REPORT OF STATK JJOAKI) OF Fi.SII COMMISSIONKKS. 49 



sui)ply was added to the lakes that were stocked in 1895, but we reserved 

 3,000 at our Sisson hatchery for tlie purpose of studying their develop- 

 ment and for use as breeders. 



SLAG. 



We are pleased to report a total absence of slag in the Sacramento 

 Hiver. The Mountain Copper Company at Keswick has' not only faith- 

 fully carried out its agreement with us in regard to making extensive 

 changes and improvements in its methods of handling slag, which 

 involved an outlay of approximately $30,000, l)ut it has since main- 

 tained its i)lant in such shape that slag does not reach tlie river. As a 

 result, catfish, striped bass, and shad are found in considerable numbers 

 above Redding and pass the point at which the slag formerly entered 

 the river. Due credit for this improved condition has been given to the 

 State Board of Fish Commissioners by the newspapers published in the 

 upper Sacramento Valley, as well as by the people living along the banks 

 of the river, who have been enabled to add something to their food 

 supply and much to their sport by the increased runs of fish. 



FISH-LADDERS. 



Since our last report was made, a great many complaints have been 

 investigated regarding defective and inefhcient fish-ladders, and many 

 new ladders and fishways have been constructed. There are still in 

 existence a number of old fish-ladders constructed in accordance with 

 plans that were furnished many years ago. Experience has taught us 

 much in regard to the manner of construction and the proper location 

 of tishways. Wherever it has been possible we have cut a " run round '' 

 in the solid rock or earth around one end of the dam. We have learned 

 that fishways which approach natural conditions as nearly as possible 

 are more readily used by the fish than anything of timber construction. 

 They have also the advantage of being permanent. Those constructed 

 of timber, unless they are carefully watched and a proper supply of 

 water is maintained, deteriorate rapidly and become so weakened that 

 an unusual rise of water is apt to carry them away and leave a dam 

 impassable for another season. 



Among the more important fishways that have been constructed in 

 the past two years are two on the Merced River (one in Merced County 

 and the other in Mariposa County), and three on the Stanislaus River 

 (the first at Knight's Ferry, the second at Six-Mile Bar, and the third 

 at Melones, Calaveras County). Certain improvements are now under 

 way to make the one at Melones more efficient. In Sonoma County, on 

 Big Sulphur Creek, and in Alpine County, on the Carson River, fish- 

 ways have also been constructed. 

 4 — FC 



