Decline in Barbel Populations

[Graham Elliott 1]

Colin.

Its the summary of a research project.

Re body mass. A Professor of Exeter University advises me that high protien food intake can lead to unusual sexual behaviour in cyprinads.

As I have said. I believe that hormones in riverine environments may well be the overriding problem ( and have for many years) I just believe that the high oil pellet feed should be investigated.



Graham.

 

[geoffmaynard]

Perhaps, and just a thought, which I'm rather sceptical of, the genetic integrity of the stocked barbel could be a factor. This is the salmon scientist's latest buzz-word excuse for failing populations. As I've said, I'm sceptical but if they are right, it might be a factor which also affects coarse fish. Apparantly there are studies which show roach can be genetically different in different parts of the same river - so with all fish coming from just one pool, Calverton, problems with genetic integrity could affect breeding populations.

Personally I think pellets are over-blamed. Everything eats them, they melt down and are gone in hours, unlike boilies... Even the clots who pour in 1/2 cwt can't do too much damage when there's a decent flow...

(awaits incoming!)

 

[Graham Elliott 1]

Geoff.
Incoming....

Only joking. I wouldn't dismiss your genetics theory out of hand. In fact it probably links in with the change from kennet to trent fish.

I don't think pellets are over blamed, because the only research done was on stillwater fish. And that highlighted problems hence the restrictions commercial pools made on food types. Eg. Low oil.

Regards your river comments. Please refer to data given earlier to Colin regards pellet intake.

Not all rivers are raging torrents or as large as the Wye and it seems the smaller rivers are most affected.

Graham

 

[The bad one]

I see the point your making Colin “exercise in maths.” But in fairness all good scientific research stands or falls on its maths, or more correctly its statistical analysis and the statistical tests used - T Tests, Paired T Tests, ANOVA, Twinspan, Chi Squared and many more.
Yes I know, there’s lies, dammed lies and political statistics. Worlds apart the two types of stats! Stats used for scientific research are not generally the same types of stats used to analyse political stuff, which tend to be crud, not advancing much more than the mean, mode and median. Scientific stats go much further than this and are used to iron out things like any bias in the way the data was collected, visual clustering, etc. Most using a mathematical confidence level of a 95% chance of it being correct, or a 5% of it being incorrect.

What stats tests (if any) were used on the analysis of the collected data of this research we don’t know as we only have the Abstract of the report to go on and that doesn’t say! Nor does the extra two pages you can get by clicking on the “Have a look inside” button (top right of the page).
So without the full report it’s hard to say what stats tests, if any, were used and whether they were the right one.
So for now, all we can say is, “the devil is in the detail!” And that would be in the materials, methods and results.

 

[Ray Wood 1]

Graham,
As much as I admire your resolve in trying to get the answers you seek, I fear you are flogging the proverbial "dead horse". Although I hear that there just might be something going on within the BS.

Isn't it a fact that the BS in league with the EA having been papering over the cracks for years by the continual restocking of juvenile barbel in many of our rivers? Rivers that have and still are suffering from poor natural recruitment. All good stuff, but there seems to have been little done by either to find out why this poor natural recruitment was and is still happening.

All well and good one might say doing surveys on where spawning areas are along our rivers, or a PHD project on the river Teme.

All these things are scheduled to take years to reach any conclusion on the collapse of barbel stocks on some of our rivers. If the current trend in decline continues by the time these surveys reach any conclusions it will be to late.

The truth is Graham the cracks are so big now I fear it is already to late, we may just have to accept that the halcyon you and I have enjoyed where barbel are concerned are over. A defeatist view? No an acceptance of reality I'm afraid.

There might just be some mileage In Geoff Maynard's sceptical thought that the stocked barbel's generic integrity may be a factor.

Have you had any response from Calverton Graham regarding the questions you formulated with TBO?

Someone said river fishing might no be here in ten years time, perhaps these are the problems they were talking about that would bring that about?

Regards and good luck in your search for answers.
Ray

 

[Rich Frampton]

Pretty much agree with that...... the relationship between the BS and the EA is, I am afraid, not as strong as I thought it was, it can't be.Judging by the inactivity of the R&C with regard to the Lambourn sewage issue it would appear that it is easier to hide behind the AT. If the relationship was strong and any influence was there then surely, whether the view held was identical to the AT, the society would be demanding some sort of explanation and action?? But no..... unless there is something to be gained (whether ego massage or print space) then nothing is done. Sorry that is blunt but that is how it comes across from looking from the outside looking in.
My hat goes off to Howard....he is bucking the trend and is just getting on with it. I dare say he will be told to rain it in otherwise the structured and co-ordinated approach of the R&C leader will be compromised. In the meantime Howard...good on you!

 

[Titus]

Oh dear Rich, I don't want to say I told you so but hey, there is life after the bs, a couple of years of being a knocker should get it out of your system and then you can start to get on with your life again.

Welcome to the dark side mate.

 

[wozzy]

I live along the river calder in Mirfield, West Yorkshire and was predominantly a roach river and one of the best in the 70's. Since its revival through polutions back in the 90's I have seen some big changes. Roach are hardy and made a big come back only for barbel to be amongst some catches, with many but small being caught throughout the stretch. Nothing above 2lb! Bradford No1 did used to introduce them, whether the EA carried on doing this I don't know. (The EA have wanted to class this river as a trout river for many years so I guess Barbel would not be on their agenda) Then those fish appeared to dissapear. But recently some big 10lb+ barbel have been caught and many to 6lb, throughtout the stretch.

The point I am trying to make is fish move and certain hotspots then aren't now, but I do know although none have been caught on the stretch I live for sometime I bet a night session would produce some.

 

[wes79]

I'm just throwing this out there ok guys but if this stuff can kill an adult man then what is it doing to a juvenile fish?
I've not researched this properly myself yet but it certainly made me consider its effect on the fish, that are eating this stuff after all not just touching it.

Maggots | Total Fishing

Maggots Q&A

How are maggots coloured?

Maggots are naturally white and are generally coloured by eating meat that has already been died. The dyes used to colour the meat include rhodamine (for fluoro maggots), auramine (for yellow maggots) and Sudan Red (for red maggots). Although the first two are carcinogenic, because the dye is within the maggot the danger to the angler is thought to be limited. It should be noted that following its research into red maggot dye, the Dutch Angling Federation banned the used of all coloured maggots in Holland and is calling for a European wide ban.

Is chrysoidine still used?

The bronze maggot dye chrysoidine is also carcinogenic but the big problem with the use of this dye is that it’s used to coat the skin of the maggot and thus rubs off on the skin of the angler in use. The death of Clive Smith in the 1980s was closely linked to his regular use of chrysoidine and many anglers out there think it has been banned. However, all that happened was that suppliers of the dye like ICI discouraged its use in angling, and it is still available. Although leading suppliers of maggots and pinkies now use a bronze dye alternative called Methic Orange, there are many tackle dealers and some suppliers out there who still use chrysoidine to dye their own bronze maggots and if you are in any doubt, you should ask. So-called ‘disco pinkies’ used commonly in the east of England are pinkies raised on rhodamine dyed meat and then skin-dyed with chrysoidine.

 

[law]

Yet on the flip side, there is a sharp increase of barbel in some rivers. The Mole and Wandle being 2 local to me.

 

[black kettle]

The plain fact is, not all rivers are experiencing a decline in barbel or other species of fish for that matter. Many are experiencing exactly the opposite and all are exposed to pellets of various types. As I have said before the river Trent probably sees more pellets than any other river and its wild fish stocks are going from strength to strength.

If we were to be talking about smallish still water environments I could understand the theory, but with rivers that in many cases are miles and miles long? It makes no sense especially when one considers that anglers bait makes up only a tiny portion of a wild river fishes diet anyway.

We have witnessed the rise in otter predation especially among record sized barbel at a variety of venues. Only recently another record sized barbel fell prey to an otter on the river Ivel. Of course the death of record sized fish are sharply noticed but what about the lower year classes of fish? These are also falling prey to otters just the same. So when one calculates that an otter makes a kill and only eats enough to satisfy itself and leaves the rest, its easy to see just how quickly an otter or group of otters can wipe out certain year classes of fish fairly rapidly along stretches of certain rivers. And because otters leave their kills as carrion because they never return to an old kill, fish left by the otter/s are often quickly acquired by other predators like foxes, rats, mink, crows etc so it can take a while for the bigger picture of fish stock losses via predation to emerge.

Then add lots of other long term reasons and causes to the mix like agricultural practices, over abstraction and habitat loss. These events take years to have an effect on wild fish stocks and their recruitment so are not visible to the untrained eye. Even so, they ARE there and they DO have a massive impact on wild fish.

We already know that too much of almost anything has a bad effect on health. The high oil content of anglers bait has already been scientifically conducted but these effects are related almost entirely on fish in captivity and a tiny amount of fish deaths from still water environments with subsequent post mortems having been conducted. Conclusive proof for all still water environments and their fish stocks? Hardly. And is there a shred of evidence to warrant a survey or scientific research into the effects of pellets in rivers? No. What evidence there is however are the bodies of fish left to rot by otters. The thousands of fish left floating dead and dying after pollution ravages a river or known spawning grounds slowly silting up due to agricultural practices further upstream.

These are just some of the REAL threats posed to our rivers and their fish stocks and is where we should be looking for answers for declines in fish stocks.

Regards,

BK.

 

[wes79]

Yet on the flip side, there is a sharp increase of barbel in some rivers. The Mole and Wandle being 2 local to me.

I have to agree with this, my local rivers are getting better each year, facts are facts and the river reports coupled with personal experiences would show this to be true.

Definately less Roach though (which is a big shame imho).

 

[cg74]

Yet on the flip side, there is a sharp increase of barbel in some rivers. The Mole and Wandle being 2 local to me.

But how many are there as a result of natural recruitment?