GrahamM
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Bob Roberts
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As I pointed out in one of my early 'Angry' articles, I was nearly caught out back in the summer when two fish were caught and properly released after wading in the water and what appeared at the time to be appropriate nursing. Both fish swam off strongly and not given a second's further thought.
A little while later someone pointed out a 'dead' fish in the river. It wasn't dead but it was one of the fish I'd released. The river we were fishing is narrow, quite shallow and crystal clear.
I stripped off, went in and took hold of the fish that had wedged itself on its side beneath the fronds of trailing weeds. Whilst aiding its recovery I caught a flash of bronze out of the corner of my eye and there beneath another bank of weeds was the second fish. Again on its side.
Had that been the Trent I would have had no idea that these fish were trapped/ possibly dying.
Both were nursed back to health as far as I can tell. But how often does this happen to other people who sincerely believe they've done a good job of returning a fish because it swam away strongly?
Anglers talk of 20 minute nursing and so on but very few actually do it. If you've a second rod out and it goes whilst you are nursing a fish, what happens then?
What if this fish is being supported in the landing net?
In reality the majority of anglers want to fish, not hold on to a fish so the job is rushed and you an never be quite certain that it isn't belly up under a weedbed.
Me? I reckon a spell in retaining system will rule out all these risks.
A little while later someone pointed out a 'dead' fish in the river. It wasn't dead but it was one of the fish I'd released. The river we were fishing is narrow, quite shallow and crystal clear.
I stripped off, went in and took hold of the fish that had wedged itself on its side beneath the fronds of trailing weeds. Whilst aiding its recovery I caught a flash of bronze out of the corner of my eye and there beneath another bank of weeds was the second fish. Again on its side.
Had that been the Trent I would have had no idea that these fish were trapped/ possibly dying.
Both were nursed back to health as far as I can tell. But how often does this happen to other people who sincerely believe they've done a good job of returning a fish because it swam away strongly?
Anglers talk of 20 minute nursing and so on but very few actually do it. If you've a second rod out and it goes whilst you are nursing a fish, what happens then?
What if this fish is being supported in the landing net?
In reality the majority of anglers want to fish, not hold on to a fish so the job is rushed and you an never be quite certain that it isn't belly up under a weedbed.
Me? I reckon a spell in retaining system will rule out all these risks.
T
Tony Rocca
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Would you spot those two fish had gone belly up in your retention system on, say, a full kennet or tidal Trent?
Were they air bound Bob? Did you put them straight back or rest them in your landing net first whilst you had a look at them?
Were they air bound Bob? Did you put them straight back or rest them in your landing net first whilst you had a look at them?
Bob, as you say the majority of anglers want to fish. Do you think this will lead to problems with any retention system?
What I mean is a retention system, (recovery tube <- great name) would be designed for 1 or 2 fish in order to nurse them back to health, correct? What if your having one of those days were your catching a fish a chuck.
The first barbel is put in the retention system then 3-4 mins later you have a second, which I guess would then go in with the first. Again 3-4 mins later another fish is caught and placed into the retention system and so on. When would you release the first fish? How would you know which one was the first caught fish? How would you remove one fish from the system leaving the others behind? Would you have to stop fishing for say 20mins until you knew the last caught fish had had long enough to recouperate before releasing all the amassed barbel.
This I hope is seen as constructive criticism, I'm not bashing anybodies ideas. At the end of the day we all want whats best for the barbel.
What I mean is a retention system, (recovery tube <- great name) would be designed for 1 or 2 fish in order to nurse them back to health, correct? What if your having one of those days were your catching a fish a chuck.
The first barbel is put in the retention system then 3-4 mins later you have a second, which I guess would then go in with the first. Again 3-4 mins later another fish is caught and placed into the retention system and so on. When would you release the first fish? How would you know which one was the first caught fish? How would you remove one fish from the system leaving the others behind? Would you have to stop fishing for say 20mins until you knew the last caught fish had had long enough to recouperate before releasing all the amassed barbel.
This I hope is seen as constructive criticism, I'm not bashing anybodies ideas. At the end of the day we all want whats best for the barbel.
T
Tony Rocca
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I have an alternative theory as to what the problem with these two barbel may have been Bob, maybe right, maybe wrong.
Now knowing said small lazy river as I do. I know that it is at the edge of being able to support a thriving barbel population. Indeed, it was not capable of doing so untill the 90's due to very low DO levels.
How do I know this, well I was there when the first stockings of barbel took place by the NRA, 1991 I think, as I used to be the bailiff on the stretch.
The river has suffered problems periodically since.
Now given that the river is very small and shallow with far from the best DO levels to begin with, it doesnt take much to realise that the barbel will be close to the edge in any period of little rain and hot weather, like this summer.
The act of catching them was maybe just too much given the conditions and they struggled to recover in the probable low DO conditions even after having the energy left to swim off in the first place.
Maybe they would have come round in time but better still not to fish for them under the circumstances.
Now knowing said small lazy river as I do. I know that it is at the edge of being able to support a thriving barbel population. Indeed, it was not capable of doing so untill the 90's due to very low DO levels.
How do I know this, well I was there when the first stockings of barbel took place by the NRA, 1991 I think, as I used to be the bailiff on the stretch.
The river has suffered problems periodically since.
Now given that the river is very small and shallow with far from the best DO levels to begin with, it doesnt take much to realise that the barbel will be close to the edge in any period of little rain and hot weather, like this summer.
The act of catching them was maybe just too much given the conditions and they struggled to recover in the probable low DO conditions even after having the energy left to swim off in the first place.
Maybe they would have come round in time but better still not to fish for them under the circumstances.
L
Lee Fletcher 1
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Dear Tony,
"Maybe they would have come round in time but better still not to fish for them under the circumstances."
Even better than that Tony, change the dissolved oxygen content dramatically by embarking upon sound river restoration programes. Not you personally Tony, or Bob for that matter, but the club that owns/controls the fishery.
Regards,
Lee.
"Maybe they would have come round in time but better still not to fish for them under the circumstances."
Even better than that Tony, change the dissolved oxygen content dramatically by embarking upon sound river restoration programes. Not you personally Tony, or Bob for that matter, but the club that owns/controls the fishery.
Regards,
Lee.
T
Tony Rocca
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Agreed Lee.
stuart clough
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Lee....hmmm...better still, tackle the root cause of the low DO - usually organic enrichment/pollution. If the river already contains the odd decent barbel the habitat can't be that bad, can it?
Tony, I don't know which river you are referring to, but there are some rivers where there is a chronic DO problem, but more often it is rivers affected by CSO (Combined Sewage Outfall) discharges that end up with fish kills as a result of low DO levels (e.g. Thames tideway August 2003). Such events tend to coincide with heavy summer rainfall, and the DO on the same river may well be fine during dry, low water conditions (which you would otherwise expect to be the worst case). Short of carrying a DO meter on every fishing trip it is not easy to see how an angler could judge whether it was "safe" to fish under any given set of circumstances. Indeed, if DO concentrations were even approaching a critical level the first response I would expect would be that the fish would stop feeding, given that the process of digestion adds to the oxygen demand.
Tony, I don't know which river you are referring to, but there are some rivers where there is a chronic DO problem, but more often it is rivers affected by CSO (Combined Sewage Outfall) discharges that end up with fish kills as a result of low DO levels (e.g. Thames tideway August 2003). Such events tend to coincide with heavy summer rainfall, and the DO on the same river may well be fine during dry, low water conditions (which you would otherwise expect to be the worst case). Short of carrying a DO meter on every fishing trip it is not easy to see how an angler could judge whether it was "safe" to fish under any given set of circumstances. Indeed, if DO concentrations were even approaching a critical level the first response I would expect would be that the fish would stop feeding, given that the process of digestion adds to the oxygen demand.
T
Tony Rocca
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Stuart,
Investment in mid 80's in a whole new sewage works for a small Nottinghamshire town saw this river improve to what it is today, barbel only inhabit the upper reaches at the moment where the flows are greatest, further down the river becomes slower, wider, the barbel have not spread out so far. Further upgrades will no doubt come one day but at the moment during low flows a large percentage of the river will be discharge water, remember these are 80's standards works.
CSO discharges are not the rivers problem on this occasion though your point about summer downpours is right.
As lee says, river improvements would help, riffles etc, the habitat is not ideal, flood protection being the top of the list for much of the last 30 yrs.
The barbel do seem to be getting there, despite a couple of setbacks, and one section of river has benefited from flow diverters and the creation of fry refuges. This is lower down than the bit Bob is on about though.
Some of the very first barbel Calverton produced were used to stock this river, a success story, with room for improvement.
Investment in mid 80's in a whole new sewage works for a small Nottinghamshire town saw this river improve to what it is today, barbel only inhabit the upper reaches at the moment where the flows are greatest, further down the river becomes slower, wider, the barbel have not spread out so far. Further upgrades will no doubt come one day but at the moment during low flows a large percentage of the river will be discharge water, remember these are 80's standards works.
CSO discharges are not the rivers problem on this occasion though your point about summer downpours is right.
As lee says, river improvements would help, riffles etc, the habitat is not ideal, flood protection being the top of the list for much of the last 30 yrs.
The barbel do seem to be getting there, despite a couple of setbacks, and one section of river has benefited from flow diverters and the creation of fry refuges. This is lower down than the bit Bob is on about though.
Some of the very first barbel Calverton produced were used to stock this river, a success story, with room for improvement.
Bob's account of his two fish in distress in such a short time got me thinking - it must be a localised water quality problem. The posts above seem to support this.
Surely if barbel were so susceptible to going 'belly up' (never seen it myself), then we would be seeing dead barbel turning up all over the place? This would be particularly the case on some pressured areas on the Ribble, where a lot of local anglers are not very fish-care conscious (landing nets? who needs em).
Must say though, I dont like to fish the rivers (or stillwaters) myself during prolongued dry, hot periods. Same as why I dont fish for carp anymore when they are spawning. I'd prefer to catch em when they are fighting fit. roll on the next flood!..
Surely if barbel were so susceptible to going 'belly up' (never seen it myself), then we would be seeing dead barbel turning up all over the place? This would be particularly the case on some pressured areas on the Ribble, where a lot of local anglers are not very fish-care conscious (landing nets? who needs em).
Must say though, I dont like to fish the rivers (or stillwaters) myself during prolongued dry, hot periods. Same as why I dont fish for carp anymore when they are spawning. I'd prefer to catch em when they are fighting fit. roll on the next flood!..
Bob Roberts
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One thing I can say with certainty is that had these fish been held in a retention system I would a) have been aware of any problems because they would have appeared at the mouth of the 'net' and b) could have tried to do something about it.
Had it occured on a deeper river the chances are I wouldn't have known there was a problem and to attempt to swim out to fish isn't something we should really be recommending. Enough kids die during the course of a summer as it is.
I only caught one of these fish, I simply had one cast with a friend's tackle as it happens, and therefore I was able to give both fish my full attention. I wasn't racing back to recast at a shoal of feeding fish, I had all the time in the world to nurse them to recovery and I can assure you they were to all intents and purposes fully recovered when released. To discover they had suffered a relapse came as a great shock.
As to whether we should have been fishing is tricky. After witnessing the glorious June 16th brigade this summer I vowed not to fish for barbel again in the first fortnight of the season and probably not the first month. This was either very late July, or most probably August. At what point do we consider fishing on rivers to be acceptable?
Regarding low dissolved oxygen levels there are three weirs within a reasonably short distance above where the incident happened and another below. The river is also full of oxygenating plants. Could the controlling club really make much difference given that it will have limited funding available?
Stuart suggests that when DO levels become critical the fish will stop feeding. I can assure you if that were the criteria then the DO levels must have been very good because the group of fish I observed were tearing up the gravel.
The fish appear to have grown from fingerlings to double figures in around 12-14 years. Something must suit them.
But let's not get diverted into river regeneration and specific incidences if you don't mind (by all means start another topic) as there is much to discuss regarding barbel care in the wider sphere.
Had it occured on a deeper river the chances are I wouldn't have known there was a problem and to attempt to swim out to fish isn't something we should really be recommending. Enough kids die during the course of a summer as it is.
I only caught one of these fish, I simply had one cast with a friend's tackle as it happens, and therefore I was able to give both fish my full attention. I wasn't racing back to recast at a shoal of feeding fish, I had all the time in the world to nurse them to recovery and I can assure you they were to all intents and purposes fully recovered when released. To discover they had suffered a relapse came as a great shock.
As to whether we should have been fishing is tricky. After witnessing the glorious June 16th brigade this summer I vowed not to fish for barbel again in the first fortnight of the season and probably not the first month. This was either very late July, or most probably August. At what point do we consider fishing on rivers to be acceptable?
Regarding low dissolved oxygen levels there are three weirs within a reasonably short distance above where the incident happened and another below. The river is also full of oxygenating plants. Could the controlling club really make much difference given that it will have limited funding available?
Stuart suggests that when DO levels become critical the fish will stop feeding. I can assure you if that were the criteria then the DO levels must have been very good because the group of fish I observed were tearing up the gravel.
The fish appear to have grown from fingerlings to double figures in around 12-14 years. Something must suit them.
But let's not get diverted into river regeneration and specific incidences if you don't mind (by all means start another topic) as there is much to discuss regarding barbel care in the wider sphere.
T
Tony Rocca
Guest
The controling club is very well off Bob but the EA paid for the improvement works further down stream.
Still a mystery to me what caused them to go over after seemingly being fine. Must be a result of shallow water, high temps, low DO I think.
This is a barbel care issue, many responsible barbel anglers stop fishing in low flow high water temp situations, many dont, its also linked to the retention or not issue as you have highlighted.
Still a mystery to me what caused them to go over after seemingly being fine. Must be a result of shallow water, high temps, low DO I think.
This is a barbel care issue, many responsible barbel anglers stop fishing in low flow high water temp situations, many dont, its also linked to the retention or not issue as you have highlighted.
T
Tony Rocca
Guest
Oh, and I know that there are DO issues there because I used to read all the EA reports on the river when I worked for them.
GrahamM
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Simon Kelshaw
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good thinking batman,
would making the keepnet funnel like, (wider at the top, smaller at the bottom), accelerate the flow too?
Si
would making the keepnet funnel like, (wider at the top, smaller at the bottom), accelerate the flow too?
Si
L
Lee Fletcher 1
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Dear Stuart,
" Lee....hmmm...better still, tackle the root cause of the low DO - usually organic enrichment/pollution. If the river already contains the odd decent barbel the habitat can't be that bad, can it?"
Agreed. But the root causes for low DO can be associated towards many problems, not "always" usually organic enrichment/pollution. I know rivers that once contained the odd decent barbel, and some that contained odd pockets of decent fish. Long term river restoration projects turned these rivers fortunes right around. None the less, I take your valid point.
Dear Tony,
I fish a local "limestone" river where I'm hoping to become involved in a river restoration project starting soon. Elsewhere along the river similar restoration projects have been undertaken with tremendous success that provide a valuable blue print for the sections I want to get involved in.
During the summer, certain sections of the river faces similar problems to the one you refer to. As such, I don't fish it in the warmer summer months but take young Sam down there for some brilliant sport during the late Autumn and Winter.
Once the project gets under way I'll ping you a copy of the personal report I'll be undertaking as I know you are very interested in these types of projects.
Sorry guys, off topic.
Regards,
Lee.
" Lee....hmmm...better still, tackle the root cause of the low DO - usually organic enrichment/pollution. If the river already contains the odd decent barbel the habitat can't be that bad, can it?"
Agreed. But the root causes for low DO can be associated towards many problems, not "always" usually organic enrichment/pollution. I know rivers that once contained the odd decent barbel, and some that contained odd pockets of decent fish. Long term river restoration projects turned these rivers fortunes right around. None the less, I take your valid point.
Dear Tony,
I fish a local "limestone" river where I'm hoping to become involved in a river restoration project starting soon. Elsewhere along the river similar restoration projects have been undertaken with tremendous success that provide a valuable blue print for the sections I want to get involved in.
During the summer, certain sections of the river faces similar problems to the one you refer to. As such, I don't fish it in the warmer summer months but take young Sam down there for some brilliant sport during the late Autumn and Winter.
Once the project gets under way I'll ping you a copy of the personal report I'll be undertaking as I know you are very interested in these types of projects.
Sorry guys, off topic.
Regards,
Lee.
T
Tony Rocca
Guest
Im sure it would be interesting Lee, thanks.
stuart clough
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Lee, I wasn't trying to suggest there is no point in river restoration (or habitat enhancement/improvement, as is more often the case), just that you can "restore" as much of the river as you like, but if you have chronic DO problems or CSO discharges the works will not achieve their potential.
"But the root causes for low DO can be associated towards many problems, not "always" usually organic enrichment/pollution."
Do you have some examples of other root causes for low DO?
From Bob's description of the feeding activity it is very unlikely that DO levels were borderline at the time of capture. It would be possible for DO levels to have fallen rapidly post capture (eg CSO discharge upstream), making the recovery more difficult. Can you remember if there were any thunderstorms around at the time Bob - not neccesarily overhead, but somewhere in the catchment?
If not then it is a mystery!
"But the root causes for low DO can be associated towards many problems, not "always" usually organic enrichment/pollution."
Do you have some examples of other root causes for low DO?
From Bob's description of the feeding activity it is very unlikely that DO levels were borderline at the time of capture. It would be possible for DO levels to have fallen rapidly post capture (eg CSO discharge upstream), making the recovery more difficult. Can you remember if there were any thunderstorms around at the time Bob - not neccesarily overhead, but somewhere in the catchment?
If not then it is a mystery!
T
Tony Rocca
Guest
Stuart, Is it not possible that with very warm low water the barbel were ok going about their normal day to day stuff but found it a bit too much pulling against Bobs 2.5lb test rod (joke Bob). Small barbel, tiny river so short fight and enough energy left to swim away but not enough DO for full recovery after. Just thinking out loud really as I would like to know what went wrong.
If not low DO then what else?
Algal bloom peaks and dies, BOD up, DO down, not always down to CSO's.
If not low DO then what else?
Algal bloom peaks and dies, BOD up, DO down, not always down to CSO's.
stuart clough
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Hi Tony - you have made several references to "low" water and "shallow" water in your posts, but in principle this is good for DO levels as it increases the surface area to volume ratio. Temperature is obvioulsy a key issue, as would be low velocities.
Certainly the fight would increase the oxygen requirement of the fish significantly, but as I said, if it was borderline I'd be surprised if they were "ripping up the gravel". So if we accept the DO wasn't borderline, then the normal "hold them in the flow" recovery technique should have worked.
Of course what happens during the fight is that the white muscle is brought into play, and this operates anaerobically (without oxygen). The by-product of this form of respiration being lactic acid, which accumulates in the muscle - similar to cramp in humans. In this condition the fish wouldn't want to swim off powerfully, but they could limp to the nearest weedbed??
As regards algal blooms, you are right that algal die off could increase BOD. However, I didn't suggest it was always CSO's that caused low DO, but that organic enrichment was commonly the root cause. As you will know, algal blooms are most commonly caused by organic enrichment in the first place.
So where does that leave us? On the basis that fully recovered fish in normal DO conditions don't go belly up in the nearest weedbed, I would suggest that either the fish hadn't fully recovered, despite appearances, or the DO crashed sometime after capture.
Certainly the fight would increase the oxygen requirement of the fish significantly, but as I said, if it was borderline I'd be surprised if they were "ripping up the gravel". So if we accept the DO wasn't borderline, then the normal "hold them in the flow" recovery technique should have worked.
Of course what happens during the fight is that the white muscle is brought into play, and this operates anaerobically (without oxygen). The by-product of this form of respiration being lactic acid, which accumulates in the muscle - similar to cramp in humans. In this condition the fish wouldn't want to swim off powerfully, but they could limp to the nearest weedbed??
As regards algal blooms, you are right that algal die off could increase BOD. However, I didn't suggest it was always CSO's that caused low DO, but that organic enrichment was commonly the root cause. As you will know, algal blooms are most commonly caused by organic enrichment in the first place.
So where does that leave us? On the basis that fully recovered fish in normal DO conditions don't go belly up in the nearest weedbed, I would suggest that either the fish hadn't fully recovered, despite appearances, or the DO crashed sometime after capture.