Radio active fish do not glow in the dark. To test for radio activity in fish you have to use a blue or yellow LED light (available at Radio Shack). To check the fish it is best to place it on a white platter or all white surface. The neutral white color is necessary to the test. Any other color surface and the test is not reliable. To test you turn out the lights in the house and then move the blue or yellow LED across the fish. If any radio activity is present it will appear as light green specks in the fish. Obviously this test is performed on the meat of the fish, not on the scales of the fish. Most fish that is contaminated will have minimal radiation presents so any green specks may be hard to see but if present will be visible over the entire area of the fish meat and never concentrated in one area of the fish. I’ve only tested one fish that showed very visible green specks which I ultimately made me wonder how it passed government inspections using a much more sophisticated version of this simple home test technology.
I’m guessing the green coming off is from traces of cesium or something? I’d think you’d want to use a real scintillator that responds to actual radiation and not a color reflection. I’ve never heard of this method, do you have a link to how it works? Thanks.