258
S. M. HAQ, J. Au KHAN, and S. CHUGTAI:
Species of copepods were identified according to GIESBRECHT (1892), SARS (1924 to
1925), MORl (1937), and many others pertinent to the subject. Siphonophores and
chaetognaths were identified with the help of ALVARlNO (1967), TOTTON and BERGMANN
(1965), and SEARS (1953), and where later confirmed by ALVARlNO of the Scripps
Institution of Oceanography, U.S.A.
I. Abundance of Major Groups
The quantitative study of various major groups for the 58 stations used in the cruises
has yielded massive data. The areas covered by each cruise have been divided into sectors,
based on differences in ecological conditions as well as topographical features. The
average number per m 2 of each major group was computed from the values obtained for
all the stations in a particular sector. Table 1 shows the scheme of division into various
Cruise
Cruise I
Oct. 1962
Cruise II
Nov. 1964
Cruise III
March 1967
Cruise IV
March 1968
Table 1. Division of areas into ecological sectors covered by each cruise
Sectors
Slope water
North of Swatch
Swatch
South of Swatch
Shelf
Slope water
Western sector
Eastern sector S. Astola Island
Shelf
Slope water
Stations
61/1- 5, 7, 9, 12
64/1-10,14,15
64/13, 16, 18
64/11,12,17-21
67/1-7,12-14
67/8-11
6717-9
6711-6,10-14
68/1-3
68/4-6
sectors and the stations occupied. On the southern shelf 3 sectors have been established,
i.e. the Swatch, and the areas north and south of it. In general, all other areas were
divided into slope and shelf sectors. The area along the west coast covered in March 1967
is divided into a western sector, represented by stations 6717 to 67/9 south of Astola
Island and an eastern sector represented by all other stations. Figs. 2-7 show the
distribution of the total number of zooplankton organisms and the distribution of biomass
for various cruises. Fig. 8 shows the average values per m 2 of sea surface for each major
group.
Copepods formed the bulk of the zooplankton stock. Comparison between various
sectors shows maximum abundance in October from the slope water region along the
western coast. The second largest abundance was found in the slope water region, but
very low values in March 1968 from the shelf. In March 1967, the highest number was
found in the western sector near Astola Island. Comparison between various sectors
for this month shows very low values on the shelf as well as in the entire eastern sector
including the slope water. In fact, there was a very high concentration of copepods in
the western sector of the slope water region which apparently accounted for high values
of the entire slope water region; this high abundance coincided with a reduced isothermal
S. M. HAQ, J. Au KHAN, and S. CHUGTAI:
Species of copepods were identified according to GIESBRECHT (1892), SARS (1924 to
1925), MORl (1937), and many others pertinent to the subject. Siphonophores and
chaetognaths were identified with the help of ALVARlNO (1967), TOTTON and BERGMANN
(1965), and SEARS (1953), and where later confirmed by ALVARlNO of the Scripps
Institution of Oceanography, U.S.A.
I. Abundance of Major Groups
The quantitative study of various major groups for the 58 stations used in the cruises
has yielded massive data. The areas covered by each cruise have been divided into sectors,
based on differences in ecological conditions as well as topographical features. The
average number per m 2 of each major group was computed from the values obtained for
all the stations in a particular sector. Table 1 shows the scheme of division into various
Cruise
Cruise I
Oct. 1962
Cruise II
Nov. 1964
Cruise III
March 1967
Cruise IV
March 1968
Table 1. Division of areas into ecological sectors covered by each cruise
Sectors
Slope water
North of Swatch
Swatch
South of Swatch
Shelf
Slope water
Western sector
Eastern sector S. Astola Island
Shelf
Slope water
Stations
61/1- 5, 7, 9, 12
64/1-10,14,15
64/13, 16, 18
64/11,12,17-21
67/1-7,12-14
67/8-11
6717-9
6711-6,10-14
68/1-3
68/4-6
sectors and the stations occupied. On the southern shelf 3 sectors have been established,
i.e. the Swatch, and the areas north and south of it. In general, all other areas were
divided into slope and shelf sectors. The area along the west coast covered in March 1967
is divided into a western sector, represented by stations 6717 to 67/9 south of Astola
Island and an eastern sector represented by all other stations. Figs. 2-7 show the
distribution of the total number of zooplankton organisms and the distribution of biomass
for various cruises. Fig. 8 shows the average values per m 2 of sea surface for each major
group.
Copepods formed the bulk of the zooplankton stock. Comparison between various
sectors shows maximum abundance in October from the slope water region along the
western coast. The second largest abundance was found in the slope water region, but
very low values in March 1968 from the shelf. In March 1967, the highest number was
found in the western sector near Astola Island. Comparison between various sectors
for this month shows very low values on the shelf as well as in the entire eastern sector
including the slope water. In fact, there was a very high concentration of copepods in
the western sector of the slope water region which apparently accounted for high values
of the entire slope water region; this high abundance coincided with a reduced isothermal