REPORT OF STATE BOARD OF FISH COMMISSIONERS. 



28 



arrangements to handle this increased run of tish, and notitied us early in the season 

 that he would in all probability take about 30,000,000 eggs from the summer run at 

 Baird station on the McCloud River. Our hatchery at this time was undergoing much 

 needed repairs, which the special appropriation of the Legislature allowed us to make. 

 The work on the troughs was rushed so as to have them in readiness for the eggs. The 

 capacity of Sisson hatchery at this time was H),(MM),0()0 eggs during the hatching perioil 

 and 8,000,000 embryos during the period of the absorption of tiie yolk sac. As the desire 

 of the Board was to hatch all the salmon eggs furnished by tlie United States Bureau of 

 Fisheries stations, I planned a system of troughs to be l)uilt over the ten imrseries or 

 rearing ponds, into which the embryo salmon could be put as fast as they hatched. 

 These troughs were made on the same plan as the regular hatching troughs. Two of 

 them were placed side by side on supi)orts t)ver the nurseries, about ten inches from the 

 surface of the water. They extended half way the length of the nursery. The water 



SISSON HATCHERY. 

 Sectional view of nursery ponds, showing arraiiKenieiit of hrttoliiiig tronghs. 



for the nursery was run through the troughs and discharged from the end of the trough 

 into the center of the nursery. The embryos were kept in these troughs until they had 

 partially absorbed the sac and the pigment had taken the place of the mucus in the 

 epidermis. They were then placed in the nursery underneath the troughs. The danger 

 of smothering is passed when they arrive at this stage. This is one of the hardest things 

 to overcome in rearing the embryos in large numbers outside of the regular hatching 

 troughs. This method of handling them proved to be a great success. The embryos 

 were released from the troughs into the nurseries at the proper age, and the troughs 

 refilled from the hatchery with another lot that had just hatched. After the embryos 

 had attained the swimming stage, they were allowed to escape from the nurseries into 

 the canal or ditch connecting the hatchery water system with Cold Creek and from 

 there pass into the main Sacramento River. The loss in rearing with this system was 

 very small after the embryos were turned from the troughs into the nursery. The 

 bottoms of the nurseries are built on an elevation, tluis making them easy to clean. 



