Effect of the biotic and abiotic factors on the abundant species of macrobenthic invertebrates in northern Khors of Lake Nasser | ||||
| Egyptian Journal of Aquatic Biology and Fisheries | ||||
| Article 60, Volume 25, Issue 5, September and October 2021, Page 1033-1061 PDF (1.32 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejabf.2021.209129 | ||||
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| Author | ||||
| Isaac A. Iskaros et al. | ||||
| Abstract | ||||
| Major macrobenthic invertebrates’ groups along with the surrounding environmental conditions of four important khors located in the northern sector of Lake Nasser were seasonally analyzed during 2015. For better understanding the community structure and the diversity of the main functional groups of organisms, the following parameters were considered: temperature, transparency, electrical conductivity, hydrogen ion concentration, dissolved oxygen, nitrite, nitrate, orthophosphate and chlorophyll-a. Besides, the type of sediments and their contents (organic matter and calcium carbonate) and heavy metals (iron, manganese, zinc, and copper) were also determined. A number of 27 taxa, belonging to 16 families of macrobenthic invertebrates, were encountered in the northern khors of Lake Nasser. Specimens contained 10 chironomid larvae, 3 odonate nymphs, 5 annelids, 5 mollusks, 1 decapod, and 1 adult corixid. In addition, 2 unknown species belonging to ephemeropteran nymphs and trichopteran larvae were identified. The combined contribution of aquatic insects, molluscs, and oligochaetes constituted the abundant groups of khors’ macrobenthic invertebrates throughout the study period. The highest density of macrobenthic invertebrates was recorded at the littoral sites of Khor El-Ramla (ann. aver. 3262 ind./m2 with 15.5 GFW/m2) and Khor Kalabsha (ann. Aver. 2983 ind./m2 with 19.8 GFW/m2) accompanied with some patches of submerged macrophytes. The declined density values were observed at Khor Rahma (ann. aver. 825 ind./m2 with 9.8 GFW/m2), where most of the aquatic plants disappeared. Shannon (H) diversities of those communities were measured. The results of the analysis variance on SPSS and Pearson correlation coefficient showed that water temperature, transparency, electrical conductivity, hydrogen ion concentration, dissolved oxygen, Chlorophyll-a, nitrite, nitrates orthophosphate, organic matter and calcium carbonate are the most influential parameters on different groups of macrobenthic invertebrates at varying degrees. The data obtained in this investigation would be crucial to understanding macrobenthic invertebrates’ regulation and would hence contribute to the knowledge regarding the limnology of Lake Nasser, particularly after the establishment of Renaissance Dam in Ethiopia. | ||||
| Keywords | ||||
| Lake Nasser; The northern Khors; Water quality; Macrobenthic invertebrates; Species composition | ||||
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