Magnetic fishes

I've been reading "the Meaning of the 21st Century" by James Martin this summer, amongst a lot of other insight I got reading this book is that in order to ensure a sustainable fish population at least 20% of the oceans needs to marine protection areas. On the small Island that I spend my summers (my fathers birth place) used to be filled with all kinds of fish, and as a youth we ate fish almost everyday, now the sea is almost devoid of fish (well you can still get herring and mackerel). I hope that the countries of the world can get together and solve this and the other large problems our worlds are heading at. To solve part of the problem I've designed some magnetic fishes specially designed to destroy the fleet of "Supertrawlers" (floating fish industries): Karpatron Sargassotron Roby Dick