THIRUVANANTHAPURAM: Kerala’s beaches have the least polluted waters in the country. Among the 12 coastal states/UTs in India, Kerala tops in Coastal Water Quality Index (CWQI), shows the “EnviStats India 2024: Environment Accounts” released by the Union government.
As per the data released on Monday, Kerala’s scores and rankings in 2023-24 improved from the previous year. The report had CWQI scores for three locations in the coastal sea and Kerala was ranked “Good” in all. For the location “At shore (less than 1km)” Kerala’s score was 74, followed by Karnataka (65), and Guajarat (60).
The state’s score for “At nearshore (2 km)” was 75, followed by Karnataka (65), and Gujarat (62). With 79 points, Kerala was also top in the “At offshore (5km)” location, and was followed by Karnataka (73), and Tamil Nadu and Goa, both 67.
“The report indicates our coastal waters are significantly better than those along the rest of the Indian coast. The improvement in water quality is likely due to the increased freshwater input during the monsoon season, which dilutes unwanted substances.
This positive change reflects a transition from an unhealthy to a healthy coastal ecosystem,” opined Dr Resmi T R, head in-charge of Ecology and Environment Research Group (EERG) of the Centre for Water Resources Development and Management (CWRDM).
The CWQI grading was: Very Poor (0-20), Poor (21-40), Moderate (41-60), Good (61-80) and Very Good (81-100). In 2022-23, Kerala’s scores and ranking in the three locations were 68 (Good), 56 (Moderate) and 67 (Good), respectively.
‘Kerala consistently scored high in the assessed years’
The parameters used for the assessment included physical (temperature, salinity, pH, etc), chemical (dissolved nutrients, total alkalinity, etc), biological (phytoplankton, zooplankton, etc), microbiological (total viable counts of E coli, Streptococcus faecalis, etc), and pollutants such as trace metals and petroleum hydrocarbons.
Kerala has consistently scored high in the assessed years starting from 2020-21, said Dr Magesh N S, scientist with the EERG. However, during 2020-21, the coastal water quality fell below 60, categorising it as ‘Moderate.’ In 2021-22, although Kerala’s CWQI remained in the moderate range, all values were below 50. From 2022-23, there was a steady improvement, with the CWQI reaching 79 for offshore waters in 2023-24. “There is a high chance for the state to get ranked ‘Very Good’ in the coming years,” Magesh said.
As per the report, 275.33 km of the state’s coast faced erosion during the 1990-2018 period. It was 46.4% of the total coast length of 592.96km. As much as 134.99 km (22.8%) of the coast faced accretion (growth) and 182.64 km (30.8%) remained stable.
“Shorelines constantly morph through erosion and accretion. South Kerala witnesses more accretion during monsoon and North Kerala at other times,” said State Hydrographic Survey wing head Gerosh Kumar V.