Impact of Tharthar Arm on the Composition and Diversity of Rotifera in Tigris River North of Baghdad, Iraq

Abstract

This study was conducted to evaluate the effects of Tharthar Arm on the composition and diversity of Rotifera in Tigris River. Six sampling sites were selected, two on Tharthar Arm and four along the Tigris River, one before the confluence as a control site and the others downstream of the confluence. Seventy-seven species of Rotifera were identified in Tigris, whereas, 60 in the arm. The results showed that low density of Rotifera in Tharthr Arm decreased the density in Tigris from 239812.4 upstream of the confluence to 223315.5 at immediate downstream of the confluence. It also declined the mean values of richness, evenness and Shannon diversity indices from 5.19, 0.69 and 2.14 bit/Ind., before the confluence to 3.97, 0.73 and 2.00 bit/Ind. below the confluence, respectively. Moreover, the highest similarity value was between sites 1 and 6 reached 83.27%, while the lowest value was between sites 1 and 2 recorded as 60.52%. For constancy index, the highest value was 14 in site 1 and the lowest was 8 in site 2.

Physicochemical Parameters of River Water and their Relation to Zooplankton: A Review

“…Sluss [67] demonstrated that velocity is an important direct physical mechanism that can impact zooplankton densities. growth of rotifers population increased with increasing of flow rates, and conversely with larger microcrustaceans Majeed et al [43] and Thorp and Mantovani [52] indicated that the mean discharge values negatively correlated with rotifer density and positively correlated with crustacean abundance.…”

“…Typically expressed in ppt (part per thousand). Many previous studies indicated that riverine zooplankton affected by salinity, Nguyen et al [41] Majeed et al [42] found that Copepoda density increased with the increasing the salinity whereas, Rotifera density decreased with increasing of salinity [41,43]. Also, Kaya et al [44] showed that zooplankton composition in Zamantı Rive is highly affected by salinity.…”

“…Also, Ishaq and Khan [19] observed that Copepoda negatively correlated with TSS concentrations in the Asan River in India. For Rotifera diversity, Majeed et al [43] indicated that increasing the suspended solids in the Tigris River during the winter season leads to an increase in Rotifera diversity.…”

Effect of AL-Tharthar Canal on the Zooplankton Composition and Diversity in the Tigris River

“…Also, Ostojic´ et al [67] showed that variations in physicochemical characteristics reduced the value of zooplankton similarity index in the Sava River. In this respect, Majeed et al [68] found that the highest value of the similarity index for Rotifera reached 83.27% between two different sites along the Tigris River northern Baghdad City, attributing that to the similarity between the physicochemical factors of both sites. For spatial variation, the most constant zooplankton species were recorded at site 6 whereas, the lowest value was at site 3 on the arm.…”

Using Heavy Metals Pollution Indices for Assessment of Tigris River Water Within Al-Tarmiya City, Northern Baghdad, Iraq

“…The Tigris River is one of the longest transboundary rivers in west Asia; it is also considered one of the two most important sources of freshwater in Iraq, and its flow rate is controlled by a series of dams constructed upstream the river (Majeed et al, 2022a;Haghighi et al, 2023). The Tigris River reaches Baghdad Province about 5 kilometers north of Al-Tajy City (Ali et al, 2012;Majeed et al, 2021;Majeed et al, 2022b). The river running within Baghdad City about 49 km until it leaves the administrative borders of Baghdad Province.…”