Effect of Dredging on the Macrozoobenthos of Hazratbal Basin in the Dal Lake Srinagar Kashmir, India

In order to assess the effect of dredging on macrozoobenthos community, study was carried out in the Hazratbal Basin of Dal Lake from August 2010 to January 2011. The results showed strongly significant differences (P<0.05) between control site and the site which was sampled after dredging operation. The significant differences were also found between pre-dredging and post-dredging (P = 0.004), while as, there were no significant differences between control site and pre-dredged site (P = 0.191). Altogether 6 taxa were observed at post dredged site in comparison to the pre-dredged (9 taxa) and the control site (10 taxa). At control site, molluscans were found to be the dominant group (1255 ind/m) followed by annelida (1110 ind/m) and diptera (330 ind/m), There were six taxa were shared both sites (control, impact sites) and one taxa Erpobdella octoculata of annelida was only restricted to control site. The abundance of most taxa were significantly higher at control and pre-dredged site. Three species (Lymnea stagnalis, Radix auricularia and Radix ovata) were completely eliminated after dredging operation. A cluster analysis showed that macrozoobenthic communities revaealed 90% similarity levels between control site and pre-dredged site. After dredging similarity level was greatly declined and was recovered 76% after six months of dredging.