Pollution of Our RiversCategory: Land + People
By J. W. Kempster
The greatest problem that many fishery boards have to contend with is pollution. As much is known and has been written on the subject of pollution, both in official Government reports and in the different district fishery board reports, as well as in the Press, as would, if collected, fill a bulky volume.
Some of the rivers most suited for salmon and sea trout’ are so polluted as to be practically denuded of these fish, which are prevented from ascending from the sea to their spawning grounds on the upper reaches by the poisoned and de-oxygenated state of the water in the lower reaches. This is due to the vast quantities of sewage and trade effluents which they contain. May to September are usually the five critical months where pollution is concerned, owing to the greater possibility of low water occurring then, though where there are beet sugar factories October and November are the worst months; but much depends upon the amount and distribution of the rainfall. A flush after a dry spell in summer is especially dangerous. There is, however, a great difference in the degree of pollution in various rivers, ranging from almost n i 1 in many of the Highlands streams and such well-preserved chalk streams as the Test and It- chen, where pollution has been successfully kept in check, to — at the other end of the scale — such industrialized rivers as the Tyne, Tees, and Wear; which in certain parts are little more than open sewers.
In the good old days the term “wholesome” was applied to reasonably pure river water, and disputes as to whether streams were wholesome were judicially decided by evidence as to whether cattle drank there or not. This criterion was a fairly acid test, as animals are keenly perceptive of any drink or food that is even slightly adulterated, and are less likely to be biased than their human owners. It was a more severe criterion than one based on the presence of fish that manage to survive in water that would not appeal to cattle unless particularly thirsty.
From Our Rivers, Lnd, 1948.