Diagnostic study of some types of algae present in the Tigris River passing through the city of Dhuluiya, Salah al-Din

Abstract

The current study was conducted on the course of the Tigris River in the city of Dhuluiya within Salah Al-Din Governorate in 5 stations, the first of which is located in Al-Nahrain district of Al-Dhuluiya district, which is located in the north of the city, and the last is located near the confluence of the Tigris and Al-Azim rivers in the village of Bishkan during the study period from September 2020 to the month of February 2021. Monthly water samples were collected from each station, and many physical and chemical tests were conducted for these samples, including water temperature, pH, turbidity, electrical conductivity, dissolved oxygen, biological oxygen, phosphate, nitrate, silica, as well as measuring The total number of phytoplankton and the diagnosis of algae present in the stations The results showed that the water temperature ranged between (11.5 - 27.3) degrees Celsius. As for the turbidity, it ranged between (3.25-146) N.T.U. The conductivity values ranged between (145-651) microsiemens/cm, and the pH values ranged between (7.4-7.95) and it was noted that the dissolved oxygen values ranged between (7.4-12.5) mg/L, and depending on BOD values, the water was Medium cleanliness, its levels ranged between (0.1-2.9) mg/l, as for plant nutrients, the silica values ranged between (0.02-4.2) mg/l. As for nitrates, their values ranged between (0.359-1.26) micrograms/liter and phosphate values ranged between (0.02-3.6) micrograms/liter. In the studied stations, 97 species of algae were diagnosed, and diatoms constituted the overwhelming majority of them, accounting for 72.16%. The most prominent genera of diatoms are Fragilaria, Synedra, Navicula, Nitzschia, Cymbella, Gomphonema, Surirella. Green algae came in second place with 17.52% of its genera: Chlorella, Pediastrum, Scenedesmus Spirogyra, Closterium, then blue-green algae with a percentage of 8.24%. Its genera: Lyngbya, Merismopedia, Oscillatoria, Spirulina, Tolypothrix . It was followed by Euglenophyta algae with a percentage of 1.03%, including the genus Euglena, and also the Pyrrophyta with a percentage of 1.03, including the genus Peridinium.