Assessing the risks of invasions of aquatic invertebrates in the Shatt Al-Arab River

Abstract

The Shatt Al-Arab is an important invasion gateway in West Asia. Protocols of the ALARM project were used for estimation of risk assessment of aquatic invasions. There are five global alien species with high invasiveness which are widespread among the region ( Eriocheir sinensis, Macrobrachium nipponense, Palaemon elegans, Balanus amphitrite , and Potamorpyrgus antipodarum ). Identification and analysis of invasion pathways within the region show a predominantly secondary natural spread of alien species and also the importance of navigation and canals for recent expansion of alien species. Five assessment units (Harir region, Abu Al-Khaseeb, Al-Sindibad, Qurna, and Garmat Ali) have extremely high and one (Shatt Al-Basrah) has high biological contamination and risk of biological pollution. Alien species increase similarity of macrozoonbenthic communities (biotic homogenization). Among key drivers of biological invasions in this region, a special place is occupied by geopolitical conflict and competition for natural resources which form a unique man-made hydrological regime in the Mesopotamian rivers.