Saturday morning, 5am. The Wensum flood plain is looking spectacularly gorgeous.

There is light in the sky and the blue above is growing more vivid little by little. There are two churches on the horizon, both giving perspective and serenity to the scene. It's like something out of ages past, centuries long ago. I am trotting the enfeebled summer flow for roach, on a whim and a prayer perhaps. I'm almost sure I saw a decent fish in the swim just a week ago and hope has got to spring eternal. In fact, the whole scene that I'm fishing in is so reminiscent of 1976.

I feel I am a lad again, bursting with the same optimism, experiencing the same sort of heat that the region wilted under all that time back. Bizarrely, I'm actually fishing the very, self-same swim that I did one Saturday morning during that heatwave 42 years back. It's like time has almost stood still. Of course, my rod and reel are more advanced but the float hasn't changed much, nor have I, deep down.

The point of this piece is this, my fishing diary from 1976. When I returned from last Saturday's expedition, I checked the entry just to make sure. Yes, I had fished the same swim, in the same month, in the same heat, with the same method and with the same bait. Back then, that glorious morning, I had roach of 2lb 7oz, 2lb 6oz, 2lb 4oz and 2lb 2oz. This time around, I had a dace of two ounces and a single roach the same size. The diary also reminded me that in '76, I counted 100-plus lapwings on the meadows around me, 30-odd skylarks, over 30 herons, more than 50 hares and troops of corn buntings. The Saturday I've just 'enjoyed', it was a blank for the lapwings, the corn-buntings and a single skylark, a solitary heron and a brace of hares. In short, the vibrant valley of '76 has become a silent tomb in now in 2018. I won't be alive in a further 42 years and perhaps it's as well. If the trend I and so many others have witnessed continues, we will live in a sterile world then.

But back to the fishing this century. Water temperatures, I've been told, have been recorded up to 25 degrees C on some of the waters hereabouts. No wonder stillwater trout fishing is completely in the doldrums and it is worth noting that the excellent Barbel Society has closed its waters down lest the fish suffer from being caught in such extreme conditions. In my experience recently, tench have been extraordinarily erratic, feeding some days but appearing completely comatose on others. I've been able to make no sense of their behaviour whatsoever. So let's thank goodness for chub that will still chase a bait in air temperatures of 30 degrees, when the sun is beating down and the river levels are as low as a baby's bath water. My diary of '76 tells me I was catching occasional chub back then, but they were much fewer and far further between than they are now. And smaller. On the Saturday evening after my roach failure, I actually went back and took a fine, fat, heatwave chub of perhaps five and a half pounds. That would have been a show stopper 42 summers ago.

So what should we anglers be doing with temperatures not showing much sign of change? Should we be fishing at all or be following the Barbel Society's initiative? If we do fish, perhaps we should consider fishing dawn or dusk or even in the night when temperatures are more acceptable. What we must do is minimise the stress on any fish that we catch in every single way. Keep nets, surely, must be put to bed until the weather changes and, vitally, don't leave anything in a sack for seconds, no matter how important the photograph or the weight might be to you. I had a chub die on me five years ago in a summer heatwave by doing exactly that and I've never got over the shame. Summer keep sacks are now another thing of my past.

I have a conundrum. I love the Bridge Inn stretch of the Wensum at Lenwade. The bailiffs are welcoming and generous with advice and the banks are beautifully kept. Several times a week I park there, walk the river and just watch for fish in the sparkling waters. This last 10 days, I have noted two barbel of decent size in the fishery, but here's the rub. Every time I visit, the barbel are in exactly the same position, pressed hard in crevices under tree roots on the far bank. You wouldn't think they are alive looking at them until you view them close through binoculars and you realise they are. They are glorious, beautiful but almost impossible to spot and, whatever I've dreamed up, equally impossible to catch. Going back to 1976 again, I'd never caught a Wensum barbel and I've got the strongest possible feeling I'm not going to do so again this particular summer.