Effect of Artificial Enrichments and Inherent Production Capacity on the Fish Production in Taoyuan Reservoirs

Abstract

To determine the function relationship between fish yield and artificial enrichments, we have analyzed, primarily by the multiple regression methods, the data from Taoyuan Serviceman of Fish Propagation Administration. The independent variables were size of reservoirs, inherent production capacity, amount of super phosphate, night-soil, chicken-dung and grass. The dependent variables are the yields of silver carp, crucian carp, common carp, mud carp, bighead, grass carp, perch, catfish and total fish yield. The average of the total fish yield in the 44 reservoirs was 1557kg/ha/yr. The correlation between the total fish yield and inherent production capacity, and the four enrichments was significant at 1% level. The best equation to predict the total fish yield(Y)for any reservoirs is calculated to be Y=296.91+0.547X1+0.003X2+0.051X3, where X1 is inherent production capacity, X2 is night-soil and X3 is chicken dung, all variables in kg/ha/year. The equation indicates that84% of the variability in total fish yield of which 45% is due to inherent production capacity, 26% to night-soil and 13% to chicken dung.