• Charru mussel is spreading quickly in the backwaters of Kerala, elbowing out other mussel and clam species and threatening the livelihoods of fishermen engaged in molluscan fisheries.
• The rapid spread of the Charru mussel may have been triggered by Cyclone Ockhi which struck the region in 2017.

What is Charru mussel?

• Charru mussel (Mytella strigata) is an invasive mussel native to the South and Central American coasts.
• Externally, the Charru mussel resembles the green and brown mussels (kallummekka in Malayalam), but is much smaller in size.
• Its colour varies from black to brown, purple or dark green.
• The short-necked clam fisheries in the lake had obtained an eco label from the Marine Stewardship Council and about 3,000 people are dependent on fisheries here.
• In such a scenario, the fast-breeding Charru mussel could be seen as a ‘pest’.