24 FISH FARMING I 



you take another glance at the photographs of natural spawn- 

 ing grounds, you will see that in ealch case the banks of the, 

 river axe well wooded. If this shade does not exist in con- 

 nection with artificially formed redds, it must be provided, 

 either by planting trees or by placing covers over the redds. 

 I deal with the subject of enemies to fish eggs in another chap- 

 ter ; but I may say here that protection from birds is pretty 

 well sure to be necessary. The best plan is to enclose the 

 redds entirely with either tanned netting OT light galvan- 

 ised wire netting ; the top frame may, where necessary, serve 

 the purpose of a shade also. It will frequently happen that 

 one or two valuable fish will spawn before the bulk of fish ar6 

 on the redds, and it becomes necessary to protect these very 

 early eggs from being up-rooted by other later, yet sufficiently 

 desirable, spawners. This is best done by an arrangement of 

 wire-netting framed on galvanised iron frames (after the man- 

 ner of very large pzarprctectors), but care must be exercised 

 that the netting does not get clogged with debris, and so pre- 

 vent a proper current of water from flowing over the eggs. 

 Ova may be, and advisedly is, protected in a similar manner 

 in the open in big waters, but it is, of course, far more easily 

 and effectually protected on properly controlled redds. 



Should the fishery be short of mature spawners, or should 

 the introduction of new blood be deemed advisable, fully* 

 eyed ova may be sown on the redds; indeed, this is a most 

 valuable method of improving an existing fishery where there 

 are protected redds'. The gravel should be raked level in a 

 suitable spot, and the eyed eggs sown very thinly over it, and 

 then left to hatch. In this way you will get a much larger 

 percentage hatched out than if the eggs were naturally 

 spawned, principally because the ova is delivered almost on 

 the point of hatching, and consequently has to run the gaunt- 

 let of its enemies for a few days only instead of for nearly three 

 months. This ova is also quite easily and very advantageously 

 handled in simple outside hatcheries, which will be described 

 in their proper place. Caution is necessary in connection with 

 the purchase of fully-eyed ova. Obtain the eggs from some tho 



