i)o 



3G 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



[70] 



ponds than tbey can accommodate to any advantage. In order to cor- 

 rect this, the ratio of fish per hectare will have to be as follows : 



Ponds. 



Raising ponds of the first class. . . 

 Kaisintr ponds of the second class 

 Stock ponds (one _vears' course).. 

 Stock ponds (two "years' course) .. 



Number of fish. 



Minimam. Average. Maximom 



300 



200 



130 



6U 



450 



30O 



180 



90 



600 

 400 

 240 

 120 



Which would give for a total pond area of 100 hectares, reserving 

 6 hectares for winter ponds, the following ratio : 



Ponds. 



Raising ponds of the first class. . . 

 Rai.sing ponds of the second class 

 Stock ponds (two year's course) . . 



do 



stock ponds (one year's course) . . . 



Number offish. 



Minimum. Average, i Maximum. 



3,600 

 3, 600 

 3,600 

 3,600 

 3,600 



5,400 

 5,400 

 5,400 

 5,400 

 5,400 



7,200 

 7,200 

 7,200 

 7.200 

 7,200 



The above figures nuist be considered the best and most rational. To 

 these should be added the so-called "excess," which, however, need not 

 be calculated heie, as it will generally be destroyed during summer, and 

 will therefore not burden the ponds. In order to neutralize the unavoid- 

 able losses by transportation, wintering, fish of prey, birds of prey, «&c., 

 as well as the cases of death which will necessarily occur even on the 

 best-regulated farms, a larger number of fish than the ponds are entitled 

 to are ])laced in them, and this excess over the normal figures is gener- 

 ally determined by the known or estimated loss in former' years, or on 

 other pond farms. 



According to Krafft* the average losses are : In spawning i^onds, 12 

 to 14 i)er cent; in raising ponds of the first class, 10 per cent; of the 

 second class, 7 per cent; in stock ponds, 2 to 8 per cent. 



That these losses will in many cases be much greater may be seen 

 from the statistics of the Peitz farm given above. According to Horak, t 

 the average losses are : Of small two years' fish, 13 to 14 per cent ; me- 

 dium two years' fish, 13 to 14 per cent ; large two years' fish, 10 per 

 cent ; three years' fish, 6 to 7 per cent ; four years' fish, 3 to 4 per cent. 



With a view to expedite matters, and also to avoid any unnecessary 

 handling of the fish, the young fry are not counted, but measured, for 

 which purpose a measure holding GO to 100 is used. Different measures 

 should be used for the different kinds of young fish, and on large pond 

 farms it will generally be found necessary to use three different meas- 



* Dr. KraflFt, Landu-irthscliaft. 

 t Horak, Tekhicirthschaft, 1869. 



