FORTH DISTRICT 39 



taken in the upper Teith, in the Campbell Pool at Callander. 

 An arrangement has now been come to by which all the nettings 

 are pooled and fished under a combined system so that a certain 

 amount of benefit may result from the absence of competition. 

 It is certainly the case that the netting is not now so heavy as 

 it used to be. Some such arrangement was very desirable 

 because of the serious influence which the gross pollutions are 

 having on the stock of fish. These pollutions tend rather to 

 increase, while the volume of water allowed to descend tends 

 to diminish. The result is seen in the collection of poisonous 

 sludge in the "links of Forth" below Stirling. In summer 

 when the rivers run low the current is insufficient to carry off 

 the deleterious matter, and when a strong stream tide sets in 

 up the channel of the estuary the sludge is stirred up, the 

 poisonous gases are given off, and large numbers of fish 

 die. Deaths now occur in this way every year, and in dry 

 summers every fish present in the estuary at the time of 

 stream tides dies. In 1920, which was exceptionally wet, it 

 was estimated that more than a thousand fish were killed 

 by the pollutions. 



In the particulars of netting which I have had the 

 opportunity of seeing, the decline of grilse is specially notice- 

 able. The Forth, like the larger river districts on each side of 

 it; used to be well supplied with grilse. I find the average 

 take for the twelve years 1907-1918 was 2,140 grilse. The 

 year 1920 produced 459. At the same time, 1919 was a season 

 with a remarkable run of fish, and if the deaths from pollution 

 had not been very numerous would probably have yielded an 

 unusual total. Much pollution is allowed to enter from the 

 town of Stirling, where little is done by way of purification, 

 and about half way down to Alloa the river Devon enters from 

 the left, which in the past has more than once done serious 

 damage in destroying salmon. The Devon is used by dis- 

 tilleries, and on one occasion some 347 fish were found dead. 

 The smell which rises from the mud at the mouth of this stream, 

 at low tide, has seemed to me to be enough to kill a man let 

 alone salmon. The Carron, which enters the estuary at 

 Grangemouth after flowing through a region of iron works, 

 and which in early days was a salmon river, is now reduced 

 to a state beyond description. 



