This study was done to find the effect of Tigris-Therthar channel on the water quality of Tigris River to face the climate change which causes decreasing in water resources, in addition to decreasing in its quality. Nine stations were chosen located on Tigris River, Tigris-Therthar channel, Groundwater, and Therthar lake. The results indicated that the TDS increased in summer season, and the effect of Tigris-Therthar cannel was limited, also the effect of groundwater was limited, but there was an indication refers of possibility of increasing these effects on the quality of water. The study recommends observing the Tigris River through a programme to identify any change in water in future.

Benthic   invertebrates'   diversity   and    some  physical    a:1d

chemical characteristics in Lower Zab tributary and Tigris River were studied.  Month l y samples  were col l ected  from  November  2001 to October 2002.

The rt:sLllts of the present study showed  the turbidity iu Tigris river

before the confluence to be higher (34.4 NTU) compared to the other stations.  Mean salinity was greater in Lower Zab tributary (0.33 %) compared to that in the river.  Lower Zab tJibutary and Tigris River were good in Oxygen content, and a high dissolved oxygen value was recorded (7.9 mg/L) in Lower Zab tributary.

Age and growth of a population of Varicorhinus trutta (Heckel) from Tigris river at Salahuldin province have been investigated during the period from September 1999 to August 2000. A total of 156 fishes were collected from two stations at Tigris river using small meshed gill nets. The age data revealed that the species under investigation reached to a maximum age of seven years and approximately 46 cm long. The population of this species in Tigris river at the sites of study was dominated by 3 and 4 years classes. There were no marked differences in growth or longevity between the sexes. Determination of length-weight relationship revealed that the growth of both sexes in the species under investigation was allometric and the values of b

Surface water samples from different locations within Tigris River's boundaries in Baghdad city have been analyzed for drinking purposes. Correlation coefficients among different parameters were determined. An attempt has been made to develop linear regression equations to predict the concentration of water quality constituents having significant correlation coefficients with electrical conductivity (EC). This study aims to find five regression models produced and validated using electrical conductivity as a predictor to predict total hardness (TH), calcium (Ca), chloride (Cl), sulfate (SO4), and total dissolved solids (TDS). The five models showed good/excellent prediction ability of the parameters mentioned above, which is a very

Swabs from two hospitals at Baghdad city were collected from the period 28-October-2013 to 31-March-2014, to found out the prevalence and distribution of fungi. These isolates were collected from hospitals' environment and most of the items used for hospital work in order to detect the nosocomial pathogens persistent. All fungal isolates were identified depending on the morphological and microscopic examinations as well as biochemical tests. Out of 220 environmental samples, 146 fungal isolates was obtained, Aspergillus flavus was more frequency and occurrence 23.29% and 15.45% respectively, followed Aspergillus niger was 15.57% and 10.45% then Penecillium spp. was 13.27% and 8.64%. In Al -Yarmouk Teaching Hospital more places contaminat

     10 sites were selected for investigating zebra mussels in the Tigris River for the study that was conducted for the period from January to December 2020. The results of this investigation showed that zebra mussels were recorded in the Tigris at Taji on sites 7, 8, 9 and 10, while it was not found in the Tigris at Kut on sites 1, 2, 3, 4, 5 and 6. This is the first time that this species was ever recorded in the Tigris. It was found that the sites where zebra mussels appeared had a clear impact on the decrease in the total organic carbon %age and turbidity (NTU). High dissolved oxygen values were observed in the sites where zebra mussels were recorded, and the appearance of zebra mussels in these sites caused a clear decrease in

Seasonal variations of the species composition and abundance of Cladocera were studied in two stations at the end of the Tigris River and one station at the confluence of the Tigris with Euphrates area, at the beginning of the Shatt Al-Arab River in Al-Qurnah North of Basrah Province, from October 2015 to August 2016. Samples of zooplankton were collected by plankton net 100-µm. mesh size. The population density of Cladocera ranged between 1 Ind /m³ during summer and 211 Ind./m³ during winter at station 1 (Al-Jewaber Bridge). A total of 16 species of Cladocera belonging to 12 genera were recorded in the study. The average density of Cladocera ranged from 23.2 ind./m³ at Station 2 (Hamayon Bridge) to 53.7 Ind./m³

Age and growth of Varicorhinus damascinus (Val.) in Tigris river at Salahuldin province have been investigated. Monthly samples were taken during the period from September 1999 to August 2000, using small-meshed gill nets. The age data showed that there were six age groups and the dominant age groups were (III – IV) for both sexes. The results of the present study revealed that the increment in length of V. damascinus at the sites of study showed a tendency to decrease with the increase in age, after the third year of life in both sexes. The length-weight relationship of males and females were calculated and demonstrated in a straight line logarithmic formula, as follows: Log W = 1.5404 + 2.6885 log L for males r = 0.95 (P > 0.05) Log

F0od  and  feeding habits  of  Hetropnezt.s!fes ]ossili/}:. (Bloch)  have been  investigated.  Monthly samples (twice a  m()nth}  were   taken during  the period  from  March  2000  to February  20.Ql , using small -

meshed cast net. A total of l9J  ftsh were used to examine the stomach

contents.

The analysis   of  stomach contents of H  fo.s-silis in  the- area  of study  revealed   that  fish  were  fed  on  the  bottom, mid ·surface  and surface  &