Mondal Debjit Kumar, Kaviraj Anilava
Department of Zoology, University of Kalyani, Kalyani, West Bengal, 741235, India.
Ecotoxicology. 2008 Apr;17(3):207-11. doi: 10.1007/s10646-007-0185-6. Epub 2007 Dec 22.
Severe deterioration of water quality occurs during jute retting in ponds, canals, floodplain lakes, and other inland water bodies in the rural areas of West Bengal in India. Attempts were made to evaluate changes in the physicochemical parameters of water caused by jute retting, and their impact on the survival of two species of freshwater fish (Labeo rohita and Hypophthalmicthys molitrix) and two species of freshwater invertebrate (Daphnia magna, a Cladocera, and Branchiura sowerbyi, an Oligochaeta). Results showed that jute retting in a pond for 30 days resulted in a sharp increase in the BOD (>1,000 times) and COD (>25 times) of the water, along with a sharp decrease in dissolved oxygen (DO). Free CO(2), total ammonia, and nitrate nitrogen also increased (three to five times) in water as a result of jute retting. Ninety-six-hour static bioassays performed in the laboratory with different dilutions of jute-retting water (JRW) revealed that D. magna and B. sowerbyi were not susceptible to even the raw JRW whereas fingerlings of both species of fish were highly susceptible, L. rohita being more sensitive (96 h LC(50) 37.55% JRW) than H. molitrix (96 h LC(50) 57.54% JRW). Mortality of fish was significantly correlated with the percentage of JRW.
在印度西孟加拉邦农村地区的池塘、运河、洪泛区湖泊及其他内陆水体中进行黄麻浸沤时，水质会严重恶化。人们试图评估黄麻浸沤导致的水体理化参数变化，以及这些变化对两种淡水鱼（印度鲤和草鱼）和两种淡水无脊椎动物（大型溞，一种枝角类动物，以及苏氏尾鳃蚓，一种寡毛纲动物）生存的影响。结果表明，在池塘中进行30天的黄麻浸沤会导致水体的生化需氧量（BOD）急剧增加（超过1000倍）和化学需氧量（COD）急剧增加（超过25倍），同时溶解氧（DO）急剧减少。由于黄麻浸沤，水中的游离二氧化碳、总氨和硝酸盐氮也有所增加（三到五倍）。在实验室中用不同稀释度的黄麻浸沤水（JRW）进行的96小时静态生物测定表明，大型溞和苏氏尾鳃蚓即使对未稀释的JRW也不敏感，而两种鱼类的鱼苗则高度敏感，印度鲤比草鱼更敏感（96小时半数致死浓度（LC50）为37.55%的JRW）（草鱼的96小时LC50为57.54%的JRW）。鱼类的死亡率与JRW的百分比显著相关。
