260 
PACIFIC SCIENCE, Vol. XIV, July I960 
TABLE 2 
Growth Shown by Tagged Albacore 
NO. 
DATE OF 
RELEASE 
DATE OF 
RECOVERY 
DAYS 
OUT 
SIZE AT 
RELEASE 
(cm.) 
SIZE AT 
RECOVERY 
(cm.) 
NET 
GAIN 
(cm.) 
GAIN 
PER YEAR 
(cm.) 
1 
10/4/54 
11/28/55 
420 
78.2 
— 
_ 

2 
10/5/54 
1/19/56 
471 
68.0 
105.0 
37.0 
28.7 
3 
10/9/55 
6/24/56 
259 
63.4 
— 
— 
— 
4 
10/17/55 
8/1/56 
288 
59.9 
72.3 
12.4 
15.7 
5 
7/31/56 
7/23/57 
357 
68.4 
78.0 
9.6 
9.8 
6 
8/1/57 
9/17/57 
47 
66.5 
— 
— 
— 
7 
7/22/57 
10/7/57 
77 
65.5 
67.0 
1.5 
7.1 
8 
10/16/55 
11/23/57 
769 
65.1 
94.8 
29.7 
14.1 
9 
11/17/56 
11/17/57 
365 
85.2 
97.5 
12.3 
12.3 
10 
7/23/57 
5/26/58 
287 
78.0 
85.2 
7.2 
9.2 
11 
7/22/57 
6/10/58 
323 
75.0 
— 
— 
— 
12 
7/16/57 
7/11/58 
360 
65.0 
77.3 
12.3 
12.5 
13 
7/16/57 
8/22/58 
402 
75.0 
84.5 
9.5 
8.6 
14 
11/14/56 
8/23/58 
64 7 
79.4 
92.6 
13.2 
7.4 
15 
11/21/56 
7/21/58 
607 
68.6 
86.4 
17.8 
10.7 
A* 
8/11/53 
2/2/54 
176 
84.0 
88.0 
4.0 
8.3 
B* 
8/16/53 
2/23/54 
192 
91.0 
93.0 
2.0 
3.8 
* Fish tagged by the California Department of Fish and Game and reported by Blunt (1954) . 
rapid approximation method by Riffenburgh 3 
for estimating the parameters of the Gompertz 
curve was used. The same paper contains a 
lengthier and more precise method in which the 
estimates converge stochastically to the para- 
meters, but it was felt that the number of data 
available was inadequate to assure convergence. 
Thus, the approximation technique was utilized. 
The method uses three sets of data points: 
3 Riffenburgh, R. H. MS. A new method for esti- 
mating parameters of the Gompertz growth curve. 
University of Hawaii and Pacific Oceanic Fishery In- 
vestigation, U. S. Fish and Wildlife Service, Honolulu. 
Fig. 3. Size-frequency distribution of albacore tagged 
by POFI in the North Pacific, January, 1954- August, 
1957. 
(i, y i), (i + j, y i + i), and (i + k, y i+k ). 
The numerical calculation involved is markedly 
simplified if k = 2 j. In this case, the triplet of 
points having x-values of N + 3, N + 5, and 
N + 7 (Fig. 6) was selected from among the 
set of triplets possessing the property k — 2j; 
these points fall approximately within the por- 
tion of the curve for which there are observed 
data. The corresponding y-values, obtained from 
Walford’s curve, were y 3 = 62.7 cm., y g = 
84.8 cm., and y 7 = 98.2 cm. The estimate of 
the parameter c = 1.43 was obtained by the 
equation: 
Ti +k 
log — 
?i + j 
log — 
yi 
and the estimate of the parameter b — 0.177 by 
the equation: 
Jfi+k 
log — 
JO + i 
log h — • 
c A <r j (c^- 1 ) 
