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Barbel Diet Analysis

I think looking at all the posts what is apparent is that several factors may influence average sizes increasing. As Dave says, genetics could be significant and I have often wondered if the Ouse fish genetics were largely responsible for their bigger than average size. Tench are a fish whose sudden increase in size was even more dramatic than barbels and again there could be several reasons, HNV baits clearly being among them.

Regarding the foul hooked sixteen pounder cased in Ringwood there was an interesting comment in Jim Gibbinsons excellent book Modern Specimen Hunting. Jim states we would not see the like of that fish again as "they no longer exist". Undoubtedly true when the book was written in the eighties and who of us at the time would have disagreed? But the odd event did provoke cause to wonder, one being the huge barbel that was killed by a dredger on the Cherwell in the early eighties, somewhere near Heyford I think. A very well known angler who I won't name saw a photograph of the fish and estimated it at between fifteen and eighteen pounds which would have obliterated the then record of 14.6. Probably equivalent to a 25 pounder today!
 
Graham Elliott said:
Interesting stuff. Can't completely agree with what you say Pete.

Any correlation between the rise of obesity in the human population over the last 20 -30 years
(Fast food) and the rise in barbel weights (Fast food)????

I think so!

What we are talking about is a fairly short period of max weights for many decades of around 15lb to a weight of over 20lb.


I think that might rule out climate change and mineral absorption changes as a significant factor over such a short period.

Also as a General rule, heavier feeding of certain stretches will overtime bring more fish into the area for easy pickings.
This could mean that some bigger, oft caught fish may vacate to safer areas where they have the benefit of monopolising any free food provided.

Just some more thoughts to throw into the pool (or river in this case)
Click to expand...

Graham - have a butchers at this website: Spurious Correlations You should be able to plot out your theory!

Cheers,

Joe
 
A CHANGE in diet might also be highly significant.

If, for example, barbel are persuaded NOT to eat so many freshwater shrimps by being provided with plenty of anglers' bait, then they will not be infested with as many parasitical tapeworms (the shrimp is the carrier of the larvae of the tapeworm). A reduced level of tapeworm infestation will improve the barbel's health and ability to convert ingested food.

I believe this has been a significant factor on the Hampshire Avon, where reduced weed cutting has resulted in less shrimp being eaten.

This could partly explain the large fish that Pete Reading mentioned that exist in areas that don't receive large quantities of anglers' bait.
 
Not sure the comparison with humans is valid Graham, where weight gain, all fat, is due to poor diet on high energy food and lack of exercise. The UK fish of all species ARE growing bigger, not getting fat, and doing it in completely unfished waters at times, see bream and perch in trout reservoirs.
Higher temperatures have always promoted faster growth, see carp in southern France/Spain and southern Europe.
I tend to think warmer temperatures AND a longer growing season are major factors that apply to all species, but room for more study there!
I have had scales from Ebro roach analysed, and the growth rate is double that of UK roach, even though the Spanish roach undoubtedly eat a lot of pellet, but no more than some British roach, I would think!



Tim, without a study of what barbel eat naturally, a high shrimp diet is largely speculation. They probably eat a wide range of invertebrates; I seem to remember the Avon 16 was full of alder fly larvae? Recent studies on p.laevis hookworm shows what seem like high infestations with little effect on growth, which is, like many natural processes, counter-intuitive to us!
All fish are full of natural parasites, like we are, but only very high infestations can start to have negative effects, it seems.

All very interesting, and the barbel-focussed PhD that the Barbel Society is supporting will provide a lot of insight into much of the above.
 
pete do you think a warmer climate would help barbel and other species of fish to flourish and to grow bigger and stronger,
the reason or part of it is could an increase in warmer long term climatic change aid fish to digest and utilise food better:)
 
John Walker said:
pete do you think a warmer climate would help barbel and other species of fish to flourish and to grow bigger and stronger,
the reason or part of it is could an increase in warmer long term climatic change aid fish to digest and utilise food better:)
Click to expand...


John, i sit in the British sun, for a full 2 weeks every year when it arrives, i,m still only 5`4" and as strong as popeye,s bird. ;)
 
Pete. My view was that climate change ie getting warmer theory was invalid largely because for the species you mention it was impossible to make such a significant difference over the very short periods of increased growth.

Regarding high protein food. How would feeding fish with a product that has been designed to promote growth...not do that ?

The correlation with the obese population was a simple expression of when food of rich value becomes available its eaten.
Is increased average population weight over a short period due to the sun?

I accept that warmer water will increase growth rates as in Spain/France. But would suggest nothing much has changed there over 30 years.

Breakdown of high value baits will increase the "soup" of proteins available in a river. Breakdown of bait or HP groundbait will affect the riverine system throughout.

At least people are getting a bit wiser and not starting the fishing day after piling in 5k of bait.

All fish are opportunists. Indeed on a local carp water the perch are getting bigger than ever. They are caught on meat and pellets mainly. Many trout waters get a large amount of feed into the cages used for bringing fish on and there is also the element of the fish not being seriously targeted leading to increased survival rates and the chance to grow bigger.

Water quality and possibly an increase in natural food sources may well be a factor


I would guess that the Avon project (A fantastic thing) the fish are fed high protein diet increasing growth rates.

Anyway. Its helpful to debate.

Graham
 
If our climate is changing and our Winters are getting milder/ warmer .
You only have to look at the weather and the high tempertures for the time of the year we had a couple of weeks ago .
If water tempertures are rising through the Autumn / Winter . Then would it not be logical that fish will be feeding and eating more ?
 
As has been said already, a really interesting thread. A question - do we accept that some of the barbel now being caught are actually fat (boilie belly as described above) as opposed to being just generally bigger. If so there are only three reasons
- too much food
- not enough exercise
- genetics

and the question then is what can contribute to this? Is there more food entering the rivers that in the 60's and 70's or is it just of higher quality, has breeding on some rivers led to outsize fish, water quality and environment, temperature re growing season - fish in the south generally seem to be bigger than those in the north from a historical perspective. So many questions here, all i do know is that the barbel on the Thames tributary i fish do not climb up the line for bait and the river is infested with crays. The chub are also much bigger compared to only 5 or so years ago - so something is happening and the more studies the better.
 
Paul Dowgill said:
As has been said already, a really interesting thread. A question - do we accept that some of the barbel now being caught are actually fat (boilie belly as described above) as opposed to being just generally bigger. If so there are only three reasons
- too much food
- not enough exercise
- genetics

and the question then is what can contribute to this? Is there more food entering the rivers that in the 60's and 70's or is it just of higher quality, has breeding on some rivers led to outsize fish, water quality and environment, temperature re growing season - fish in the south generally seem to be bigger than those in the north from a historical perspective. So many questions here, all i do know is that the barbel on the Thames tributary i fish do not climb up the line for bait and the river is infested with crays. The chub are also much bigger compared to only 5 or so years ago - so something is happening and the more studies the better.
Click to expand...

The increase in signal crays would seem to be very significant for a couple of reasons. First, the fish obviously eat them and get a lot of nutrients from them. Chub are the most widely known lover of crays and where the signals have taken a real hold chub weights have rocketed. The Cherwell was a prime example of this. In the eighties and nineties a five pound chub was a rarity although fish to 4.14 or so were not uncommon. Then weights shot up to a point where two or three fives in a day were possible plus the previously unthinkable capture of a six became reality. Ouse chub were also huge as were Thames and Kennet fish. Undoubtedly barbel also enjoy eating crayfish so it's yet another factor in the debate. Add to this the crayfish diet of fish eggs and a reduced population/competition for food means even more for the survivors to gorge on.
 
Paul.

Some good points. That I would add that.

1/ In my opinion we are seeing on many rivers locally to me a change in feeding habits over the past few years.
Due to the larger amount of rich food, pellets, boilies introduced we are seeing many days when the barbel seem very inactive and non competing/feeding. The Kennet is a fine example.

Interspersed with far less days when they all seem to be active and feeding. This lack of activity means they are not using up body fat.

2/ On some river sections, for example the Trent, multiple catches of good roach are being taken on small pellets fished for barbel. It's a highly nutritious food source and one guaranteed to put weight onto fish. Incidently, the recent 3.5 roach taken on the Hants Avon was caught on a boilie!

3/ Yes, crayfish are a rich source of body building material, as is Krill, salmoneggs, general fishmeal etc.

4/ Yes historically the fish in the North are smaller than down south, but interestingly enough, when you look at the BFW reports over many years, when the fish down South stop feeding, the Northern reports continue for a fair bit as they seem to tolerate the lower temps better. I would say however that sizes in the North seem to be catching up steadily. Maybe the food?


As Pete knows I respect him and his work for the BS a great deal, but his background leads me to believe that he'll accept that if we don't ask questions, we learn nothing.



Just some thoughts.
 
I have a complete open mind on this subject and look forward to reading any further research data when published. Does'nt stop us musing in the meantime though!
I was looking at Fred Crouch's piece on barbel nutrition in 'Barbel Fisher' from 3 or 4 years ago, which was quite interesting,...whether you agree or not.
Barbel and Nutrition
Like Alex, I wondered if genetics played a part with the Ouse fish, but I think it would be fanciful to equate that to all our rivers that are witnessing growth rates out of the ordinary, unless Calverton unwittingly raised a a few batches of barbel with high growth genes a few years ago!!
Unless we can study barbel on an unfished,..maybe game only catchment,..if one exists that is,..the bait theory is difficult to prove. Nevertheless, bait and feed introduced by anglers remains one of the common denominators along with both water temps. and quality I suppose,..there I go musing again!:D
 
Good discussion this, but we do need to keep an open mind. Lots of conflicting observations too!
Bream have grown huge in large reservoirs not used as trout fisheries, and not all trout reservoirs feed in cages, Graham!
Higher temps do lead to a higher metabolic rate,when food is converted to tissue more efficiently,up to a point, that is why fish grow faster in summer, like trees, and the growth rings/annuli show this and enable ages to be estimated from scales.
The current Itchen record came from a game river, unfished for coarse fish until latter party of season, and then mostly for grayling, so those big barbel are natural grown, and a good control to study further!

The current study the BS is supporting is also looking at barbel genetics, and you can now use DNA from scales to compare barbel from UK rivers.This may show a single population, or strains from different rivers, but hard to track the stocking records!
 
Fished the Itchen yesterday Pete.

No one wanted to fish for the barbel despite the record coming from yards away. Personally its a shame they exist in a game river.

I wonder what those fat trout ( I caught a dozen) are fed on?

A record bream was caught from dinton pastures. A heavily baited carp syndicate water.

It'll take a lot to convince me that weight enhancing bait is not significantly responsible for weight enhancement.

Anyway. Have a good fish with the old fella this week. All the best.
Graham
 
Get any grayling Graham?
The trout are fed before they are stocked, but live in a very rich environment anyway! They soon get cute after being hooked and returned a few times.

I reckon 80% climate change, 20% bait, but am being generous to you there!
and it will vary tremendously from river to river.
Will let you know how the Frome fishes for the old codger, will put him in your salmon swim.
 
The fish obesity issue that has been mentioned in this thread is I think a separate issue to the overall size increases we are seeing in the last few years. The increase in healthy fish sizes may or may not be due to the high protein baits, or temperature increases, or indeed a combination of both of those things.

However, the obesity (boilie belly as Hugo put it :D) is in my opinion more to do with the fat/oil content of pellets, rather than the protein levels. The shape of the larger carp is basically down to genetics, to many years of selective breeding to achieve larger fish...but I am certain that it is aided and abetted by the unnaturally high oil content of pellets, and some boilies. Certainly the saggy belies seen on some barbel nowadays must be down to that I think.

The problem in my opinion is the type of pellets that are used in the greatest quantities. For instance, probably the most popular pellets are the ubiquitous halibut pellets, which were designed to feed farmed halibut (the clue is in the name :D) and as such reflects their natural diet...which just happens to largely consist of oily fish (herrings etc.) This massively high oil content actually renders these pellets entirely unsuitable as a coarse fishes diet, especially in the quantities now used. Trout pellets (the original favourites) are perhaps not quite so popular now, but are still used in huge quantities...and they are not far behind in the oil stakes. Unfortunately, the variants of these type pellets (ellipse pellets and similar) are frequently even worse in that respect...they are often oozing oil to the extent that if they are stored in a waterproof container for any length of time, the oil pools in the bottom of the tub in huge quantities. There have been low oil 'coarse fish' pellets marketed, with healthy levels of such things, but they are not so popular...because they are not dripping oil everywhere :rolleyes:

Grahams premise that there may be a correlation between the human obesity epidemic and the increase in weight of barbel may not be as far from the mark as some have stated, in my opinion.

The massive rise in fast food in this country IS the major reason for the obesity crisis we are witnessing. It is no coincidence that cheese burgers are the most popular type of burger...the c**p used instead of real meat by the big burger chains is so bland that a layer of cheese was introduced by these damned places years ago to make this trash more palatable (fact). And then we have pizzas, fish and chips, curries and so on. The one common denominator in all of these items is MASSIVE levels of fat/oil. That, and lack of exercise, are the poor lifestyle choices that have produced the human obesity problem that is bringing the NHS to it's knees. The unnaturally high oil content in pellets/boilies...and the fact that the fish don't have to work for/travel far to get vast quantities of these harmful items (hence lack of exercise)....sounds a pretty similar scenario to me...and certainly can produce the same results.

It might also be of interest to note that prawns (my favourite food :eek:) are sadly extremely high in the bad type of cholesterol. How different are crays to their cousins the prawn in this respect I wonder? It is also a fact that eggs (one of the main ingredient of many boilies) are another provider of exceptionally high dietary cholesterol levels. Bad news all round for the poor old barbel by the sound of it.

I have no idea whether the high oil aspect of the diet we present to our favourite fish is part of the remit of the B.S. research...but if not, it should be....

Cheers, Dave.
 
Hi Dave. Yes I talked about protein levels but I was really talking about the total food value including the oil content.

And you correctly linked the fast food concept example.

Pete. Lots grayling. But roach absent. Did hook a monster big dark salmon that scared the life out if me as it leapt out of water and smashed me.

You better carry the tackle if you plan to walk that far.....

80/20. Aving a larf.

Graham.
 
Pete, the Avon chub have shown an incredible weight gain over the past two decades as I'm sure you would agree.
Given that they are happy to feed in very cold water temperatures I imagine that climate has had little effect. You could possibly argue that warmer wetter winters have not suited chub given their reluctance to feed in murky conditions but still they continue to grow.
Just a thought.
Probably guilty of oversimplifying my point but you get my gist.
 
Graham Elliott said:
Hi Dave. Yes I talked about protein levels but I was really talking about the total food value including the oil content.

And you correctly linked the fast food concept example.

Pete. Lots grayling. But roach absent. Did hook a monster big dark salmon that scared the life out if me as it leapt out of water and smashed me.

You better carry the tackle if you plan to walk that far.....

80/20. Aving a larf.

Graham.
Click to expand...

I know mate, it's just that I have a greater capacity to ramble on incessantly and thereby bore people into submission than you...sometimes works :D

Sounds like you had another good day down there Graham...leaping salmon do tend to be a bit of a wake up call don't they :p

Cheers, Dave.
 
I think the Itchen record is quite interesting, as Pete noted, a game river so not a huge amount of bait going in. New record not far off what stood as the national record for a long time, so is the 14/15lb mark the natural maximum weight for a barbel under 'normal' circumstances if there is such a thing? Yes in the past a few bigger fish, like there are a few larger humans, but genetic abnormality until recently? Or can/will the Itchen fish become 17/18lb? More questions...
 
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