well,, I was once a specimen angler, and a successful,Carp, catfish, chub, bream, tench, ect ect, many approaching british record size. I had been doing it from early childhood, both father, grandfather, were successful anglers too, occasionally you would see an otter, they were never in such numbers to affect the fish stocks as they have done in the last 15 years or so, I live [and for 3-4 years was the keeper]on a relatively small private estate [around 1000 acres, with a bit more shooting rights adjoined] there are also one lake of approx 5 acres and two smaller ponds, the fishing I controlled as bailiff of an exclusive syndicate as part of my job, then one day I caught but was unable to detain [short of shooting at the van] a group of people releasing otters, It decimated the fish stocks within a week, defra were contacted,they were unhelpful, as were the broads authority, and anyone else, there was a government approved scheme to release otters it wasn't thought out well and there suddenly 100s of them everywhere, many of them with no fear of humans at all, they would swim up and try to steal fish as they were being played. then then took to the various small dykes connecting the lakes,ponds, and surrounding waterways, they just seemed to kill everything and eat very little of the kills, they then arrived at my garden pond over a mile away, [a 7600 gallon pond I had dug by hand some 20 years previously and stocked with carp, tench, orfe, grass carp, and sterlet, and other various fish, some were over a metre in length and would come and take food from your hand. they damaged almost every fish they didn't kill, digging the hole to bury them broke me, my entire plot is fenced, it made little difference they climb well as well as being proficient at digging , my neighbour lost his fish the following week, neither of us have restocked, the way the lakes are situated makes it impossible to erect otter proof fences, then they started on the ducklings even testing the resident swans the penn held the nest and the cobb taking on each otter in turn, without going in to detail I and another intervened, I believe without that intervention the swans would have lost, at the time the fellow who also witnessed it stated,, those swans were fighting for their lives, those otters were having a game with them, a game with deadly consequences for the swans. then they started on game birds, yes I've seen hen pheasants jump on and drowned by otters, the last straw was when they reached the small partridge pens at various locations around the estate. you have to realise all this was done with total protection by the law. we have no fish in the lake,pond, and my once beautiful pond is now a haven for frogs,newts, and even the odd mallard. the carp were of the "redmire" origin something every carp angler will be aware of , it would cost over a 100k to restock and I suspect the same would happen again. that's not my call I only live/work here. I'm semi retired now, I still shoot over the estate and anywhere else where needed as I have an open ticket. I don't fish any more, its really not worth it around here anymore.
I hope that gives you some idea of my comments regarding otters and I'm really not after any conflict on the forum, If anyone feels against my views strongly as I adhere to them pm me, I'll send you a postcode we can discuss it in more detail in my yard.