Alappuzha: In an interesting development, recent studies have shown that Kuttanad and Vembanad Lake are rich in carbon sinks. According to researchers, both these areas have rich 'blue carbon' deposits due to the sedimentation of alluvial soil and are essential in mitigating climate change. 

"Carbon deposition in Kuttanad and Vembanad Lake is mainly due to the sedimentation of alluvial soil or silt. There is a blue carbon deposit at a depth of 80 metres here, which needs to be scientifically studied and utilised prudently by implementing sound plans," said Dr K.G Padmakumar, Director of the International Aquaculture Centre and an expert in this field. 

Kuttanad is rich in alluvium deposits due to the Pampa, Achankovil, Manimala, Meenachil and Muvattupuzha rivers. The paddy cultivation here depends upon the alluvium soil deposits.

Furthermore, these paddy fields also serve as composting sites. The water that runs through these fields aids in the accumulation of alluvium deposits. It is estimated that around 1-20 tonnes of alluvium deposit can be found in one hectare of land. However, the banks of many streams in paddy cultivation areas have been reinforced with black stone walls, which impede the natural water flow.

Carbon sink
A carbon sink accumulates more carbon from the atmosphere than it releases. It stores this carbon for an indefinite period of time, thereby reducing the amount of carbon dioxide in the atmosphere. The forests, soil and water bodies are capable of absorbing carbon in this manner. 

Blue carbon
This refers to the carbon that is absorbed from the atmosphere and stored in troves like forests, oceans or soil. ‘Blue’ refers to the watery nature of this compound. This is usually found in mangroves, salt marshes, etc.