Ballast Water Management | connecting-the-dots

Ships need to have a certain level of immersion into the sea to be stable. When a ship discharges cargo, it rises up in the water and therefore, to keep a minimum level of immersion, ship staff take in sea water called ballast water inside tanks in the ship. And when the ship loads cargo, leading to more immersion, the ballast water is pumped out of the ship.
Until recently, there was no bar on taking in and pumping out of ballast water at ports, in the ocean, along the coast and so on.
Since ballast water carries invasive species into other countries that destroy ecosystems, global shipping has sought to regulate ballast water discharge.

The Ballast Water Management (BWM) Convention of the International Maritime Organization (IMO) came into force in 2017 to help prevent the spread of potentially harmful aquatic organisms and pathogens in ships’ ballast water.
From September 8, 2017, ships must manage their ballast water so that aquatic organisms and pathogens are removed or rendered harmless before the ballast water is released in a new location.
as of July 2, 97 countries have signed on to the BWM as contracting states.
India is not on the list of countries.

most serious about preventing ship ballast water damaging their marine ecosystems are Australia and New Zealand.
Australia is home to ecologically sensitive areas such as the Great Barrier Reef

Pulicat lake in Tamil Nadu, as in Ashtamudi lake in Kerala, charru mussel, Mytella Rigata has replaced almost all other species, he says.
Its survival rate and egg production is very high.
Though of marine origin, it can survive even in fresh water,
! In Bharat, nearly 30 invasive species coming from ship ballast water.