Resource Ecology & Fisheries Management (REFM) Division
Resource Ecology & Ecosystem Modeling (REEM) Program
Fish Stomach Collection and Lab Analysis
During January through December 2008, fisheries observers returned 152 stomach samples to AFSC laboratories, and AFSC scientists collected 261 stomach samples from the eastern Bering Sea. In the Gulf of Alaska, 1,920 stomachs were collected during a mesopelagic survey and, in the Aleutian Islands region, 240 stomachs were collected on a survey conducted by the REFM Division’s Fisheries Interaction Team. In the laboratory, 1,428 Bering Sea and 317 Gulf of Alaska stomach samples were analyzed. A total of 7,476 records were added to the groundfish food habits database.
By Troy Buckley, Geoff Lang, and Mei-Sun Yang
Resource Ecology
Five common large sculpin species inhabiting the eastern Bering Sea and Aleutian Islands are being investigated for life history information. The age and growth portion of the study is concluding, with over 2,600 otoliths aged from samples collected during regional groundfish bottom trawl surveys. Results from the yellow Irish lord (Hemilepidotus jordani) and warty sculpin (Myoxocephalus verrucosus) were presented at the North Pacific Research Board (NPRB) Science Symposium held in Anchorage in January 2008 (Table 1 below). Age and growth analysis of bigmouth sculpin (Hemitripterus bolini; n = 198), plain sculpin (Myoxocephalus jaok; n = 788), and great sculpin samples (Myoxocephalus polycanthocephalus; n = 500+) is being completed. Samples collected by fisheries observers aboard vessels operating in the eastern Bering Sea will add to the total.
By Todd TenBrink
Table 1. Estimates of the von Bertalanffy growth parameters
for recently aged yellow Irish lord (YIL) and warty sculpin (WTY), by region
(eastern Bering Sea, EBS; and Aleutian Islands, AI) and sex. Age is the
maximum age estimated, r2 is the coefficient of determination, and n is
the sample size. Asymptotic standard errors are shown in parentheses below
each parameter. |
Species |
Region |
Sex |
Age |
L ∞ |
K |
t 0 |
r 2 |
n |
YIL |
EBS |
M |
24 |
468.1
(10.86) |
0.257
(0.029) |
-0.070
(0.311) |
0.81 |
140 |
YIL |
EBS |
F |
28 |
420.6
(4.35) |
0.295
(0.019) |
-0.022
(0.198) |
0.83 |
246 |
YIL |
AI |
M |
20 |
521.7
(16.99) |
0.147
(0.018) |
-0.851
(0.429) |
0.84 |
160 |
YIL
| AI |
F |
26 |
441.6
(7.59) |
0.171
(0.015) |
-1.258
(0.393) |
0.79 |
238 |
WTY |
EBS |
M |
15 |
433.5
(11.04) |
0.362
(0.059) |
0.039
(0.455) |
0.50 |
267 |
WTY |
EBS |
F |
18 |
537.0
(7.43) |
0.259
(0.022) |
-0.089
(0.283) |
0.76 |
415 |
|
|