Though the tests returned levels well below safety concerns, Knutson said the slight increase in Cesium levels is almost certainly traced back to Fukushima.

Cesium 137 “is present in low-levels in the Pacific pre-Fukushima,” Knutson said, but increased levels of the substance were found in the Baltic and Black Seas after Chernoybl.  “Any (Cesium) 134 right now would have to be related to Fukushima … nuclear engineers say it’s only associated with the byproduct of a nuclear power accident,” he said.

By June 2012, FDA import investigators had performed more than 32,000 field examinations for radionuclide contamination, testing 1,313 samples, including 199 seafood products.

The FDA found 1,312 samples had no Iodine 131, Cesium 134, or Cesium 137 radionuclides. One sample was found to contain detectable levels of Cesium, but was below the established DIL.