I spend much of my time sussing out rivers around the country for my so-called work and found myself yesterday on a high wall looking down into a crystal clear run of water.

The flow skirted the old stones of a one-time salmon croy (a platform built into a river to give anglers better access) and in amongst the ruins lived a shoal of 40, perhaps 50 barbel. In the bright sunshine, every sparkling scale on the fish stood picked out in burnished gold. Their fins glowed pink, orange and blood red. The lithe bodies of the barbel were balletic in their liquidity, some were 10lb and more, but even the large ones exhibited breathtaking grace. I don’t really have a favourite fish species, but barbel must come close.

I was there to do more than watch. I had with me best friends Ian and David, and of course, dog Bailey, whose christening nearly 10 years ago I regarded as some kind of compliment. It’s true to say all four of us were absorbed just watching those fish and even felt a slight reservation about catching them, wondering what right had we to trample into their ordered world. To make our unease worse, two hours of baiting had built up their confidence until their trust in the boilies we were feeding them was complete. Needless to say, first cast and David had his fish, one of the smallest in the shoal. We rested the swim an hour, fed the fish back up and debated whether we should try for another. We needn’t have worried ourselves. The fish decided for us.

Over the following two hours, our perfectly-positioned bait lay there disregarded by every barbel in the swim. That’s not quite true - many fish came close, even very close, but every one shied away without making a mistake. We had the perfect grandstand view and in the bright light could see every move of the fish, read every page of the narrative. We didn’t fish especially well on reflection. We assumed that given the number of fish and given the fact they were guzzling the freebie boilies that a second hook offering would picked up soon. Not so. Every one of those barbel had worked us out, seen through our grubby little plot.

Had we REALLY wanted that second fish, what should we have done then? We could have gone elsewhere, come back in two hours and made a careful cast that might well have proved successful because the first cast is always your best bet for any fish in any situation. We could have reduced the size of the hook from an eight to a 10 because an overly-heavy hook is always an impediment to success, though you want one strong enough to land the fish.

Almost certainly, in this case, our undoing was the line cutting through the water from our high fishing position down to the bait beneath us. Repeatedly, barbel homed in on the bait and felt the line an instant grazing their flanks or catching at their fins. We say them react, squinting away, showing a flash of flank. They weren’t scared exactly, but they were put on alert and the other shoal members almost certainly picked up on the scent of danger. Possibly a lead core leader would have lain less obtrusively on the river bed and got us over this hurdle - though with its weight, it might have become more frequently snagged amidst the fallen remnants of the croy.

In the event, our limited success was not a problem to us. We had a fish, which was enough and, as I have said, our reluctance to even fish at all was a strong one. We were happy to reel in and leave these stunning creatures to enjoy their day. The session, though, does make you think, or it should.

Had we not watched those fish and known there were a score or more a nose length from our baits, we would never have guessed there to be a fish in the swim. We would have sat there in reassuring ignorance, confident that we were doing nothing untoward, apart from fishing the wrong place of course. This is exactly what happens in endless fishing situations up and down the land, whether you fish bait, fly or lure, in running water or still, freshwater or salt. For every wild fish caught, a score or more escape completely without an angler often even guessing at their presence. I could have given 10,000 examples of this that I have witnessed over 60-plus years, but this one will do.

As a postscript, David was using a veteran John Wilson Avon, perhaps the most successful rod ever marketed. It felt clumsy to a degree and its technology has been long outdated but, my, what a history those rods carved out for themselves. This old warrior of a tool certainly dealt efficiently with David’s fish in a very squeaky bum situation. When John designed his Avon, the Wensum was bristling with barbel and now, by comparison, there are barely any. How sad this made me feel.