25 



only fair and right therefore to recognise that the destruction has 

 only been a partial one. All the same, the experience of the season 

 warns us as to the extent the efHuents poured into the Tync are 

 becoming perilous. 



In addition to smolts, kelts, both salmon and trout, were 

 destroj^ed at Newcastle, but the effect of the accumulation of 

 poisonous effluents early in May was interesting in another way, 

 for anadromous migrants were poisoned as well. One marine 

 lamprey was reported, and many elv^ers, the pioneers of the season, 

 were picked up. Young marine fish were included amongst the 

 losses, the presence of which so far up the river is noteworthy. 

 Two flounders were brought to me measuring 8-8 and 11-7 cm. ; 

 but of especial interest were young herring in their first year. Three 

 were brought to the Laboratory on the 19th and 20th of May, 

 measuring 5-6, 5-9 and 7 cm., and at the whitebait stage. On 

 the 24th May specimens of still younger herring, measuring 4 to 

 4-5 cm. in the post-larval phase, were brought from the Gateshead 

 side of the river, with the report that they were Ijing in large 

 numbers on the shore. It is evident that the herring had drifted 

 up with the tide, and had they not been poisoned would have been 

 carried down again with the ebb. The occurrence serves to indicate 

 the long period during which the herring are passive denatant 

 migrants before they become strong enough to become contra- 

 natant. Reasons are given on page 11 for beheving that these 

 post-larval herring have been derived from the spawning at the 

 beginning of this year in the Firth of Forth. 



The experience of the season of 1917 will have to be kept in 

 mind, for apart from sentimental considerations relating to the 

 repute of the river as a salmon river, the cleaning of the Tjne 

 and the tributaries of the Newcastle region ought to be included 

 in a rigorous scheme of town-planning, which it is hoped one day 

 soon will be adopted and carried into effect. The manufacturers 

 and others concerned will have to treat the effluents so as to render 

 them innocuous, and in doing so will probably discover that the 

 by-products have been more than worth the expense. The cities 

 will also have to consider how far it is desirable to treat the sewage 

 so that the river and the tributaries may not continue to be, what 

 they have aheady become, open sewers. 



