The U.S. Coast Guard has released a draft policy letter on the implementation of new nonviable-organism testing protocols for ballast water management systems, as required by the passage of the Vessel Incidental Discharge Act (VIDA).
The “nonviable” method is based on a determination of whether aquatic organisms in ballast water can reproduce after treatment, and it is already used to satisfy IMO standards for BWMS performance worldwide. The unique U.S. Coast Guard standard – called “vital stain” – requires test labs to certify that a BWMS renders organisms incapable of visible movement after treatment (and therefore “dead”). Some critics of the Coast Guard standard maintained that non-moving was not necessarily equivalent to non-living; others have suggested that reproductive viability is a better measurement of an organism’s invasive potential.