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E. D. LE CREN 



Table III. Growth, mortality and production for four sections of a beck stocked with 

 different numbers of trout alevins 



Period I. — 4th May to 4th June 



number of eggs or newly hatched alevins was stocked into each section and 

 the survivors counted and measured after removal by electric-fishing 

 approximately 30, 76 and 114 days after they started to feed at the beginning 

 of May. 



In the first month after feeding there was a correlation between density of 

 stocking and survival and an inverse correlation between density of stocking 

 and growth. In Table III and Fig. 4 the data for four comparable sections 

 are shown. Some other sections (and some cages placed in the beck with 

 their floors covered with gravel to simulate the beck bottom) gave similar 

 relationships between density and growth and survival. 



Biomass of alevins stocked (g/m*) 



Fig. 4. — Production, final biomass and final biomass as a percentage of initial biomass plus 

 production, plotted against initial biomass of alevins for trout in experimental sections 

 of a beck. 



