In the Gulf of Oman 52 trawl stations were taken in the mesopelagic fish layers in 1979 and 74 in 1981. (See Annex 3 for details.) In 1979 the mean catch rate was 200 kg/h, 6% of the stations gave catch rates higher than 500 kg/h, and 2% higher than 1000 kg/h (Table 9).
In 1981 the mean catch rate was about 1000 kg/h and 44% and 36% of the stations gave catch rates higher than 500 kg/h and 1000 kg/h respectively. Seven percent gave more than 6000 kg/h (Table 9).
Most of the high catch rates were obtained in the shallow day layer (D I), but also nearly 20% of the hauls in the surface layer (N I) during night gave catch rates higher than 1000 kg/h.
In the Gulf of Aden 28 and 23 trawl stations were taken in the mesopelagic fish layers in 1979 and 1981 respectively. The mean catch rates were very low (40 and 60 kg/h) and no hauls gave catch rates higher than 500 kg/h (Table 9).
Table 9. Distribution of catch rates during the cruises in 1979 and 1981.
|
Year |
Type of layer
|
Catch rate in kg/h |
|||||||
|
Area |
<50 |
50 |
500 |
1000 |
2000 |
4000 |
6000 |
³ 8000 |
|
|
1979 |
|
|
499 |
999 |
1999 |
3999 |
5999 |
7999 |
|
|
Gulf of Oman |
D I |
|
15 |
1 |
1 |
|
|
|
|
|
D II |
5 |
6 |
|
|
|
|
|
|
|
|
N I |
2 |
19 |
1 |
|
|
|
|
|
|
|
N II |
1 |
2 |
|
|
|
|
|
|
|
|
Gulf of Aden |
D I |
1 |
|
|
|
|
|
|
|
|
D II |
15 |
1 |
|
|
|
|
|
|
|
|
N I |
6 |
3 |
|
|
|
|
|
|
|
|
N II |
1 |
1 |
|
|
|
|
|
|
|
|
1981 |
|
|
|
|
|
|
|
|
|
|
Gulf of Oman |
D I |
|
4 |
2 |
8 |
8 |
3 |
4 |
1 |
|
D II |
2 |
12 |
|
|
|
|
|
|
|
|
N I |
1 |
16 |
3 |
1 |
2 |
|
|
|
|
|
N II |
|
7 |
1 |
|
|
|
|
|
|
|
Gulf of Aden |
D I |
2 |
2 |
|
|
|
|
|
|
|
D II |
6 |
3 |
|
|
|
|
|
|
|
|
N I |
4 |
6 |
|
|
|
|
|
|
|
|
N II |
|
|
|
|
|
|
|
|
|
