?4 SALMONIDJl OF BRlTAIIf. 



-weirs exist in -wliicli there is no free gap. However efficient these passes may be 

 they are not complete cures for the injuries inflicted by the obstructions, for here, 

 except during very high floods, the salmon will often loiter while ascending, and the 

 kelts descending, as if they were hesitating prior to trusting themselves to these 

 unnatural roadways. 



Fish-passes arc constructed of wood, stone, concrete, or iron, and may be 

 classed under such as assist the fish by means of steps or pools to ascend over or 

 even round any obstacle, or else by means of a succession of lochs to pass through 

 the obstruction. But from the year 1830, when Mr. Smith of Deanston invented 

 the first salmon ladder used in this country until the present day, many improve- 

 ments have been made ; but in all it would seem that the most efiective are such 

 as improve a natural passage, while if steps or stairs are employed the gradient 

 should not exceed an incline of 1 in 8. The second class of passes, or such as 

 are intended to assist fish passing through the body of an obstruction, are few in 

 number and scarcely in favour at present.* 



When descendingt seawards, it would appear that the salmon usually pass 

 gradually into the salt water, but a heavy flood sometimes carries weak fish down 

 stream. Many observations have been made that none but kelts ever descend 

 salmon rivers, and I have heard experienced net fishermen in the Teith hold this 

 opinion, as they consider all clean fish will be killed ; but, as I have already 

 observed, if not killed (see page 69) some must descend to the sea before they will 

 be in a condition to spawn, a view confirmed by the experiments made in the 

 United States (see page 79), that salmon in some rivers only breed in alternate 

 years. The pinks or smolts keep to the sides of the river, but having once 

 arrived at the tideway would seem to seek the deep water, to return again 

 at a future date as breeding grilse. 



witness to the conclusion that an open river is the best for all, and that a recurrence to the 

 ancient and clearly pronounced policy of the country by the removal of obstructions from the 

 water is the sure and only road to the restoration of the fisheries." 



* The reader must be referred to works on " fish culture " for full details as to fish-passes. 



f Mr. Stephen deposed, before the Committee on the Sahnon Fisheries, in 1824, that, " Our 

 cruives in the River Don are so constructed that salmon of 10 lb. weight can at all times go up, 

 but none can descend past the cruives. We fish generally in the pools above the cruives, and if 

 the unspawned salmon returned again down the river we would undoubtedly catch them there, 

 which is never the case. They are never seen to descend the river, except as kelts, after having 

 spawned." 



James HaUiday deposed that salmon which enter rivers at any period, but not for spawning, 

 would return again to the sea at times, were such return not cut off by want of water on the 

 shallows ; but if floods occur, they descend. He continued, respecting the Sand Pool in the 

 Annan : " Although we had fished this pool quite clean of fish before the rain came on, yet 

 whenever the rain did come on we then continued fishing constantly, until the water rose so high 

 that we could not manage it, and we got the salmon and grilses coming down the river all the 

 time into the pool ; some of them had the appearance of having laid long in the water, and were 

 very much exhausted — quite changed in the colour, as if they had hung in a smoky chimney for 

 some time ; others were very red in the skin, by having been in the fresh water for some time. I 

 have known us take 103 fish in one night in that pool after the rain commenced, although we had 

 fished it clean immediately before. Our opinion was that the fish came down from the river 

 above, out of the rooky waters of the Bridekirk, Loos, and Hoddam. The reason for fishing the 

 pool at that particular time, was that the river at the foot of it parted into three small branches, 

 and the pool itself was very deep. When the water was rising the fish could not find their way 

 so readily down there, and they turned into the deep pool, and we kept drawing constantly as 

 long as we could manage the water." 



Mr. Buist (Quarterly Journal of Agriculture, 1832, p. 624), criticizing Hogg's paper, 

 remarked: — "He, however, is wrong in stating that clean salmon return to the sea in great 

 numbers from Glenlyon, on the upper part of the Tay, without having spawned. After the 

 salmon leaves the tideway of the river, it pushes upwards to the smaller rivers, and when these 

 subside, it may return downwards to the pools in the larger rivers. We seldom or never see 

 a salmon that has been long in the fresh water return unspawned through the bridge at Perth, 

 which is nearly about the boundary of the tideway. Men are stationed on the bridge to 

 observe every fish that passes in the ordinary state of the river. Below that, among the many 

 thousands of salmon that I have seen taken, few or none bore the appearance of having been 

 long in the fresh water. While many hundreds of foul or newly-spawned fish are hauled 

 ashore every year, we get none with milts or roes returning to the sea, or that have the 

 emaciated appearance, and maggots in the gills which characterize the fish that are found 

 far up out of the tideway and have been long in the fresh water." 



