Why MPN?

There is no scientific dispute that destroying an organism’s ability to reproduce is an effective means of preventing and controlling aquatic invasive species. Here are six reasons why the USCG needs to accept the MPN method as an equivalent alternative to the vital stain method (promoted by the USCG) for determining the number of living organisms in the 10 – 50 μm size class.

6 Reasons the USCG Needs to Accept the MPN Method

Click on a link below for further information. You can also download a document with all six reasons [pdf: 417 KB], and visit the FAQs page to find answers to many questions related to both the MPN and vital stain method.

1. Ballast water management systems that render organisms non-reproductive and harmless meet the spirit and letter of the Nonindigenous Aquatic Nuisance Prevention and Control Act (NANPCA), National Invasive Species Act (NISA), and USCG Final Rule. Read more…

2. Low-energy UV-based ballast water management systems are safe, well-established for protecting human health and the environment, and more “green than other systems. Read more…

3. UV-based ballast water management systems are the most effective for use in fresh water, as they are not adversely impacted by salinity. Read more…

4. MPN is an appropriate test method for all ballast water management systems, and is widely-recognized as accurate, practical, and protective. The vital stain method is not practicable or applicable for UV. Read more…

5. Accepting the MPN method will harmonize U.S. and international ballast water regulations, and benefit the shipping industry. Read more…

Effect Change

Together with concerned citizens, environmental groups, shipowners, marine organizations, and manufacturers, let’s urge the USCG to reconsider its decision.

Send a letter to the USCG