648 EELS IN WATER PIPES AND THEIR MIGRATION. BISHOP. 



Whether or not the quality of the water will be affected 

 adversely by keeping all the eels out of the lake is to me an open 

 question. The eel is well known to be a great scavenger ; but on 

 this subject I have not secui^ed sufficient data to fonn an 

 opinion. 



Discussion. 



F. W. W. DoANE. — The eel nuisance has been a most per- 

 plexing j^roblem for every superintendent of a water system. 

 It is at times very difficult to account for their presence in 

 pipes. There is no doubt in the mind of the writer that eels 

 will climb over a screen projecting from eighteen inches to two 

 feet above the water. Tractes of eels have been noted on the top 

 of the screens in the gate-houses, and on one occasion an eel was 

 caught in an effort to surmount the obstructina; screens. The 

 carelessness of a gate-keeper sometimes permits their entrance 

 through a small hole worn or torn in the screen or where the 

 corner of the screen frame unprotected by metal has become 

 worn. In the Halifax screen chambers there are two sets of 

 grooves for screens separated only by a thin angle-iron. It was 

 suspected that eels got in w^hile the screens were being chang- 

 ed, consequently a batten was placed on the back of the lower 

 front screen, at the bottom edge so that the space between the 

 two sets of screens w^as completely filled. By always putting in 

 the new screen.^ before removing the old set, there is no oppor- 

 tunity for eels to get between them. 



Anguilla vulgaris is supposed to be long 1^/ed, one authentic 

 instance being recorded of an Cel which was at least thirty-one 

 years old. 



There is no doubt of the ability of eels to travel over land. 

 On more than one occasion Halifax water department officials 

 have seen them, when thrown out of a trench or stream (near 

 the lakes), start for the lake. 



When migrating, no ordinary obstacle seems to stop them. 

 It is claimed that they have been known to cross from one water 

 to another by ascending a branch of a tree hanging in the water 



