Human0815[You cant test Fish with a Geiger-Counter or he must be so polluted
that he is glowing already , you need a Spectrograph
Apparently a 5kg food sample can do it.
Here is some children’s education
Gamma radiation is the most penetrating. Even small levels can penetrate air, paper or thin metal. Higher levels can only be stopped by many centimetres of lead, or many metres of concrete.
It seems odd, that radiation would be shielded by the fish, enough to effect Geiger counter measurements. So I assume if the counter detector was right next to the fish there won't be an issue. The issue will happen if your hold the Geiger counter a long distance away.
edit on 090705 by Liberal1984 because: (no reason given)