The Zarqa River has long served as a critical source of surface water in Jordan, originating from a spring in Amman and sustained by numerous large springs and seasonal floods as it flows toward the lower Jordan River. However, rapid urban expansion, industrial activities, and the continuous discharge of treated and untreated wastewater have severely degraded its ecological integrity. This study utilizes biological indicators, specifically macroinvertebrates and aquatic plant assemblages, to assess the river’s condition and provide a clearer, evidence-based picture of long-term water quality. Pollution-tolerant species such as Tubificinae, Physa acuta, and Chironomus (red larvae) were found in high numbers in heavily polluted sections of the river, while moderately polluted zones still support species like Baetis monnerati, blackflies (Simuliidae), and Hirudinea (leeches). In contrast, pollution-sensitive organisms such as Melanopsis gastropods and Trichoptera caddisflies were only observed in relatively clean areas, but notably, Theodoxus gastropods were entirely absent. Similarly, plant communities reflected pollution levels: Herbaceous plants like Eruca, Rumex, and Amaranthus thrive in degraded areas. Species such as Phragmites, Tamarix, Eucalyptus, Nicotiana, Nerium, and Cardaria tolerate a wide range of water qualities, from clean to polluted. However, their presence alone doesn’t reliably indicate water quality without supporting macroinvertebrate data. Spergularia cf. diandra, associated with Asteriscus and Pteranthus plant assemblage, indicates saline and alkaline conditions. Plants indicate salinity levels, but macroinvertebrates provide a better measure of water quality, distinguishing clean from polluted conditions more reliably. This assessment shows that aquatic plants and animals are effective, low-cost indicators for monitoring river health and are especially important in water-scarce Jordan. Alongside scientific monitoring, stronger enforcement of environmental laws is urgently needed to prevent pollution, protect public health, and ensure the Zarqa River’s long-term sustainability.Keywords: bioindicators, aquatic ecosystems, macroinvertebrates, water quality, pollution, environmental assessment, Zarqa River, Jordan
The Zarqa River has long served as a critical source of surface water in Jordan, originating from a spring in Amman and sustained by numerous large springs and seasonal floods as it flows toward the lower Jordan River. However, rapid urban expansion, industrial activities, and the continuous discharge of treated and untreated wastewater have severely degraded its ecological integrity. This study utilizes biological indicators, specifically macroinvertebrates and aquatic plant assemblages, to assess the river’s condition and provide a clearer, evidence-based picture of long-term water quality. Pollution-tolerant species such as Tubificinae, Physa acuta, and Chironomus (red larvae) were found in high numbers in heavily polluted sections of the river, while moderately polluted zones still support species like Baetis monnerati, blackflies (Simuliidae), and Hirudinea (leeches). In contrast, pollution-sensitive organisms such as Melanopsis gastropods and Trichoptera caddisflies were only observed in relatively clean areas, but notably, Theodoxus gastropods were entirely absent. Similarly, plant communities reflected pollution levels: Herbaceous plants like Eruca, Rumex, and Amaranthus thrive in degraded areas. Species such as Phragmites, Tamarix, Eucalyptus, Nicotiana, Nerium, and Cardaria tolerate a wide range of water qualities, from clean to polluted. However, their presence alone doesn’t reliably indicate water quality without supporting macroinvertebrate data. Spergularia cf. diandra, associated with Asteriscus and Pteranthus plant assemblage, indicates saline and alkaline conditions. Plants indicate salinity levels, but macroinvertebrates provide a better measure of water quality, distinguishing clean from polluted conditions more reliably. This assessment shows that aquatic plants and animals are effective, low-cost indicators for monitoring river health and are especially important in water-scarce Jordan. Alongside scientific monitoring, stronger enforcement of environmental laws is urgently needed to prevent pollution, protect public health, and ensure the Zarqa River’s long-term sustainability.
bioindicators, aquatic ecosystems, macroinvertebrates, water quality, pollution, environmental assessment, Zarqa River, Jordan