Seasonal changes in zooplankton communities in the re-flooded Mesopotamian wetlands, Iraq

Abstract

Non-directional re-flooding of the wetlands in southern Iraq, which were extensively drained during the 1990s, started in 2003. The change in species composition and abundance of rotifer and cladoceran communities together with their abiotic environment were studied for 15 months in the re-flooded wetlands. The re-flooded wetlands were characterized by higher salinity than typical freshwater inland marshes, and some rotifer and cladoceran species were characteristic of the saline, post-reflooding environment. The changes in species composition and abundance of rotifers were mostly seasonal, demonstrated by the cyclic changes in principal component analysis and their positive relationships to water temperature. Al-Huwaiza Marsh is distinguished from the other two marshes (Central and Al-Hammar Marshes) and is characterized by relatively lower and stable salinity, close to neutral pH, near or above saturation DO, and lower SO 4 À2 . These characteristics might explain the differences in recovery processes of zooplankton communities among the three marshes. The Jaccard's similarity index for Cladocera revealed similarity between the two stations of each marsh (in terms of maximum densities recorded); however, this was not mirrored by Rotifera. Al-Huwaiza Marsh stations were very similar to each other, whereas the Al-Hammar and Central Marshes had one station of each very similar to the other station of the other marsh. Cladocera and Rotifera are predominantly freshwater species; Rotifera is more sensitive to water quality changes, particularly salinity, than the Cladocera. The observed seasonal cycles of zooplankton communities might suggest that the system was stabilizing during the study period. However, water supply shortages since 2008 continue to threaten the wetlands.

Diversity and seasonal changes of zooplankton communities in the Shatt Al-Arab River, Basrah, Iraq, with a special reference to Cladocera

“…The northern section of Shatt Al-Arab River is poorly known in terms of zooplankton taxa. This study indicated that that section has less species of Cladocera (23 species) compared to the Marshes (41 species; Salman et al, 2014). Al-Qarooni (2005) reported only 14 species from the southern Marshes, Ajeel (1998) found 23 species in Shatt Al-Arab River.…”

Rotifers diversity at Shatt Al-Arab River and Shatt Al-Basrah canal, South of Iraq, during the abnormal rising of water salinity

“…The monthly largest numbers of genus were (10 and 9) recorded at station 1, 8 at station 1, and 6 at station 3 in different months of the study, Salman et al (2014) found that rotifera showed monthly changes in genus diversity. Station 1 (Al-Asafia) characterized by a suitable environmental conditions for rotifer to occurs in a high numbers of species and genera compared with the other two stations.…”

“…Because of their opportunism and adaptability, rotifers are widely distributed in freshwater planktonic habitats at densities that can exceed 1000 individuals per liter, and if sufficient food is available, occasionally can attain densities from 5000 to >15000 individuals/liter (Gulati et al, 1992;Shao et al, 2001). Ghazi and Ali (2012) investigated the rotifers of Shatt Al-Arab from Qurna to Fao through 12 months and listed 47 taxa and Salman et al (2014) listed 105 species of Rotifera from the Southern Iraqi marshes. Ghazi and Ahmed (2008) studied the abundance and diversity of rotifers in ponds in Garmat Ali region and recorded 26 species.…”

First record of Cyprideis torosa (Jones, 1850) (Crustacea: Ostracoda) in the East of Al-Hammar Marshes, Southern Iraq

“…The study was conducted in eastern Al-Hammar marsh, which is located in the southern part of the Euphrates River in Iraq. This marsh extends from Suq Al-Shuyoukh town in Dhi Qar governorate to Basra governorates, its length is 90 km, its width is 25-30 km, and its depth is 3m (Salman et al, 2014), (Fig. 1).…”