TROI’s FX-1 tag is a small round plug with a magnetic base that can be pressed into a fitted hole or secured by the magnet to the metal in a larger recess. (TROI tags are available from William Frick ...

Now DFO is proposing that all narwhal tusks bear a permanent metal tag to ensure they were caught legally. That idea, however, is being met with resistance as it would mean drilling holes through ...