The Angling Star, Monday, November 27, 2000 (page 32)

I LIKE playing with statistics, as it is possible to reach any conclusion that you wish, by simply ignoring the bits that you don't like, and carefully selecting the bits that suit your argument.

Let me give you an example.

Chris, who runs Ravensthorpe Trout Fishery assures me that, on several occasions, he has seen cormorants swallow 3lb trout.

The RSPB, on the other hand, claims that a cormorant eats a little over 1lb per day.

I suspect that the average is somewhere in between the two, and depends very much on the amount of fish available. Many are the tales of anglers disturbing feeding cormorants that have been so laden with snap that they have to disgorge up to 1lb of fish before they could even take off,

For the purpose of this article, I am going to err on the side of the RSPB and assume that the average daily fish consumption of a cormorant is 1lb 8oz.

As I am in the fishery business, I buy and sell lots of fish and, again, I can juggle statistics to suit any argument that I wish. If the 1lb 8oz of fish were, let's say, small barbel (not the EA vintage), they would cost me over £30. If I were selling small roach and skimmers to a dealer, however, I would expect to receive £4 for them, he in turn selling them on for around £6 to £8 to clubs and associations.

Being extremely conservative, I am going to settle for an average of £5 per pound, and therefore a cormorant has an appetite that costs £7.50 per day to satisfy.

Are you with me so far? An average of the many reports and surveys indicate an inland cormorant population of around 15,000 during the winter months, reducing to a couple of thousand birds during the Summer.

I really have no idea as to whether or not this population is stable. However I suspect that the breeding just about keeps pace with the untimely deaths suffered by thousands of them each year. Woolvey really isn't the place for surveys as no clock has yet been invented to measure the life expectancy of any bird entering the 'no fly zone'.

Let's therefore say that 15,000 birds feed inland for 180 days per year and eat 1lb 8oz of fish per day, at a total value of £7.50 per bird.

Statistics may lie: mathematics however, is an exact science. So here goes. 15,000 x 180 x £7.50 =£20 million per year = 20 million fish - 4 million pound weight (1,800 tonnes).

Is there anyone out there, especially the RSPB, that wishes to challenge either my statistics or my mathematics so far? Good.

Let me now play around with a few more statistics. Combining the wisdom of both he Environment Agency and that of Dr. Bruno Broughton, the country's top fisheries management consultant and biologist, an average natural water contains (15,000 x 180 x 1.5lb)/300lb 13,500 acres around 300lb of fish per acre.

13,500 acres per year of total fish depletion, probably equates to some 30,000 of partial fish depletion to the point of seriously the ability of the water to provide reasonable sport.

In Yorkshire speak, the fishery goes barren, all 30,000 acres of it each year.

I am now going to become much more specific and relate the above pretty unchallengable statistics to your own fishing in the simplest form possible, making only one small concession to assumption.

If an average natural fishery sustains 300lbs of fish per acre, I am gong to assume that it ceases to be a viable fishery when the stocks drop to 160lbs per acre, Yorkshire speak again.

Let's take the two rivers that are closest to the heart of many Angling Star readers, the Trent and the Witham. Both have roughly an average width of around 50yards, depth is unimportant.

One cormorant eats 1lb 8oz fish for 180 days which equals 270lb of fish during his 6 month stay inland. This represents total fish depletion for 86 yards of river, or using the 50% depletion figure that renders fishing a waste of time, for over 170 yards of river.

It therefore only takes 10 cormorants to destroy the fishing over 1 mile of river each year.

The 600 resident cormorants of Attenborough gravel pits alone therefore, destroy almost 60 miles of fishing each year on the Trent be eating their way through over 70m tonnes of fish. I don't know what the cormorant population is like on the Witham but if you work on only 19 cormorant destroying only 50 per cent of the fish on close to one mile of river each year, you will have a pretty good idea why the local clubs and associations are struggling.

I began the article by saying how much I liked statistics, so I will feed you with a few more. Much of the River Avon upstream of Warwick is less than 10 yards wide, in fact close to my place the cormorants have been working a once prolific stretch some 5 to 10 yards wide. One solitary cormorant therefore reduces the fishing to a point of being useless, for a full half mile in just one winter. No one fishes there anymore.

I know that the above figures seem totally incredible yet, I have run them past some very respected people in the fishing world, and whilst they drew gasps of amazement, no one has actually disagreed with them.

Possibly, in fact probably, the current failure of fry to survive the winter, due to the chemically cleaned water is a significant factor in the appalling state of some of our rivers but, I am sure that most of our precious stocks have been converted to guano, and are now piled up under the trees in the many inland cormorant colonies.

Dr. Barry Rickards, Jim McDonald and Ron Clay, can I please ask for your opinion and your views on the validity of the above figures.

Could it be that the many bangs going off at Woolvey have affected my mind, as I still dream of waking up in the morning, and popping down to the Trent for spot of stick float fishing the way it used to be?