The Biobrio 13(1 & 2), 2026

Limnological assessment and trophic status evaluation of Latratu Dam, Ranchi, Jharkhand, India

Ravi Rahul Singh, Madhumanti & Prasanjit Mukherjee

ABSTRACT:

Freshwater ecosystems are crucial for ecological balance and human use but are increasingly affected by nutrient enrichment. This study evaluated the limnological characteristics and trophic status of Latratu Dam, Jharkhand, through seasonal analysis of physico-chemical, nutrient, and biological parameters across pre-monsoon, monsoon, and post-monsoon periods. Results showed clear seasonal variation, with reduced transparency, lower dissolved oxygen, and higher biological oxygen demand during the monsoon. Nutrient levels (nitrate, phosphate, and ammonia) increased significantly due to runoff, leading to higher chlorophyll-a concentration and phytoplankton density. The phytoplankton community was dominated by Cyanophyceae, indicating nutrient enrichment. The mean Carlson's Trophic State Index value (54.8) classified the reservoir as mesotrophic with signs of eutrophic progression. The study highlights the need for regular monitoring and nutrient management to prevent further ecological deterioration and ensure long-term sustainability.

Keywords:    

Limnology, trophic status, eutrophication, reservoir ecology, phytoplankton, nutrient dynamics

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