RESUMO
Annual survey of Jalmahal, Amer, Nevta and Ramgarh lakes, has been conducted for one calendar year, to determine physico- chemical characteristics of water and the levels of zinc (heavy metal) and endosulfan (an organochlorine pesticide). These lakes are situated on the outskirts of Jaipur city. Changes in pollutants correlated well with the physico-chemical characteristics of water bodies. Results reveal that the levels of endosulfan and zinc are highest in Jalmahal lake (1.324 and 0.197 mg l-1 respectively) and lowest in Ramgarh lake (0.020 and 0.120 mg l-1 respectively). Anthropogenic sources and cultivation in the dried up area of these lakes seem to contribute largely to pollution.
RESUMO
The present investigation was undertaken to assess the effects of sublethal concentrations of zinc (0.1 and 0.2 mgl(-1)) on the nutritional value of fish Channa punctatus after exposure for 135 days. The parameters studied were, levels of total proteins, glycogen, total lipids, cholesterol and vitamins (A and D) in the muscle. Total proteins, glycogen, total lipids and vitamin D show highly significant decline from day 90 to 135, while cholesterol and vitamin A, show no significant changes upto 105 days. This study signifies a drastic reduction in the nutritive value of fish, which is compounded by the fact that under natural conditions fish are exposed to these levels of zinc for prolonged periods.