Otter

[Robert Richbell]

How does anyone know their territory's have shrunk and you're not just seeing the same otter repeatedly with the occasional chancer encroaching from time to time? It's not like you can tell them apart as they all wear their own unique style of hat!

of course in many cases i am undoubtedly seeing the same otter. However an extreme aberration to the large territories occurred 3 years ago on the Kennet. I was fishing bright sunlight, lovely warm July day and 2 otters appeared swimming upriver. Took zero notice of me. I rung a mate maybe 2 miles away upriver to tell him what was headed his way and he replied your lucky i have 5 of the buggers, 2 adults 3 young. Mine i believe were juvenile. I then rung another friend fishing another couple of miles away in the opposite direction to tell him our woes and he had 3 otters
visible to him at that point. Now that was a 1 of situation, maybe, but i doubt any river can support 10 otters, 4 adult 6 young? in 4 miles of river for long even with the vast numbers of Crayfish that exist. they may have strayed into each others territory, i know where i was fishing has had otters for a number of years, with no problems but to stray 10 miles or more is pretty unlikely. At the end of the day there is still too much we dont know about the impact so , given how much money we give the EA for fishing, i think they should be doing some serious research to find out what, if any and how much damage otters are doing. Apart from fish, obviously and crayfish they also take a lot of juvenile waterfowl. My opinion, coz thats all it can be, from my observations is that otters have changed their habits and there are too many. Interstingly i only saw 2 otters last season , but then i rarely bothered fishing the Kennet , i now do a 200 mile round trip to fish for Barbel.

 

[Robert Richbell]

I certainly haven't fished the Kennet as long as you Robert but even over the past 5 years, my experience matches that you have described. It has been the last two years where I have noted a quite dramatic increase in sightings- almost always at night.

I have wondered, however, if this isn't more otters, just resident otter or otters needing to hunt more frequently and take more risks. The quite dramatic fall in barbel stocks would surely trigger a shift the otter's behaviour. It might be a simplistic view, but to my mind the natural evolution of this model, without intervention (systematic fish restocking), would be otters needing to expand their territories or moving large distances to find new hunting grounds and in doing so, the risk of an early death must surely increase (conflict with other otters or indeed something much larger, with metal doors and an engine).

Otter numbers would then naturally decline, unless of course they simply increased a switch to alternative food sources- birds etc. You might even imagine them going toe to toe with foxes in colonising our urban landscape.

In the meantime of course.....

Saying all that, in my view the otters on the Kennet are simply amplifying more profound issues such as over extraction to help meet the water demands of a growing population. What might help there is perhaps some sort of container, like a massive bucket, to help collect rain water.

I know i come across as kill all otters but that is not what i want, i still get a thrill from seeing them, followed by despondency if there is a "pack"
I also believe that if we did not have the problems you have outlined above , along with a massive reduction in crays and a total reduction in cormorants, otters would be far less of a problem. Given that you now have to carry out due diligence, impact assessments and risk assessment before you pick up a pencil or screwdriver at work, what were the muppets at Natural England and the Otter trust doing. A nice idea but woefully inept application to instantly fix a non existent problem. imo. Oh forgot to mention Rainbow trout that regularly escape from trout farm sand are yet another non native species competing in our rivers.

 

[Anthony Pearson]

I've just found the answer to the question I was going to ask, but here it is anyway:

Do otters eat signal crayfish?

My thinking was that the explosion in the population of signal crayfish may coincide with an increase in otter numbers. Apparently this doesn't appear to be the case, not at least according to this research:

Abby Stancliffe-Vaughn is researching signal crayfish at Anglia Ruskin University
and she gave us some background information on this.
“Otters prey on crayfish throughout the year with crayfish activity (and
therefore dietary prevalence) at a peak during the summer months. Otters
make excellent surveyors - you know there is a thriving population of white
clawed crayfish when spraints are full of crayfish bits and there are claws all
over the place! Thankfully otters also consume signal crayfish in large
numbers. However, rivers with signal crayfish can be quite impoverished (as
they eat near enough everything and destroy the breeding areas for fish) so
don’t always have good populations of predators like otters.

Back to the drawing board then.

 

[David Gauntlett]

I've just found the answer to the question I was going to ask, but here it is anyway:

Do otters eat signal crayfish?

My thinking was that the explosion in the population of signal crayfish may coincide with an increase in otter numbers. Apparently this doesn't appear to be the case, not at least according to this research:

Abby Stancliffe-Vaughn is researching signal crayfish at Anglia Ruskin University
and she gave us some background information on this.
“Otters prey on crayfish throughout the year with crayfish activity (and
therefore dietary prevalence) at a peak during the summer months. Otters
make excellent surveyors - you know there is a thriving population of white
clawed crayfish when spraints are full of crayfish bits and there are claws all
over the place! Thankfully otters also consume signal crayfish in large
numbers. However, rivers with signal crayfish can be quite impoverished (as
they eat near enough everything and destroy the breeding areas for fish) so
don’t always have good populations of predators like otters.

Back to the drawing board then.

That report is both confusing and worrying at the same time Anthony. Worrying in that they have confirmed what we already new about Signal crays destroying the breeding sites, but confusing in that if the river is impoverished, as in no fish, why don't the wretched otters hang around and scoff all the damned crayfish, and THEN move on

Cheers, Dave.

 

[Robert Richbell]

maybe crayfish are an opportunist food source, if they get a whiff of a predator they are prety quick getting into burrows. Otters do munch em, i think i read somewhere recently that on a stretch of the HA , which never had crays, or very few, most of otters diest are now crayfish. Course thats probably because they have eaten most of the Barbel, Chub and Pike

 

[John Walker]

thats it, drain the kennet for a few months that,ll kill the devils