Of course,some good came of it-----surgical instruments have long been made from steel raised from the wrecks of German ships scuttled at Scapa Flow ( the metal is not irradiated,apparently )----perhaps there's a song lurking there ??
       As to fishermen being treated differently.....Not by the Germans, they weren't !!! Captured fishermen and the crews of merchant ships were treated VERY badly in Germany,being paraded in front of the populations of large cities, their heads shaved,and being manhandled and spat on !! A seaman was a seaman,to the Hun !! ( Logical, of course, but rather unsporting,really).