Here is an idea to save marine mammals (dolphins, seals, and porpoise) from drift nets. Is it possible to place a sonar device on a net which transmits an Orca or whale vocalization which alerts other marine mammals of their location, scaring the mammals off while not disturbing the ability of fishermen to catch fish? I had this idea any years ago, but do not know the process of presenting it. I hope at least that if someone with the know how reads this, that they will give me feedback on its success or failure.