International Journal of Marine Science 2016, Vol.6, No.58, 1-8
1
Research Article Open Access
Seasonal Variations of Zooplankton Abundance in Shatt Al-Arab River,
Southern Iraq
Shaker G. Ajeel
Department of Marine Biology, Marine Science Centre, University of Basrah, Iraq
Corresponding author email
International Journal of Marine Science 2016, Vol.6, No.58 doi
Received: 16 Dec., 2016
Accepted: 27 Dec., 2016
Published: 27 Dec., 2016
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Ajeel S.G., 2016, Seasonal Variations of Zooplankton Abundance in Shatt Al-Arab River, Southern Iraq, International Journal of Marine Science, 6(58): 1-8
(doi
Abstract
Zooplankton samples were collected seasonally from three stations in the Shatt Al-Arab River southern Iraq by Plankton
net (0.085 mm mesh-size and 40 cm mouth aperture) during 2013. Physical and chemical parameters of the water were studied such
as, water temperature, salinity, pH, dissolved oxygen, TDS and Turbidity. The population density of zooplankton ranged between
253 ind./m
3
at second station (Abu Al-Khasib) to 69223 ind./m
3
at third station (Al-Faw) in winter. The important groups of
zooplankton in the study area were Copepoda (56.1%), then Cirripede larvae (19.5%) and Cladocera (12.4%).
Keywords
Zooplankton; Density; Distribution; Shatt Al-Arab River; Basrah
Introduction
Shatt Al-Arab River is located in the southeastern part of Iraq at latitude 31° 00ʹ 15ʺ longitude 47° 26ʹ 35ʺ at the
confluence of the Tigris and Euphrates region and extends until the estuary in the Arabian Gulf at latitude 31° 53ʹ
28ʺ longitude 47° 39ʹ 50ʺ distance of 204 kilometers (Al-Mansouri, 1996).
Zooplanktons are the links in the food web between phytoplankton and higher animals such as fishes and shrimps.
Many species are herbivorous grazers, although there are also numerous carnivorous predators. Zooplankton are
generally small, with little ability or inability to swim against the currents. They are often divided by size, such
that meso-zooplankton is 0.2 -20 mm in size and macro-zooplankton are 2-20 cm in size. Many species of fish and
commercially-important invertebrates have larval stages and they are members of the zooplankton for at least part
of their lives (Sieburth et al., 1978). The zooplankton determines the quantum of fish stock. The failure of fishery
resources is attributed to the reduced copepod (zooplankton) population (Stottrup, 2000).
The studies on zooplankton in Iraq are very few. The first study was carried out by Gurney (1921), which included
the study and classification of crustaceans of the region between the estuaries of the Shatt Al-Arab to the city of
Amara on the Tigris River, and found 77 species belonging to different groups, including Rotifera, Cladocera,
Copepoda, Ostracoda and Phyllopoda. Mohammad (1965) collected and classified the species of Cladocera from
central and southern Iraq, included a study of the Shatt Al-Arab area from the estuary in Khour Al-Amaya to
Qurna, and he found that there are differences between species in the estuary and the other regions.
Salman et al. (1986) explained the seasonal variations of the zooplankton in the Shatt Al-Arab, they founds that
Cladocera constitute 68% of zooplankton which are followed in importance Copepoda. In Abdul-Hussein et al.
(1989) described 11 species of zooplankton belonging to 5 genera of Rotifers in the northern part of the Shatt
Al-Arab. Al-Zubaidi and Salman (2001) study the distribution of zooplankton in the estuary of the Shatt Al-Arab
north-west Arabian Gulf, they said the group of Cladocera constitute 58% of the zooplankton in the Shatt al-Arab,
followed by Copepoda 27%, and while in the estuary of the Shatt al-Arab Copepoda is prevalent. While Hammadi,
(2010) studied the density of zooplankton in Shatt Al-Arab and found it ranged between 1360 and 836310 ind./m
3
.
Then Morad (2011) investigated the seasonally changes of the zooplankton in Shatt Al-Arab River, its ranged
