FISHES probably at least a dozen would be required to go to an ounce — say two hundred to a pound. It is no unusual thing to take a ton of elvers in a night, that is over a million and three-quarters. It is true that this is only on the spring tides and for a few nights, but it may be said con- fidently that in an average season from twenty to thirty million elvers are caught. The facilities for catching have been greatly increased by the erection of the weirs, yet surprise is sometimes expressed that the supply of eels diminishes. Passing from the division between anadromous and catadromous fish a word should be said on the changes that have been made in the Severn itself so as to render it less fit than formerly for Salmonidce and better adapted for Cyprinidce. Before 1842 the shoals and fords on which fish could spawn began from the point, or perhaps below the point, to which the tide regularly ascended, and continued all the way up the stream. The river was then more fitted for Salmonida than for Cyprinida ; but the improvements required for the navigation have caused all these fords to be dredged out and the river is practically turned into a canal. The result is that there are about twenty miles of canalized river between the head of the tideway and the first ford, all deep water, in no part of which could a salmonoid fish spawn, but in any part of which he could be netted. Further, across the water at intervals are placed four weirs that require a rise in the river for the fish to get over them. This water is now so well adapted for coarse fish that they increase and multiply in it to an unlimited extent, as all netting for fish other than salmon is illegal in the Severn district. The consequence is that certain kinds of fish, not- ably pike and chub, have greatly increased. The increase in the fish food has not been at all in proportion to the increase in numbers, the result being that the fish have largely decreased in size, and although probably in actual numbers there are more fish than there were, the average size has greatly diminished. The lack of food has driven the coarse fish into the tributaries, where they used never to be seen, with the result that they have greatly thrived, and driven the trout higher and higher up the streams so that the area of water now frequented by trout in Worcester- shire is yearly decreasing, and that frequented by coarse fish increasing. The Worcestershire fish are therefore undergoing a rapid change. Probably in the course of this century the anadromous fish will have become if not extinct at least only casual visitors, the catadromous fish will be present in lessened numbers, while the streams will be peopled mainly with Cyprinidce. The occurrence of any specimen of the Salmonidce will be a noteworthy event. As far as can be made out from any existing evidence the fish that have hitherto been found in the Worcestershire rivers were very much the same as at present. A hst of fish, but probably not an exhaustive one, is given in 1678 by the Statute 30 Car. II., c. 9. There it appears that the fish were salmon, trout, pike, barbel, chub and grayling. Salmon is mentioned as ' salmon, salmon marl and salmon peal.' The salmon peal is {Salmo truttd) the sea trout, but what the ' salmon marl ' is it is impossible 133
