WRD seeks Rs 160 crore from Ennore port to remove invasive Charru Musse

CHENNAI: Concerning the spread of Charru Mussel (Mytella Strigata), locally called ‘Kakka Aazhi’, on the Kosasthalaiyar backwaters impacting fishermen, the Tamil Nadu Water Resources Department (WRD) has sought Kamarajar Port Limited Rs 160 crore to remove the invasive species.

Informing the southern bench of the National Green Tribunal (NGT) of the spread of invasive species along the stretch of the Kosasthalaiyar backwater, Buckingham Canal, and Pazhaverkadu mouth, the WRD submitted that the proliferation of Charru Mussels, microbes, and algae is not just harmful to the water bodies and marine ecosystem but also the endemic species in brackish water.

“The movement of ship hulls along the Indian shores has resulted in the rapid spread of the invasive Charru Mussel, native to the South and Central coast of America. The lack of ballast water regulation, for ship movement from the south and central coast of America, at the Kamarajar Port Limited in Ennore is the main reason for the spread of the Charru Mussels on the North Buckingham Canal, Kosasthalaiyar backwater and Pazhaverkadu Mouth,” the WRD told NGT in its report.

Earlier, the department prepared an estimate of Rs 8.5 crore to dredge the backwaters of the Kosasthalaiyar River up to 700 metres and sent a proposal to the Tamil Nadu Wetland Authority on the same.

In the meantime, the department found that the Charru Mussels have spread beyond Karukumaram - Kandachedi Paadu (fishing grounds) to Pazhaverkadu mouth for 16 kilometers.

“The dredging work needs to be extended till the Pazhaverkadu mouth for facilitation of tidal exchange to nourish the growth of crustacean species such as crab, prawns, mullets and others,” the report highlighted.

Alleging that the Ennore port authorities failed to take precautions to mitigate the spread of Charru Mussels, the WRD requested the NGT to invoke the ‘polluters pays’ principle and sought Rs 160 crore from the Kamarajar Port Limited as its contribution.

In December 2022, fishermen from Kattupakkam and environmentalists from the Save Ennore Creek Campaign raised concerns regarding the unchecked invasion of Ennore and Pulicat wetlands by Charru Mussel. They said the invasive species spread like a carpet at the bottom of the river and prevent prawns from grazing or burying themselves in the sediment. The alien species also wipe out the locally prevalent yellow clams (manja matti) and green mussels (pachai aazhi).