I agree with Howard that of course rivers in this country are less polluted overall....looking at the big picture as they say. However, you can pick out certain waters that are not so lucky...not by a long way, and others that are better but still not good. In the North, rivers have improved dramatically, as heavy industry has declined...some waters have virtually been brought back from the dead. The same can be said of the South to some extent, but as it never was so intensively industrialised as the North and Midlands, the difference is less noticeable in general.
There are many small rivers that continue to be hammered by pollution down here, going up and down between rebirth and almost total wipe out like a fiddlers elbow. My little river Colne is one that is getting slowly worse, or so it seems to me. Mind you, in this case it is because the river is connected to, (and in parts actually running through) the G.U.Canal, and the numbers of residential boats permanently moored on that have risen to phenomenal numbers over the last twenty years. We now get a horrendous grey sludge colouring the water during the first few heavy floods, which can persist for some weeks until it has flushed through to some extent...I wonder what that might be
Even ignoring individual cases like those, there is obviously still a long way to go on many rivers. Some are not as good as successive governments try to tell us, otherwise the EU would not be threatening the UK with punitive measures for continuously failing to bring them up to the required standards, despite promises and warnings. But, allowing for all that, some rivers are very good, and the overall trend is probably up as far as gross pollution is concerned.
However, I don't know why, I really can't explain it but I get a sense that there might be some sort of more insidious, slow working, possibly invisible and odourless chemicals that are difficult to trace at work in our rivers now. It may even be just residuals in the silt....but I feel there is something that is causing serious breeding and fry mortality issues, and other such problems. I know the madness that is the EA flood prevention team, and increases in our population and the like, are not helping....but I still feel something is lurking, something that will come out or be admitted to in due course. Mixtures of hormones and other lovelies that are in human urine because of the stupendous levels of birth pills and medications of all sorts that we now take....are obvious candidates...but who knows? As I say, no doubt we shall learn if...or what, when they are ready to tell us
Cheers, Dave.
PS....That'l teach me to be such a long winded old fart...there are several much shorter/better post's in there before me