BUT TO RETURN TO our trout. Apart from the destruction of mature fish, there are causes over which the angler has no control, that seriously interfere with the natural reproduction of the trout. Of these by far the worst is pollution. I need say nothing of the poison from mines and factories that has deleted fish-life in some streams, and left them tenantless. The mischief there is immediate and obvious. But there is a form of pollution more widely spread, more insidious in its action, slower, but no less deadly in its effects. I mean pollution by sewage. Anglers whose visits to their water have been limited to the fishing season, and who have seen fine and well-conditioned trout lying at the mouth of a sewer and evidently enjoying themselves, are apt to say that sewage, unless in great quantities, does no harm to fish. Nor does it, to mature fish; but it is death to the eyed-ova, alevins, and fry. Some interesting experiments lately made in Germany have established the fact that a very small percentage of sewage matter is fatal to salmonidæ in the early stages of their development. It might well be imagined that drainage for purely agricultural purposes would not be injurious to the angler; but in fact it affects him seriously in more ways than one.
A plague of ducks.
For years before the present depression began agricultural authorities had cried aloud for land drainage, as the panacea that was to make the farmer happy and prosperous for evermore. Parliament at length took up the cry, and passed an Act enabling money advanced for this purpose to be charged on the land; and the country soon became a network of drains. Before this time, when heavy rain fell on the land, it percolated the soil, and slowly found its way by devious and undefined channels to the nearest stream. This kept the rivers more uniform in level. It also rendered the meadows through which it flowed spongy, marshy, prolific in sedge, rush, and rank grass—in short, made them a perfect nursery or fly, midge, and insect fit for trout food. Now all is changed. The surface rainwater, rushing through the drains, is discharged into a river a brown seething mass, carrying with it chemical manure, lime, and all sorts of impurity. If this happens when the trout are in the eyed-ova or the alevin stage the year’s hatch is destroyed. Whenever it happens, the river is quickly in flood and quickly again subsides to low-water level, there being no percolation, no trickling runs from its banks to maintain its level. And the fly nursery is no more.
Agricultural depression has added a new terror to the fishing lessee—a plague of ducks. Now that the farmer can no longer thrive on the profits of his land, he relies on his wife’s poultry yard, and this, in the neighbourhood of a river, is apt to contain an inordinate proportion of ducks. It is now not uncommon to see as many as a hundred of these birds heads down, tails up, all busy in picking up their living on a sprawling bed; and the damage they do is incalculable.
