Not all canned tuna fish is the same. Most national brands of tuna use fishing methods called trawl, pure seine or long-line fishing, which is designed to get the maximum catch in the fastest time. The problem? Instead of just harvesting tuna, these methods also attract a significant amount of "by-catch," which includes aquatic species like turtles, dolphins, stingrays and sharks. If you love tuna and want to do the right thing, look for brands that use pole fishing. This is the method done for centuries with a fishing pole, bait and fishing line to catch one fish at a time. Brands like Wild Planet practice this method and have nearly no by-catch.