Pollution Potential Assessment of Nymphaea alba in Nigeen Basin of Dal Lake, Kashmir (J&K), India

Abstract

The present study was conducted to investigate the biochemical attributes of Nymphaea alba (also known as the European White Water lily or Nenuphar), an annual or perennial aquatic flowering plant at three study sites viz., site I (Nagoo Mohalla, near residential area); site II (Ashaibagh-adjacent to floating gardens) and site III (Marzibagh-Nigeen boat club) in Nigeen Basin of Dal Lake, Kashmir. The sampling was done on monthly basis and the entire study period was divided into two phases i.e., the active growth phase (summer-June, July and August) and the senescence phase (early winter-September, October and November). Comparative biochemical assessment of three sites revealed chlorophyll ‘a’ ranging from 2.371 µg mL^-1 (site-III) to 3.266 µg mL^-1 (site-I); chlorophyll ‘b’- 0.382 µg mL^-1 (site-III) to 0.588 µg mL^-1 (site-I); total chlorophyll, 3.184 µg mL^-1 (site-III) to 4.262 µg mL^-1 (site-I), while as carotenoids varied between 0.438 µg mL^-1 (site-III) to 1.083 µg mL^-1 (site-I). Proteins and amino acids elevated from a range of 0.328 mg mL^-1(site-III) to 0.578 mg mL^-1 (site-I) and 2.884 mg mL^-1 (site-III) to 3.823 mg mL^-1 (site-I) respectively. The starch and carbohydrate content obtained a concentration range of 8.486 mg mL^-1 (site-III) to 10.302 mg mL^-1 (site-I) and 10.009 mg mL^-1 (site III) to 12.769 mg mL^-1 (site-I) respectively. The results revealed that the biosynthesis of various biomolecules accelerated during the active growth phase at Site-I (June) due to optimum physico-chemical parameters of water such as temperature (27°C); pH (8.9); free carbon dioxide (20.0 mg L^-1); and high concentrations of nitrate-nitrogen (427.3 µg L^-1) and total phosphorous (226.8 µg L^-1) while as, low range of biomolecules was observed at site-III in the senescence phase (November) due to decrease in various physico-chemical parameters of water (temperature, 5.0°C; pH,7.2; free carbon dioxide, 16.4 mg L^-1; nitrate-nitrogen, 201.7 µg L^-1; and total phosphorous, 203.5 µg L^-1) from summer to early winter season. The study concludes that high nutrient load owing to various anthropogenic activities during active growth phase enhanced the growth of Nymphaea alba at site I as it increased biosynthesis of its various biomolecules in comparison to site III (control site) which is attributed to various clean-up activities taken up around this site. The study, thus recommends urgent scientific measures including proper management, conservation and restoration of lake. Furthermore, human habitation around the lake catchment demands sustainable protection measures to limit further degradation of the lake.