author(s)
Amardeep Kaur, Adnan Abubakr and Syed Shabih Hassan

abstract
The purpose of the study was to evaluate the trophic status of Nigeen Lake, through the interaction of nutrient concentration based on Carlson’s TSI. In order to determine the trophic status of Nigeen Lake, surface water samples from six different sites of the lake were collected from December 2015 to May 2016. Monthly as well as seasonal variation among different parameters was observed during the study period. Highest temperature was recorded during spring season along with higher values of depth, conductivity, ortho-phosphate, total phosphorous and chlorophyll-a during this season. However, dissolved oxygen, transparency and pH values were minimum during spring and maximum in winter season. The data analysis from Carlson’s TSI indicates that the average TSI(SD) value was in the range of 47.19 to 56.26, TSI(TP) ranged from 84.63 to 85.6 and TSI (Chl-a) was in the range of 58.24 to 61.37. The overall results of the study showed that the Carlson’s TSI (Total) of Nigeen Lake ranged from 65.7 to 67.7 indicating that the lake is in hyper-eutrophic condition. The myriad ways in which people use the lake along with the numerous pollutant-generating activities have stressed the lake ecosystem in diverse ways. The study suggests that managers and policy makers should take action to slow down or halt eutrophication by applying best management practices for the conservation of Nigeen Lake.