Just a few thoughts on the distribution of large Barbel.
Ignoring genetics, and assuming that Barbel do live 25 years, then one of the 1st parameters must be the river should have a good history such that Barbel have been there long enough to have colonised the river and there are enough fish reaching old age on a regular basis. I would also expect Spey River Barbel to be smaller then their slow to medium river cousins. Then we have availability of food, the quality, quantity and length of time which it is available i.e. long summers short winters etc and or how much bait is going in. Then it?s competition from other fish, this may be due to a few bad years spawning, combinations of poor winters and summers etc etc. I?d be looking at gaps in the age class of fish in the river.
So unless global warming kicks in sooner than it is doing, it?s going to be some time before our northern rivers can compete with those in the south. But that?s not to say that the ratio of big Barbel won?t in the near future be a bit more evenly distributed than it is now.
From a statistical analysis point, how many of the top fish are repeat catches of the same fish. If you are counting fish distribution then you can?t count the same fish twice.
