Arimoro Francis O, Ikomi Robert B, Iwegbue Chukwujindu M A
Department of Zoology, Delta State University, P.M.B. 1, Abraka, Nigeria.
Pak J Biol Sci. 2007 Feb 1;10(3):446-53. doi: 10.3923/pjbs.2007.446.453.
A study of the aquatic oligochaetes of an organically polluted segment of an urban stream in Southern Nigeria was carried out to assess the ecological impact of abattoir effluent. Three stations 1, 2 and 3 were selected from upstream of the site receiving abattoir effluent, the impacted site and its down stream, respectively. Among the water quality variables, conductivity, dissolved oxygen, BODs, Nitrate-nitrogen, Phosphate-phosphorus and water hardness were significantly different (p < 0.05) among the stations. Orthogonal comparison using Duncan's multiple range test showed that station 2 (the impacted site) was the cause of the difference. A total of 14 species of oligochaetes were identified with 13 (92.8%) occurring in the impacted station. Tubifex, Dero limnosa and Nais communis were the dominant taxa, less frequent were Stylaria, Aelosoma and Lumbriculus variegatus (Muller). Pistina and Chaetogaster species were sporadically present. The density of the different taxonomic groups differed among the stations with the impacted station accounting for the greatest abundance and diversity of the organisms. The organic wastes from the abattoir not only altered the water chemistry but also stimulated the abundance of oligochaete worms.
对尼日利亚南部一条城市溪流受有机污染河段的水生寡毛纲动物进行了一项研究，以评估屠宰场废水的生态影响。分别从接收屠宰场废水的地点上游、受影响地点及其下游选取了1号、2号和3号三个站点。在水质变量中，各站点之间的电导率、溶解氧、生化需氧量、硝酸盐氮、磷酸盐磷和水硬度存在显著差异（p < 0.05）。使用邓肯多重极差检验的正交比较表明，2号站点（受影响地点）是造成差异的原因。共鉴定出14种寡毛纲动物，其中13种（92.8%）出现在受影响站点。颤蚓、Limnodrilus hoffmeisteri和普通仙女虫是优势类群，苏氏尾鳃蚓、颤蚓属和正颤蚓则较少出现。 Pistina属和毛腹虫属物种偶尔出现。不同分类组的密度在各站点之间存在差异，受影响站点的生物丰度和多样性最高。屠宰场的有机废物不仅改变了水化学性质，还促进了寡毛纲蠕虫的大量繁殖。
