Nature Studies by Michael McCarthy: There's beauty, and mystery, in any river's flowing waters

I cannot see a river, any river, without a quickening of the spirit, and this is such an automatic reaction that I sometimes wonder if it is hardwired into the genes, from our previous existence as hunter-gatherers. If I cross a river on any journey I want to know its name, and if at all possible, stop on the bridge and gaze into its currents.

I love beautiful rivers but I love dirty and polluted rivers no less, because they are still flowing waters which hold mystery, and their potential to recover is indomitable and unending. It is almost as if rivers are one of the key elements of human existence, and I remember the thrill of recognition I felt when I first saw this truth nobly expressed by Norman Maclean, the American Professor of English and fly fisherman whose autobiography became a celebrated Hollywood movie. "Eventually," Maclean wrote, "all things merge into one, and a river runs through it."

I could not say I have a favourite river because so many give life to their landscapes, from the Hodder enriching that green pastoral part of Lancashire north of the moors, which people forget about, to the Frome watering the lushest, creamiest part of Hardy's Dorset (there are several Fromes, by the way, but the Dorset one is pronounced "Froom").

I love bullyboy rivers like the dark brooding Helmsdale in Sutherland and understated, intimate rivers like the Lydd in Devon, and small rivers with literary associations like Housman's Teme or Dylan Thomas's Aeron or Seamus Heaney's Moyola; in fact I love any river, anywhere, and so it was with great pleasure that I accepted the invitation from three French fishermen last weekend, to look at theirs. (They were friends of a friend.)

It was the Huisne in southern Normandy, a medium-sized, peaceful watercourse which is 100 miles long and eventually joins a larger river, the Sarthe, at Le Mans (which in turn flows into the Loire). Hervé, André and Emmanuel look after the headwaters, that is, the top 14 miles of the Huisne from its source near a sweetly pretty yellow stone village called La Perrière; and they look after it through their fishing club, which, France being the bureaucrat's paradise that it is, is not just a club, but an AAPPMA: an Agreed Association for Fishing and for the Protection of the Aquatic Environment.

Virtually every stretch of French river is looked after by an AAPPMA; there are 4,000 of them. Each has this double purpose, for fishing, and environmental protection, and it was the latter aspect that Hervé, André and Emmanuel wanted to show me, as well as the Huisne's own natural beauty. For the young, narrow stream is very vulnerable to the intensive livestock raising which dominates its landscape and in many places cattle have trampled the banks in coming down to the water to drink. The trampling releases large amounts of silt and sediment which ends up covering the gravelly bottoms in which trout lay their eggs. To keep the river healthy, the banks have to be fenced, and fenced-off watering-places for cattle have to be constructed.

The farmers aren't going to do this; and the state, generally, hasn't got the money; so it is left to the fishermen to organise and supervise and maintain. You can say that they're acting out of self-interest, and so they are; but Hervé, André and Emmanuel and their AAPPMA had done it, that's the point. Up and down the infant Huisne they had fenced off the banks and improved the flow, so now it ran clear through the cow-covered fields. That's what made it such a pleasure to see: it was not just a river, it was not just a lovely river, with the grayling rising to the small mayflies hatching in the sunshine of a golden October afternoon, it was a river that had been mended.

We need to think hard about zoos

They say hard cases make bad law, but sometimes it takes an extreme event to bring home to us the need to live by certain principles. One undoubted example was the mass escape of large and dangerous wild animals from a US private zoo, and their subsequent shooting.

The massacre by the forces of law and order of the lions, tigers, bears and wolves released by the suicidal owner of the Muskingum County Animal Farm at Zanesville, Ohio, has a gruesome fascination about it – when did you last hear of 17 lions and 18 Bengal tigers shot dead? What might have happened had they continued to roam free? But above all it shows that the decision to detain large wild animals in captivity is not a casual one, and one which the state needs to become involved in. That's not to say, no zoos; but it does mean thinking hard and, in every case, justification.

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