My dad and I used to do something like that on his lobster boat when I was young, and it was a hell of a lot of fun. He would always have a bag of M80's and quarter sticks on the boat and if we got a dogfish in the traps he would cut their arse open, stick an M80 in, light the water proof wick and throw him overboard. The fish would start to swim away and BAMM, dogfish parts flying everywhere, very cool
Another thing I used to do when you just get absolutely over run with dogs is leave the dog on the hook, cut him open and release him back down to the bottom. In a few seconds the dogfish would be eaten alive by his former companions and you could reel in slowly and beat the hell out of the 10-15 or so cannibal dogs with a gaff, swords work good too, tried that once

. After doing that a few times you could get rid of a bunch of em quickly and make an area fishable again.
If you can't get away from em, at least have some fun at their expense
