Better water quality in Kerala after the floods: study

KOZHIKODE: which have been heavily contaminated due to the dumping of various types of waste, were cleaned during the floods that affected the state in 2018. It had a positive effect on water bodies, according to a study by Kochi researchers. with headquarters ().

The devastating floods led to an increase in freshwater flow in the estuaries. Samples of the surface waters of the ecosystems were taken, namely. lower end of estuaries, intertidal waters of beaches, region of mud banks and coastal waters, of some districts of the state.

“We conducted the water quality assessment during August-September 2018 in some selected coastal marine ecosystems, namely. lower end of estuaries, intertidal waters of beaches, mud bank and coastal waters region of Malappuram, Thrissur, Ernakulam and Kollam, ”said D Prema, principal scientist, fisheries environment management division (FEMD), CMFRI.

Samples of surface waters were taken to analyze selected indicators of water quality using standard protocols and analytical methods.

The results revealed that, compared to the period before the flood, there was a higher nutrient content, especially dissolved inorganic nitrogen (DIN) in the Vembanad and Ashtamudi lakes. Most of the DIN was of the total ammoniacal nitrogen content. Total suspended solids (TSS) were higher in Ashtamudi but not in Lake Vembanad. In both lakes, the chlorophyll content was higher compared to the period before the flood.

Similar trends were observed for nutrients and chlorophyll in samples collected from intertidal waters. The mud bank region showed an increase in nutrients, chlorophyll and TSS. Regions near the coast off Kochi and outside also showed an increase in nutrients, chlorophyll and TSS.

Prema said the study clearly indicated that the ecology of the estuary and coastal waters is affected by floods that can affect fishery resources and community restrictions on these habitats. The researchers compared the findings with existing data on water quality.

“This should indicate that there would have been changes in the biodiversity of the systems. Such an increase in nutrients could have helped phytoplankton that are foods for organic life in water bodies, including fish, Prema added.