6G REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The best precaution against this growth is the careful picking out of 

 dead eggs before there is time for the fungus to grow on them, and in 

 case of a serious attack on fry or older fish to treat them with an exterior 

 application of salt, which, while not a cure-all, is very efficacious in 

 cases of fungous diseases, and, if prudently used, a safe remedy for fish 

 that have reached the feeding stage. 



To apply this remedy to fry in the troughs a saturated solution of 

 salt in water is made — that is, the strongest brine that can be made with- 

 out heating the water. The flow of water in the trough to be treated 

 is then stopped, which leaves it from 3 to 4 inches deej), when enough 

 brine is poured in to make the water in the trough about as salt as com- 

 mon sea-water, about 1.028 specific gravity. The fish are left in this 20 

 or 30 minutes, unless they exhibit uneasiness, and then fresh water is 

 turned on. Precaution is taken to dilute the brine with an equal quan- 

 tity of water, to distribute it the whole length of the trough, actively 

 stirring the water to secure an even mixture; and before turning on the 

 usual water sui)ply, a large quantity of fresh water is likewise poured 

 in, distributing it the whole length of the trough and stirring as before, 

 to guard against a too sudden change. 



Such precautions are especially necessary in the application of salt 

 to very young fish. A large number of salmon in the sac stage was 

 once destroyed by pouring in a little brine without stirring it; it ap- 

 X)eared to sink to the bottom and spread out in a layer by itself among 

 the fry, and all exposed to it died. 



ENEMIES OF YOUNa SALMON. 



The young salmon are subject to the attacks of many animals and 

 birds, such as the mink, mole, star- nosed mole, common rat, muskrat, 

 kingfisher, great horned owl, great blue heron, sandi^iper, and fish- 

 hawk, besides frogs and all large fishes. 



At Craig Brook the mink has caused serious loss in the ponds. As 

 a protection some of the ponds are covered with galvanized poultry 

 netting, and traps are kept constantly set in the avenues by which it 

 is apt to approach. The mole burrows through embankments and thus 

 sometimes causes trouble. The star-nosed mole is known to steal dead 

 eggs, and is suspected of taking live ones. The rat sometimes takes 

 young fish from the troughs. The muskrat burrows in embankments 

 and sometimes eats fish. 



The different fish-eating birds occasionally steal fish from the ponds 

 or troughs, but if a careful watch is kept the danger is not great. 

 Frogs may be exceedingly destructive to young salmon, and must be 

 caught out of the fish-ponds. 



To avoid loss from cannibalism among the fishes it is necessary to 

 feed them well and to take great care that no large fish get in among 

 the small ones. 



