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WHAT THE NIO STUDY SAYS
* All the seasons, indicated a mesotrophic condition in the estuary and the assimilative capacity of the estuary is found to be in good to fairly good state
* During pre-monsoon... the prevailing marine conditions and other influencing environmental factors change the water quality making it slightly polluted
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WHAT IT SUGGESTS
Stringent regulations should be implemented to preserve and regulate the water quality for sustainable development in future
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PANAJI: The monsoon dominated Mandovi estuary in Goa has a ‘fairly good’ capacity to assimilate waste, with its capacity being the best in the post monsoon season, a study conducted by researchers at the National Institute of Oceanography has revealed.
The study tested the quality of water at several locations along the Mandovi estuary for parameters like dissolved oxygen, presence of phosphates, nitrates and turbidity to test the water’s ability to digest the waste that is thrown at it either naturally or through human intervention.
“Though there are a number of tourism related activities in the region, the overall water quality condition in the Mandovi estuary remains considerably good,” the final report of their study states.
“All the seasons, indicated a mesotrophic condition in the estuary and the assimilative capacity of the estuary is found to be in good to fairly good state,” the study reads.
The report has been conducted by the National Institute of Oceanography along with student researchers from the School of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu as well as one researcher from the Department of Biotechnology Engineering, International Islamic University Malaysia (IIUM), Kuala Lumpur.
“During post-monsoon...the water in the estuary is of acceptable quality. During pre-monsoon...the prevailing marine conditions and other influencing environmental factors change the water quality making it slightly polluted. The high land runoff during the SW monsoon contributes to large quantities of suspended matter; transports land derived and riverine organic material from the upstream region to the estuarine region. This changes the water quality of the estuarine water making it slightly polluted at the mouth during the SW monsoon season,” the researchers have said.
The researchers have classified the water in the Mandovi estuary as ‘mesotrophic’, or having a ‘moderate amount of dissolved nutrients’.
In mesotrophic water bodies, the water is moderately clear and organic matter is average as opposed to oligotrophic water bodies which sport a clear water or eutrophic water, which are characterized by algal blooms and high organic content.
A crucial parameter the researchers checked is the amount of dissolved oxygen in the water. The higher the dissolved oxygen indicates a higher assimilative capacity of the estuary water.
The study however warns that while “The overall assimilative capacity of the estuary is good and the estuarine water appears to be healthy... the slightly polluted water condition observed at selected stations in the Mandovi estuary could be a signal of gradually increasing anthropogenic pressure from various ongoing developmental and tourism activities on the aquatic ecosystem.”
