Most other coarse fish species can adapt to either still or moving water so why shouldn’t the barbel? Qualified fishery scientist Neville Fickling marshals the evidence both for and against…

FROM TIME to time I dip into the correspondence on some of the website forums. I only get time to respond to those directly concerning me and certainly do not have the opportunity to read all the various strands. Recently stillwater barbel seemed to be generating a lot more heat that light and I certainly had no wish to get involved. With, I think, over one hundred postings on the subject, there’s a risk of getting entangled for a couple of weeks. I have skimmed them in the name of research because the editor asked if I’d do a piece on stillwater barbel from a fishery scientist’s point of view.

Obviously, there are arguments for and against the stocking of barbel into a Stillwater environment, but the biggest voter against must surely be the Barbel Society. The key argument against is that: “It is not natural for barbel to live in stillwater.” The implication is that it is probably unfair or even cruel to deprive barbel of the water running over their bodies.

Now please excuse me, I’m going to have a bit of fun here. Have you ever seen a barbel pine for a river? Have you ever heard one whining because it cannot find a piece of water with some pace? I’ve not noticed any letter to the Times:

“Dear Sir
I wish to comment about the disgraceful situation at Floggits Fishery where barbel have been stocked into stillwater.
                                  Signed.
                                   A.Barbel”

I suppose this is not surprising because like the rest of the fish we fish for, barbel cannot write, speak or play scrabble. Does a barbel know that it is in a river as opposed to a lake? Is a barbel at a biological disadvantage in a stillwater compared to a river? These are the questions we need to ask, but first let’s look at some facts.

About fifteen years ago a friend of mine was on a fish rescue operation working underneath the cooling towers at Castle Donnington power station in Derbyshire. Among the fish rescued were some barbell around the 3lb mark. Our esteemed friend decided to stock some of this barbell into our water nearby – Alder Pool. For a couple of years we caught these barbel while carp fishing and on the initial run you couldn’t tell they were not carp. Then one summer after we had fertilized the lake the Canadian pondweed grew like mad. What then happened was quite unusual. Many readers will know that the pH of water is a measure on a logarithmic scale of the acidity or alkalinity of a solution (in water). The lower the pH number under 7 the more acid. The higher the number above 7, the greater the alkalinity. Most waters we fish are pH 7 or 8, but there are daily changes in pH. These are caused by carbonic acid in the water. Carbonic acid is derived from carbon dioxide, a product of respiration produced by all plants and animals. During the day the plants use carbon dioxide as part of the process of photosynthesis (i.e. takes water and carbon dioxide and builds more complex molecules such as sugars). At night because photosynthesis depends on light, the carbon dioxide intake ceases. Instead CO2 is given out. Changing the amount of CO2 dissolved in water (as carbonic acid) can alter pH of water, particularly if the water is poor in calcium salts (buffering capacity) which moderate pH shifts.

On our lake we saw severe pH shifts during each 24 hours and all the fish became badly stressed. Worse still the fish louse, Argulus, flourished and soon all our fish were covered in them. The carp lost weight, did not feed and swam around restlessly. All the other fish, including chub, barbel, roach and pike were even more severely affected. Many of them died. In the end we had no more barbel, though chub re-colonized the lake via a pipe from the River Derwent.

No happy ending here for the barbel. However, what was interesting happened the year before. I always liked to catch bait for the lake for my zander fishing. During one of these bait-catching sessions I caught some three-inch barbel and saw others as well as small carp in my swim. Now I have always been convinced that those barbell were born in the lake. You could argue that they swam up the pipe like the chub, but it is interesting that we have never seen a barbel prior to stocking them or after the barbel died. If barbel were colonizing the water regularly it would happen continuously. I assume the lice bumped off the barbel and small carp.

The lake is a gravel pit and at the time there was a wave-washed gravel shoreline, which I’m sure, could have been used for spawning. I appreciate that the case I present here is not totally watertight (oops!), but logic dictates that it is probably valid.

The fact that the lake is not colonized naturally by barbel is in itself interesting. While chub and bleak seem to have an affinity for migrating into stillwaters, barbel clearly does not, which to my mind gives weight to the anti-stillwater barbel argument. They obviously do not look for an environment alien to their natural one. This in itself is interesting because most species of coarse fish show a considerable degree of flexibility. Carp, for example, are what you would consider to be a stillwater species. In fact, if you look at a barbel it is really a carp modified for living in a river. Yet does the lack of specific hydrodynamic shaping hinder the carp in any way? Just go to the St. Lawrence in Canada and the United States and see how carp are everywhere. They even spend all day in 40ft to 60ft of fast flowing water!

Clearly body shape is not as important as you’d think. I’m still trying to work out how bream thrive in the Trent. After all, bream must be a classic stillwater fish, yet they can keep up in waters as pacey as the Trent. What is clear is that many of our coarse fish species are adaptable. Some such as rudd are less adaptable than their cousin the roach – put rudd into a river system and they rapidly drift downstream, presumably seeking slower water.

Gudgeon on the other hand are a fish we normally associate with rivers. Yet they thrive in stillwaters. Over the years I’ve netted many fisheries, finding large populations in amongst the roach and bream. Gudgeon are not that far removed from Stillwater barbel, having a near identical body shape, yet we are being led to think that it is unfair to stock barbel into stillwaters. We must assume that gudgeon in stillwaters have been stocked at some point, being a much more widespread species than barbel. Only recently have barbel been stocked into Stillwater and so far it looks as if they are thriving. We know that gudgeon breed prolifically in stillwaters and now we have barbel in stillwaters we may find out that they can adapt to this environment.

The biggest most limiting factor as regards a river species is oxygen supply. Barbel, like any other river fish, and also those that often live in stillwaters, are acclimated to higher oxygen supplies. Therefore take a river-born fish of any species and it will struggle in a stillwater where oxygen levels are low. Barbel will be no exception. However, the reverse is also true – a river fish can become acclimated to lower oxygen levels in a stillwater fishery. I remember well some barbel turning up on the River Delph, a fen drain that lacks flow in the summer, but does run like a train in the winter. The fact that they died in a major deoxygenation is neither here nor there, because a load of pike died as well!

On the Yorkshire Ouse in the great drought of 1976 it became a Stillwater, yet the barbel continued to get caught. They did have a high incidence of Argulus, which does indicate they were stressed, but who wouldn’t be when the water temperatures were up in the 20s C?

Things have changed a lot since I caught my first barbel. We now have fish farms such a Calverton producing barbel by the thousand. They are reared in Stillwater for at least part of their life and have to be ‘trained’ in raceways to be able to cope with flow. Stocking fish such as these into stillwaters does not seem to be a problem to me – especially as they are Stillwater fish from the start!

What is immoral is taking barbel from rivers to stock into stillwaters. I should qualify this statement by saying taking from rivers, which are fished to stock stillwaters. The subtle difference is that I’m sure river barbel can adapt, but it is not a good idea to remove them from rivers where anglers will be deprived of the sport they have come to expect. A lot of fish have gone walkies that way.

I would worry if someone opens a Stillwater offering specimen barbel fishing, you might be entitled to ask, “Where do they come from?” Hopefully this will not become part of our specialist-fishing scene. My personal opinion is that Stillwater barbel as okay, but what is the point? Surely small carp would offer more or less the same enjoyment. It must be the novelty value and that in itself is not a good enough reason. With a few commercial fisheries suffering from overstocking problems a lot of attention is being directed at them by representative organizations such as the Institute of Fisheries Management. Those people who run commercial coarse fisheries have to take care that they are not going to struggle to justify stocking barbel into stillwaters. I see no problem, but then I am not the voice of angling, nor do I have the ear of the Environment Agency. On the other hand, the attitude of the Barbel Society (unless I’ve badly mis-read it) seems totally over the top. A bit of moderation from all those involved might not go amiss.

This article was first published in Coarse Angling Today September 2001