Recently, it has been found that an invasive species named Charru mussel (Mytella strigata), native to the South and Central American coasts, is spreading quickly in the backwaters of Kerala. The proliferation of Charu mussel poses a serious threat to the endemic species diversity of brackish water habitats of Kerala coast.
- Charu mussels, first found in Florida in 1986, are presently found from Central Florida to the shores of Central Georgia.
- This invasive species is forcing out other mussel and clam species in the backwaters and threatening the livelihoods of fishermen engaged in molluscan fisheries.
- An invasive species is an organism that is not indigenous, or native, to a particular area and causes harm.
- The surveys conducted in Kerala has found presence of Charru mussel in many estuaries/backwaters of Kerala, which include Kadinamkulam, Paravur, Edava-Nadayara, , Kayamkulam, Vembanad, Chettuva and Ponnani etc. Ashtamudi Lake, a Ramsar site in Kollam district is the worst-hit due to Charu mussel.
- According to a paper published in the journal 'Aquatic Biology and Fisheries', Charu Mussel has seen a rapid spread in the year 2017 due to cyclone Ockhi.
- The Charru mussel may have reached the Indian shores attached to ship hulls or as larval forms in ballast water discharges. Ballast is the seawater that ships carry to improve stability.
- Known as 'Mytella Charruana', is native to the South and Central American coast.
- Their colour varies from black to brown, purple or dark green. They can survive in a range of salinity and temperature but cannot survive beyond 36 degree celcius.