That is extremely unusual. If they catch the critter my first thought would be to check it for rabies. I’ve never heard of a rabid otter before but then I never heard of a rabid caribou until one was killed and diagnosed on Alaska’s North Slope many years ago when I worked there.
We used to liveaboard in the San Juans, WA. and fished, recreationally, for Salmon. A number of times you’d fight a salmon for a while and then the line would pay out radically, then release. Invariably you’d real in a Salmon w/ the belly missing. Then the otter would do the backstroke while he dined.
Yep. Otters do get rabies. I remember a few years ago there was an FR thread about a man attacked by a rabid otter.
I believe that any mammal can get rabies.
Its fairly common, if there are otter pups around. You can find YouTube videos. They'll even attack crocodiles
I had a close encounter with female otter with pups 15 years ago but she didn't attack. We did have a 10 second eye to eye stare down.