Question

Common indicator organism of water pollution is

• A. Eichhornia crassipes
• B. Escherichia coli
• C. Entamoeba histolytica
• D. Lemna pancicostata

Answer 1

Answer: (D)

Lemna pancicostata

Answer 2

Physico-chemical indicators: These are conventional parameters commonly associated with water quality assessment. They encompass measurements such as dissolved oxygen levels, pH, temperature, salinity, and the concentration of nutrients like nitrogen and phosphorus. Physico-chemical indicators also include assessments of pollutants like insecticides, herbicides, and heavy metals. Biological indicators: Biological indicators offer a direct evaluation of the overall health of aquatic ecosystems by examining the condition of the resident plants and animals. In freshwater environments, these indicators involve assessing factors like the diversity of macroinvertebrates or fish, the growth of benthic algae, and the oxygen demand in benthic communities. Flow indicators: In freshwater systems, changes in water flow often play a pivotal role in the degradation of aquatic ecosystem health. For instance, the Murray-Darling system is a notable example of this phenomenon. Evaluating alterations in natural flow patterns caused by human activities is crucial. These changes can encompass modifications in peak flows, base flows, the absence of flow during certain periods, and alterations in seasonal flow patterns.