Don't know whether the otters help or hurt the fishing but just consider watching them as part of my enjoyment in being outdoors.
One day while fishing a treeline I caught a short crappie and there happened to be a blue herron sitting on one of the trees near by and I tossed the short to the herron and it was able to swoop down and get the crappie in the water. As I worked further down the treeline the bird would follow me perched in the trees. I caught another short but I tossed it too close to the boat and the herron didn't get this fish. The herron stayed with me for around 45 minutes of fishing and finally flew away after I was unable to catch anymore fish. Don't know how long this cranky sounding bird would have stayed with me if I had been able to catch and toss another to it.
“There is no difference between communism and socialism, except in the means of achieving the same ultimate end: communism proposes to enslave men by force, socialism—by vote. It is merely the difference between murder and suicide.” Ayn Rand