(7.4)
The data in the following table represent the mean length (cm) of the individuals at the beginning of the age (years), obtained from direct age reading of individuals of the stock of anglerfish, Lophius budegassa, (Div. VIIIc and IXa), Section 8.7.
t |
L_{t} |
t |
L_{t} |
1 |
9.2 |
7 |
44.4 |
2 |
16.5 |
8 |
49.0 |
3 |
22.9 |
9 |
52.3 |
4 |
28.8 |
10 |
55.0 |
5 |
34.7 |
11 |
60.8 |
6 |
38.6 |
12 |
63.4 |
GROUP I
1. Represent graphically the values of L_{t} against t.
2. Estimate the growth parameters K, L_{∞} and t_{0} for the Bertalanffy growth model using a non-linear regression model.
3. Estimate the values of L_{t} corresponding to given values of t and mark on a graph the observed values and the estimate curve. Comment on the adjustment.
4. Compare the results obtained in the previous questions with the values of the parameters given in Section 8.7.
GROUP II
Using the data on spawning biomass and on recruitments of hake, presented in Section 8.12, estimate the parameters of the Beverton and Holt, Ricker, Deriso and Shepherd S-R models.
1. Compare the obtained values with those presented in Section 8.12.