Fish Population Dynamic and Stock Assessment (2+1)

Solution

To calculate (T₁) and T₂

(i) Calculation of T₁ and T₂

t - t_o = $$\log e({1-{Lt \over {L\infty}})$$

L$$\infty$$ = 23.1, K = 0.59

(ii) $$\Delta t$$  is calculated directly as T2-T1

(iii) Calculate log e $$N \over {\Delta t}$$ 

(iv) The mean relative age is derived as $${T_1+T_2}\over 2$$

(v) Draw a graph by plotting mean relative age as X variable, log_e $$N\over{\Delta t}$$ as Y variable

(vi) Estimate Z from descending right arm of catch curve. For estimation of Z, do not use data pertaining to ascending part of curve and do not use the length group whose value are close to L$$\infty$$