Where is the evidence to suggest our rivers are broadly incapable of supporting the current otter population Howard? That's quite a statement.
Yes there appears to be an obvious conflict between barbel in smaller rivers and otters, but that doesn't mean to say that the rivers are incapable of supporting the current otter population. The fact the otter population is what it is currently rather turns that argument on it's head.
We keep hearing from some anglers about the (alleged) impact of otters on other wildlife, notably wildfowl especially coots, moorhens, swans and bitterns. On this forum I've even read claims the otters are responsible for decimating the UK water vole population.
I'm all for angling forging new and powerful alliances with non-angling groups, personally I feel that is the only way that real progress in improving our rivers will ever be made, but in order to for this to happen, and for anglers to be viewed as desirable allies, we really must make much more effort to base our arguments on sound, credible evidence.
If anglers knock-on the door of the likes of the RSPB or the Wildlife Trusts, (I use these two organisations as I know them both well and understand their firm commitment to conservation science and evidence-led policy) and start making claims about the impacts of otters on riparian wildlife, then firstly they need to be credible, and secondly they need to be able to backed up by some empirical data. Pictures of otters attacking wildfowl are unlikely to generate any response other than bemusement, it will simply be viewed as a picture of a generalist predator doing what generalist predators do best and numerous spraint surveys have shown otters predate birds and other wildlife so I'm struggling to see what benefit a few pictures will provide? On the other hand present them with some hard data which suggests otter predation is causing a marked decline on a particular species or community of species at a population level then those anglers will be taken seriously.
The problem with all the anecdotal claims about the impact of otter predation on other wildlife, and I'm not denying that otter predation can have an impact on a short-term local level, is that they rather fly in the face of the plethora of the extensive bird population survey data which is out there. BTO survey data suggests the UK swan population is an high is it has ever been. Moorhen's, whose population tends to fluctuate widely, don't appear to be declining, Coot's are doing rather well, as is the Heron and the UK Bittern population is literally booming. Numerous studies have found habitat degradation and mink to be the key factors behind the decline in the UK water vole population, some research implies water vole predation by mink is greatly reduced when Otters are present.
Unless there is empirical evidence to suggest otters are impacting on other wildlife at a population level then I'd suggest this is an argument that angling should avoid getting into. Best to concentrate on building alliances based on the shared goals of habitat improvement and water quality - that's the way forward imo.
