International Journal of Marine Science, 2017, Vol.7, No.8, 67-75
68
feeding of many fish, and good sources for fishing and important outlets for the Iraqi territorial waters. Therefore,
the present study aims to estimate the zooplankton production in North West Arabian Gulf, identify the
environmental characteristics and to study some characteristics of biological organisms by means of the biomass
of zooplankton
.
In addition to that the study aims to give basic information about the diversity and occurrence of
the zooplankton from 7 stations in Iraqi marine water at the period of the peak time.
1 Materials and Methods
1.1 Sample collection
Seven stations were selected in various localities in North West Arabian Gulf. Shatt Al-Arab estuary represented
in St. 1 Al-Faw located in the Shatt Al-Arab River, before the flow in the Arabian Gulf (29
°
59
׳
20.06
״
N
48
°
28
׳
02.22
״
E), St. 2 Ras Al-Bisha located in the end of Shatt Al-Arab River (29
°
56
׳
3.20
״
N 48
°
35
׳
45.98
״
E), St. 3
Al-Musab, located in the beginning of the Arabian Gulf (29
°
50
׳
54.8
״
N 48
°
4933.1
״
E), St. 4, 5 and 6 at Khour
Abdulla located between Al-Faw peninsula and Warbah and
slands }St. 4 Buoy 5 located (29
°
46
׳
57.6
״
N
48
°
34
׳
15.4
״
E), St. 5 Buoy 13 located (29
°
50
׳
26.4
״
N 48
°
25
׳
49.7
״
E), St. 6 Buoy 29 located (29
°
59
׳
54.8
״
N
48
°
12
׳
33.1
״
E){ and St. 7 Umm Qaser Port located (29
°
59
׳
54.00
״
N 47
°
59
׳
30.37
״
E) (Figure 1). The nature of these
stations is quite different from each other, plankton net of 120 micron mish-size and 40 cm mouth diameter was
towed behind a boat for 15 min. A flow-meter was mounted at the mouth of the net to determine the volume of
water filtered by net (DeBernardi, 1984). Water temperatures were recorded to the nearest 0.1°C. Salinity
determinations were carried out immediately with a digital salinometer M.C.5 type Salinity Temperature Bridge.
Samples were preserved in 4% formalin immediately after towing, while those used for biomass measurements,
were deep-freezed without fixation.
Figure 1 Map of low Mesopotamia showing the sampling stations at North West Arabian Gulf
In the laboratory, the samples were poured into a graduated vessel, and diluted if densely populated. Then a 10 ml
subsample was taken. The sample was placed in a Bogorov chamber, examined and counted under a
stereomicroscope. This procedure was repeated for 3 times, and then the whole sample was examined for the rare
species.
1.2 Biomass of zooplankton
1.2.1 Displacement volume
The volume of water displacement of zooplankton was measured for all samples. The samples were put in the
volumetric flask 500 ml and completed the volume to the final mark by the addition of water, then the sample was
filtered through a net of a mish-size less than that used for sample collection, in another volumetric flask (500 ml),
the volume then was completed to the mark.
