The Simple Calculation Method of Oxygen Consumption by Aquatic Animals in Water Tank―I Water volume constant

摘要

While the calculation method of oxygen consumption by aquatic animals developed by one of the authors (Morooka, 1967) requires a considerably troublesome procedure, a simpler method has been devised. The former method was derived from the equation Dt=(Da-Kf/K)e-Kt+Kf/K integrated from dD/dt=Kf-KD, (D……deficit rate of oxygen, t……time, Kf……decreasing rate of dissolved oxygen by animals, K……aeration constant) but the simple method is derived from the differential equation dD/dt=Kf-KD. Plotting dD/dt value as ordinate and corresponding D value as abscissa, the tangent of regression line becomes equal to K, and the point of intersection of Y-axis and the regression line becomes equal to Kf, provided that dD/dt is approximately equal to (Dn+1-Dn)/(tn+1-tn)instead of lim (Dn+1-Dn)/ (tn+1-t1)and the corresponding D is nearly equal to (Dn+1-Dn)/2. Then substitu-ting the Kf value in Kc=(Kf・V・Sat.O2)/BW(Kc……oxygen consumption, V……water volume), Kc value is obtained.