Posted by: AAPGAI | April 6, 2010

Grayling under the microscope

Grayling under the microscope – Ron Holloway

Ron Holloway - AAPGAI My great friend John Goddard mentions in his recent article in the January issue of the FF&FT magazine that on the water he fishes on the Itchen he has found that the grayling are becoming increasingly more difficult to catch, particularly the larger grayling.

It is suggested that the cause of this perceived phenomenon may not be solely due to the lack of fly, but to the constant unrelenting use of catch and release of the grayling, in conjunction with the greatly increased fishing pressure there is now on many of our rivers. It would not be surprising to find on some rivers that during the season there is hardly a single day when the trout and grayling do not see an array of artificial flies and nymphs thrown at them. There is little doubt in my experience that wild trout and wild grayling do learn quickly to become more wary and far less exuberant in their taking habits of surface artificial flies and submerged nymphs when subjected to consistent high fishing pressure .

As with stocked trout, wild trout and grayling history and personal experience shows that constant fishing pressure and unrelenting catch and release of any of these species increasingly makes the fish more difficult to catch. There is no doubt in my mind that a population of fish subjected to such pressures do learn, it is a matter of self protection and survival !

Coln Grayling

History teaches that before the use of Catch and Release became a popular management tool and grayling fishing became more popular, grayling were treated as vermin on many classic chalk streams. In my early days of river keeping on the chalk streams all grayling if and when caught were instantly killed and none returned irrespective of size. It is little wonder that those wild grayling populations of yester year remained very naive and comparatively simple to catch. These fish were only allowed to make one but very fatal mistake in their lives. So they had no chance to learn from the catch and release experience so they were not taught to be cautious in the future! Many grayling populations of today are regularly fished over with dry fly and nymph, day in and day out for season after season. Many small young of the year grayling and even some of the larger one to two year old fish are caught and released more than once, so it is little wonder they have eventually learnt from the experience and that these medium to large grayling that survive catch and release are now increasingly becoming very difficult to catch.

Similarly with stocked trout in some “put and take” still waters where constant Catch and Release is the rule, these rules soon teach the trout to be wary of anything that moves or even looks like food. It has been shown quite conclusively that heavy fishing pressure and regular Catch and Release in such situations can eventually stop fish feeding altogether. To such an extent that in some circumstances the trout eventually dies of stress and or starvation when in fact there is plenty of good natural insect life in the water.(See Alex Berendt, Two Lakes Conference 1980)

John Goddard states in his article that the amount of surface insect activity has reduced over recent years on the Itchen, as it has done on other well known rivers, and I tend to agree with him on that score. Fortunately the numbers and overall biomass weight of wild fish in the form of grayling in the Itchen for example still appears to be very healthy, so if there is not sufficient surface fly activity to attract the grayling to feed on the surface there must be sufficient sub surface natural food available considering grayling are predominantly bottom and mid water feeders.

In my opinion if fishery owners wish to improve the sporting quality of the grayling fishing on their rivers, a managed or regulated return to a to a total catch and kill policy would soon remedy the perceived problem of uncatchable grayling. Grayling normally breed very prolifically in most chalk streams, so the wild stock biomass of grayling would not diminish and would remain in a healthy state. There is a firmly held belief that unrelenting Catch and Release of Grayling on heavily fished chalk streams, all be it being “ the modern thing to be seen to do” these days, is unnecessary and over time does far more harm than good to the sporting quality of a fishery. Other than that, grayling are great to eat.