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Head capsule deformities in C hironomus spp. ( D iptera: C hironomidae) as indicator of environmental stress in S ebeta R iver, E thiopia
Author(s) -
Beneberu Getachew,
Mengistou Seyoum
Publication year - 2015
Publication title -
african journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.499
H-Index - 54
eISSN - 1365-2028
pISSN - 0141-6707
DOI - 10.1111/aje.12175
Subject(s) - urbanization , chironomidae , industrialisation , geography , ecology , biology , larva , economics , market economy
Urbanization and industrialization have placed most of the aquatic environments in developing countries at great risk. The absence of reliable biological monitoring programmes further complicates the situation. In this study, an attempt was made to assess incidence of deformities among Chironomus spp. response to the level of environmental degradation. For this purpose, chironomid larvae were sampled from Sebeta River (November, 2012) using Surber sampler and/or D‐frame dip net. Moreover, physico‐chemical analysis of the water and sediment heavy metal analysis were carried out at three study sites. The results indicate that most physico‐chemical variables were higher at the downstream sites ( P < 0.05), together with high levels of Cr, Zn and Cu, which was attributed to untreated effluents that originated from garment and tannery industries. Several forms of deformities (mentum gap, notch, tooth missing and breakage) were encountered, and the majority occurred on mentum followed by pecten epipharynx. Taking 8% as a cut‐off value for normal deformities and the moderate rate of deformities detected (16.62% at Sb‐2), it is possible to conclude that the ecological state of Sebeta River is at critical condition. Therefore, corrective measures like designing of effective treatment plants and timely set environmental impact assessment must be in place prior to any developmental activity.