Assessment of water quality and ecosystem health of a canal system during the lockdown period

The impacts of the lockdown period on water quality and ecosystem health in an artificial canal water system were investigated from the rapidly growing Kozhikode City in India. The ecosystem health is measured in terms of water quality indicators such as pH, electrical conductivity (EC), dissolved oxygen (DO), biological oxygen demand (BOD) and Escherichia coli (E. coli) during the pre-lockdown and lockdown period. The study reveals the massive improvement of the ecosystem health of the canal in terms of DO, BOD, and E. coli during the lockdown period. DO values were improved from anoxic (0 mg/L) to oxic (> 5 mg/L), BOD reduced from 31 to 0.7 mg/L as well as E. coli at major urban stretches were 800 MPN/100 mL, which was observed to be absent during the lockdown period. Urban stretches of the canal implicitly proved that the lockdown period was not sufficient to recover the natural ecosystem condition of the canal system. Principal component analysis revealed that the ecosystem health of the canal majorly governs two factors, such as the weathering process and anthropogenic waste sources. The study advocates the policy makers that temporary pollution source control in a timely interval may heal the environment and is useful to the regulatory bodies for suggesting the pollution source control mechanism.