Where have all the fish gone?

The end of the month of May has seen me reflecting.

My parents live next to a river-more specifically part of it, an old millstream-in Dorset called the Frome.

When they first moved there at the end of the 1980's, sunny May evenings would see the air over the river teeming with gnats and midges, and there would be the constant sound of small splashes as brown trout and young salmon leapt from the water to feed on these bugs.

Those airborne insects are still there, but the sound of fish jumping has been greatly reduced, if not gone. Why is this?

Is there sewage in the river? Maybe, I suppose. Are there excess nitrates from farm run offs? Well, the river weed seems to be growing particularly well, so maybe. A rise in air or water temperature? Possibly.

But whatever it is, it's the realisation that in thirty years of my own life time I have seen change and damage to one aspect of the natural environment almost undoubtedly caused by humans in one way or other.

How can we accept this?