Seasonal variations in levels of heavy metals in leaves of Ceratophyllum demersum from Al-Garaf canal at Thi-qar province, Iraq

The present investigation represents a part of a comprehensive ecoioglcal work aiming to evaluate the environmental status of Al- Garaf canal at Thi-Qar Province.It is, specifically , taking in consideration determining the seasonal variations in levels of some heavy metals (i.e. Ni,Ca, and Cu Zn) in leaves of submerged aquatic plant (Ceratophyllum demersum) .The study was performed on seasonal basis. Samples were collected from a iocation supply Basrah Thi – Qar Shatra and Garaf water purification units withcrude low salinity fresh water . The specified location receives effluents from the surrounding uran areas, enriched with some industrial wastes domestic sewage and maintains fishing activities . It represents a mixing zone of water masses .The study deduced that accumulation varies seasonally within the plant leaves ,but Ni(85.71ug/gD.W)and Zn (48.90ug/gD.W)showed the highest levels and the minimal excusive value exhibited by Cd (1.81ug/gD.W) Recovered elements can be arranged as follows :Ni Zn Cu Cd.