Barbel Diet Analysis

[David Gauntlett]

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.

Perhaps they are getting chubbier Dave

Cheers, Dave.

 

[Dave Taylor]

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



Cheers, Dave.

I'll let you know when the eyes start glazing over Dave

 

[Pete Reading]

Chub on both the Avon and Stour have been getting bigger for quite a long time, they always had highest growth rates for UK chub I think, and without crayfish, and again often on very lightly fished stretches.Warmer temperatures and a longer growing season would once again be likely to be much bigger factors than angler bait in causing size increases over the last 30 years.
Dave, not clear how your logic works; if they feed all year round, it will not counter the enhanced effect of increased temperature and longer growing season??

The biggest Stour chub were often found on almost completely unfished waters.
The last seven pounder I had on the Avon was from an almost completely unfished stretch, not so long ago it would have been a British record!
I remember fishing the Avon for four years in the eighties before I caught my first four pound plus chub, now we do not weigh them unless they look like sixes!


I am sure bait has some effect on these growth rates, but not as much as we think.
It could be investigated in the short term in tank experiments, I suppose.
Just needs the funding and the will to do it!

 

[Graham Elliott]

Pete
Yes well you know that in the eighties a four pound chub was a good un. Of course, since the 90's they have had fantastic food to eat. And three decades of higher temps wouldn't haven't done too much to add weight on.
.
Even the Kennet and Loddon are throwing up 7's.

Fish also have a tendency to swim from one place to another.

I know....like a dog with a bone...

 

[Dave Taylor]

Pete,...my assumption was that because chub continue to feed in colder water temperatures they would therefore continue to grow as normal regardless of climate, ie, not being reliant on a prolonged warm season to obtain extraordinary growth.
What I failed to factor in to my 'theory ' is that a fish will not always convert that food into growth during low temps.
I find the average percentage growth of Avon chub since the eighties even more fascinating than the barbel,..but best I stop now before I disappear up my you-know-what!

 

[Fred Wilton]

Pete,
Fish do grow big in tanks if fed a nutritious diet ask Brian Hankin about the Goldfish he saw in a tank in my kitchen in Kent many years ago when he and a mate whose name was something like Bontoff (my apologies for the spelling) came down to fish Johson's Lakes......Fred.

 

[Graham Elliott]

Hello Fred.

I think we met when you popped down to see Dave and Richard on the Wye.

I made you and the mrs a cuppa in the cottage.

Welcome to BFW.

 

[Mike Hodgkiss]

Interesting thread this . Re the influence of global warming on fish growth '' over the last 30 years '' . Thirty years ago takes us back to 1984 [ hmm] ] were water / air temperatures significantly lower then ? I don't know, but have my doubts . It is an accepted fact that air temps are significantly warmer in the South of England than in the North and in the past this was usually seen as the explanation for all the big barbel coming from the Southern rivers . However if you look at the current big barbel [ Trent and Dove fish ] these are northern ish rivers and presumably temperatures are lower ? This could be seen as evidence that barbel f grow big wherever they are because of the oil / fat rich baits that are chucked in the rivers in large amounts . With regard to the statement that many very large barbel have come from lightly fished stretches where little bait comes their way . Don't these fish swim around ? Barbel are well known travellers , perhaps they are sweimming off to stretches were significant amounts of bait are available ? Having said that , all that swimming would keep them in trim and work off their bolie bellies

 

[Alex Gowney]

I still think genetics play a big part in fish size. The Ouse fish in the mid nineties weren't fed on pellets and boilies yet were well above the national average. And what about the original carp in Redmire? They were massive well before the days of HNV and not just averagely massive either. Anyone who has read Chris Yates book will be familiar with the giant fish that Rod Hutchinson described as looking like a man swimming in the water! Estimated at probably over eighty pounds! Has anyone ever satisfactorily explained the huge size of fish in Redmire? Even the gudgeon were extra large by all accounts! I tend to agree with Mikes point that in thirty years has the climate changed that much? I don't think so. I can well remember working in shorts and T shirt on building sites in November on more than one occasion back in the eighties and how about 2005 or 2010 for really cold winters? Not much evidence of global warming then. So many factors to consider and all have probably contributed in some way to the phenomenon.

 

[Ash Gould]

I doubt there is huge variation in Barbel genetics across different rivers for that to be a factor in some barbel attaining larger weights. Obviously genetics play a part in fish diversity, as it does for all species, but I doubt it would explain why Trent fish get bigger than another rivers fish etc

The barbel at Adams farm on the Ouse more than likely came from, or were breed on from, a stocking from the river Severn, which in turn was stocked with Barbel from the Kennet.

Environmental factors were probably much more significant, namely lack of competition as indicated by lack of biomass in the river. A Barbel's greedy dominant nature would also mean they would more than likely capitalise on any competitive feeding situations too.

It would be interesting to see an analysis of Barbel's skeletal growth across the ages, as this would indicate if they are getting significantly bigger as opposed to heavier.

Would a fat 17lber have the same size skeleton as a lean 14lber? I reckon so. Therefore diet and increased environmental conditions for growth (global warming) would be the most significant factor in different weights across different rivers.

 

[Alex Gowney]

I can't really see how global warming would affect the Ouse but not the Thames for instance though Ash The Ouse in the nineties had a good population of chub and roach too so it's not as though the barbel had all the natural food to themselves. And what is your view on the Redmire carp?

 

[Fred Wilton]

Hello Graham,
Thanks for the welcome,and the cuppa.

 

[Pete Reading]

This is becoming more interesting as the complexity of it all becomes apparent, but a few points should perhaps be clarified before we go any further.

Global warming should not be confused with climate change, and these terms are often confused.Global warming is a fact, and means that the average temperature of the planet has risen over the last century, and faster than any previous evidence shows.
The main effect of global warming is variation in LOCAL temperatures, sometimes an actual drop at times, and more importantly, changes in local climate. This can be floods, drought, rapid temperature changes, intensity and frequency of storms and rainfall patterns etc.
Not sure of the figures for the UK, but climate change for us has led to warmer summers and winters,on average, earlier springs and later autumns, note the last October being the warmest on record. So, a longer growing season for everything, as well as higher metabolic rate with higher average temperatures anyway.

We need to study the actual data about different rivers, but we are now looking at 19lb plus barbel from at least seven rivers, off the top of my head,and including Ouse and Thames, and 14 pounders are seemingly everywhere, after three 14 pound fish headed the record list for decades. There will be variation between rivers and stretches, depending on lots of factors, but it seems to me that all our rivers have benefited to some extent from something that has boosted barbel growth nationally, and indeed that of other species too.

I think that we first started to notice fish getting bigger in the seventies, and was it not tench that came to attention first, with a record of 9lb 1oz in 1963 being exceeded time and again as double-figure tench started to appear. My statement about the last 30 years is a bit too short a timescale, in retrospect, as fish being caught then had been growing for the previous ten or twenty years, benefiting from all the factors that have probably combined to enhance their growth rate.

It needs a scientific approach to gather together all the data to come to a proper conclusion, rather than rely on our individual recollections and pet theories, but good to think about and discuss nevertheless!

Redmire carp were, as far as I am aware, a small population of a fast-growing and long-lived strain of fish, originally imported by Donald Leney from Europe, in a small and very enriched water, so a very special case, but growth rates were explainable. They probably did benefit from climate change too!

 

[Anthony Pearson]

Would a fat 17lber have the same size skeleton as a lean 14lber?

It could Ash, however does better nutrition increase skeletal growth and therefore the maximum potential weight? A number of factors influence bone development, growth, and repair. These include nutrition, for example, vitamin D is necessary for proper absorption of calcium in the small intestine. In the absence of this vitamin, calcium is poorly absorbed, and the inorganic salt portion of bone matrix lacks calcium, softening and thereby deforming bones. Vitamin D is relatively uncommon in natural foods, except for eggs. But it is readily available in milk. With both being used in the manufacture of boilies for example could this lead to bone growth that in the past has been restricted by a natural diet. Human beings have got taller over the years and better nutrition has been partly responsible, so why not the same for fish? Surely a longer fish has the frame on which more weight can be supported?

 

[Graham Elliott]

A very sensible post Anthony.

Pete. Did tench weights increase positively after the "old" close season was abolished when it became normal to see spawn laden fish in the fishing mags, as continues now days.

This includes of course perch bream carp. Etc.
Guessing timeframes but this was around the time when hnv baits wete becoming more popular. Followed by increased fishmeal use.

Incidently. Never seen a barbel longer than 36".

Graham

 

[Alex Gowney]

So Pete, it would appear from your view on the Redmire carp that the genetic make up of that particular batch had a big influence on the size they reached? I think they came from Poland originally and the term "Leney carp" was often used in the eighties. Redmire was/is indeed a rich water, hence the huge gudgeon, and it will always be a kind of mysterious mecca for most anglers, even though the days of the monsters has passed.

Has anyone else ever wondered why fish vary so much more in size than other creatures? After all, a shoot would expect most of it's pheasants or partridges to be pretty well peas in a pod size wise, the same for mammals generally, so why do fish have so much more variation in skeletal size?

 

[Neil Smart]

So Pete, it would appear from your view on the Redmire carp that the genetic make up of that particular batch had a big influence on the size they reached? I think they came from Poland originally and the term "Leney carp" was often used in the eighties. Redmire was/is indeed a rich water, hence the huge gudgeon, and it will always be a kind of mysterious mecca for most anglers, even though the days of the monsters has passed.

Has anyone else ever wondered why fish vary so much more in size than other creatures? After all, a shoot would expect most of it's pheasants or partridges to be pretty well peas in a pod size wise, the same for mammals generally, so why do fish have so much more variation in skeletal size?

Good question, and from what I understand from fish biology which is not much, I will assume from what I do know is that the size of fish can and is determined in say Goldfish (King Carp) according to the available area the fish has to live. As many will know fish having been kept in aquarium to adults when transferred to a pond will quickly grow in size relative to their new surroundings.

So the primary factor here is available volume that controls growth rate in fish.

Other factors are food availability and temperatures according to species, such as Carp who flourish in warmer climes.

However this is just a few examples of how fish can control their weight / size according to conditions, more so than many other species, mammals and birds would not have the same control of growth if they were penned and then released into a field, so fish growth is more 'elastic'. But of course once the skeleton is formed it cannot reduce, I assume.

Inland rivers or ponds where greater variables apply, fish have to adapt.

 

[John Walker]

Neil, most shoot release the pheasants and partridges once they are fully grown
which in turn will be most from same age and out of same breeding stocks,
obviously they will be similary sized

 

[Dave Taylor]

Good question, and from what I understand from fish biology which is not much, I will assume from what I do know is that the size of fish can and is determined in say Goldfish (King Carp) according to the available area the fish has to live. As many will know fish having been kept in aquarium to adults when transferred to a pond will quickly grow in size relative to their new surroundings.

So the primary factor here is available volume that controls growth rate in fish.

Other factors are food availability and temperatures according to species, such as Carp who flourish in warmer climes.

However this is just a few examples of how fish can control their weight / size according to conditions, more so than many other species, mammals and birds would not have the same control of growth if they were penned and then released into a field, so fish growth is more 'elastic'. But of course once the skeleton is formed it cannot reduce, I assume.

Inland rivers or ponds where greater variables apply, fish have to adapt.

Neil, why is it that when some fish of the same age who live out their lives in the exact same enviroment with the same food supply outgrow one another?
Why is it that if you breed from the large fast growing fish, or their small slow growing compatriates you will often replicate the very same factors in their respective young.?
Here is a pic. I took this morning of two Ghosties in my pond, both purchaced at 5'' fish 23 years ago. The one on the right weighs 18lbs the one on the left only 3 to 4lbs.

The larger of the two is a female and the other a male, but that would not explain the differential in size,...it has to be genes.
I have bred goldfish in a 13000 gallon pond and none of them have grown to over 4'' long, because they have come from a breeding stock of small fish.
No matter how much space or food is made available to them their optimum size will remain small....it has to be in the genes.
To futher illustrate the gene pool theory, the original fish were red and white.
There are always some young from a hatch that do not develop the parents colouration and remain brown in part.
Due to heron and kingfisher predation the stock remains at a healthy level, but it is the red and white fish that have been eaten mostly, leaving the brown, less conspicuous fish to carry the flag. The young from these fish are predominately brown.
This has of course been nothing other than natural selection, but also shows how certain genes can become predominate.
This could have happened to barbel or chub with regard to growth genes.

 

[Ash Gould]

I can't really see how global warming would affect the Ouse but not the Thames for instance though Ash The Ouse in the nineties had a good population of chub and roach too so it's not as though the barbel had all the natural food to themselves. And what is your view on the Redmire carp?

That is not really what I wrote though Alex. The effect of global warming on increasing conditions for growth would affect all rivers, but there would be other variables to factor in across different rivers/geographical areas.

I also mentioned that barbel would dominate any feeding situation whereby inter species competition came into play. I have many a fishery report from the 90's through to the modern day, the biomass for the river stayed pretty constant over that period with numbers of fish seemingly decreasing; it suggested that the river can support a certain level of consumption; bigger fish meant fewer fish and IMO this became almost perpetual (until the big fish died).

Redmire?? If the carp were in there for long enough and there is enough food for them then why wouldnt they grow and grow? Thats what carp do, it is a myth that they grow to the size of their pond. Survival is dependent upon being bigger than any other fish that could eat you

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Are we actually seeing increased skeletal growth in barbel or just them getting heavier. Without that data we are speculating.

As Graham suggests it is rare to see Barbel longer than 36inches. This suggests that Barbel have not actually got 'bigger' (longer) but rather are heavier. They are putting more weight onto their same as always sized frames.

To use the human analagy refered to earlier, about humans getting taller through better nutrition etc If the same were happening in barbel they would be getting longer (which is indicative of skeletal growth) not just heavier. I think they are just getting fatter and heavier.
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Really we know very little about the fish we catch. The visual size and weight yeah but what about its age and gender or even how healthy its is?

Are all 5 year old male barbel the same size?:confused: Should an adult use emoticons?

I dont know about either, but would wager that being shaoling creatures they have evolved to be roughly the same size as each other (when the same age). Weight differences in barbel of the same length would perhaps then be down to diet and health???

Its all conjecture on my part but beats working.

ATB
Ash

The above post was written whilst I wrote mine and I would add that a lot more selective breeding techniques are used in the fish breeding trade and as such predominating genes would be squewed. No such selective breeding would take place when barbel reproduce, more a natural selection process.