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The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas.

The current study included two sites in the middle part of Shatt Al-Arab-Southern Iraq (Al-Ashar and Al-Deir sites), the concentrations of trace elements which represented by Uranium, Arsenic, Beryllium and Vanadium were measured in water and sediments of four seasons from autumn 2018 to summer 2019. The concentrations of trace elements showed variations at the level of significance in the water and sediments, Uranium recorded its highest concentration in the study water (6.1U / l) at the spring of Al-Deir site. While its highest concentrations in sediments reached (2.4 mg / kg) at Al-Ashar site, moreover the highest concentration of Arsenic in water was (4.2U / l) at autumn of Al-Deir site and (6.1 mg/kg) for sediments at Al-Ashar site, as well as the concentration of Beryllium was below the detection limit (BDL) in water, while its highest concentration in sediments was recorded (1.1 mg/kg) as well as the highest concentration of Vanadium was (8.4U/l) in water and (87 mg/kg) in sediments.

The current study included two sites in the middle part of Shatt Al-Arab-Southern Iraq (Al-Ashar and Al-Deir sites), the concentrations of trace elements which represented by Uranium, Arsenic, Beryllium and Vanadium were measured in water and sediments of four seasons from autumn 2018 to summer 2019 . The concentrations of trace elements showed variations at the level of significance in the water and sediments, Uranium recorded its highest concentration in the study water (6.1 µg/l) at the spring of Al-Deir site. While its highest concentrations in sediments reached (2.4 µg/g) at Al-Ashar site, moreover the highest concentration of Arsenic in water was (4.2 µg/l) at autumn of Al-Deir site and (6.1 µg/g) for sediments at Al-Ashar site ,as well as the concentration of Beryllium was below the detection limit (BDL) in water , while its highest concentration in sediments was recorded (1.1µg/g) as well as the highest concentration of Vanadium was (8.4 µg / l) in water and (87µg/g) in sediments.

No abstract