Invasive Caribbean false mussel species all but wipes out Kerala’s indigenous clams, oysters
The Caribbean false mussel has devastated native clams and oysters in Kerala, according to a report by the Platform on Biodiversity and Ecosystem Services.
New Delhi The Caribbean false mussel has wiped out almost all native clams and oysters of Kerala which are important for local fisheries, an intergovernmental panel report on biodiversity has said.
The Caribbean false mussel (Mytilopsis sallei) originally from the Atlantic and Pacific coast of South and Central America has spread widely in the state. Interestingly, it has also overwhelmed the American brackish water mussel, Mytella strigata, another invasive species which once threatened to take over the state’s waterways.
Researchers say the Caribbean false mussel may have travelled to India via ships, later spreading to estuaries through smaller fishing vessels that travel frequently between coastal oceanic waters and the fishing harbours of Kerala, the report on invasive species has said.
It has also said in its case study on India that it is possible that tropical Cylone Ockhi, which struck the Kerala coast in 2017, may have triggered the spread of the “Varathan Kakka” (alien mollusc in Malayalam) across the state by carrying it into new waters.
There are several other such case studies of invasive species that have played a key role in 60% of global plant and animal extinctions recorded by the report by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) released on Monday.
The report, which was approved by 143 IPBES member countries in Bonn, Germany, is an assessment report on invasive alien species and their control. It found that the global economic cost of invasive alien species exceeded $423 billion annually in 2019, with costs having at least quadrupled every decade since 1970.
In 2019, the IPBES Global Assessment Report found that invasive alien species are one of the five most important direct drivers of biodiversity loss – alongside changes in land and sea use, direct exploitation of species, the climate crisis, and pollution.
More than 37,000 alien species have been introduced by many human activities to regions and biomes around the world. “This conservative estimate is now rising at unprecedented rates. More than 3,500 of these are harmful invasive alien species – seriously threatening nature, nature’s contributions to people and good quality of life,” the report said.Some alien species had been intentionally introduced for their benefits.
But nearly 80% of the documented impact of invasive alien species on nature is negative, the summary for policy makers states.
Reduction in food supply is by far the most frequently reported impact across all taxa and regions.
Among examples, the SPM states that in northwestern Europe, Picea sitchensis (Sitka spruce) severely alters habitats such as coastal heathlands and mires, which are important habitats for threatened and endangered plants, birds and other species; Carcinus maenas (European shore crab) has had an impact on commercial shellfish beds in New England and Canada; Asterias amurensis (northern Pacific seastar) and Ciona intestinalis (sea vase) have negatively affected mariculture and fisheries along the Korean coast, and Mytilopsis sallei (Caribbean false mussel) has displaced native clams and oysters that are locally important fishery resources in India.
Further, IPBES said in a statement that invasive species also impact life through health impacts, including diseases such as malaria, Zika and West Nile Fever, spread by invasive alien mosquito species such as Aedes albopictus and Aedes aegypti.
“Invasive alien species have been a major factor in 60% and the only driver in 16% of global animal and plant extinctions that we have recorded, and at least 218 invasive alien species have been responsible for more than 1,200 local extinctions. In fact, 85% of the impacts of biological invasions on native species are negative,” said Anibal Pauchard, co-chair of the assessment in a statement.
Get Updates on India News, Farmers Protest Live alongwith the Latest News and Top Headlines from India and around the the world.