Aquatic Invasive Species in U.S. Waters

The spread of aquatic invasive species is now recognized as one of the greatest threats to the ecological and the economic well-being of the planet. The direct and indirect health effects are becoming increasingly serious, and the damage to environment is often irreversible. The global economic impact of invasive species has been estimated to be ~$100 billion per year.

Several types of ballast water management systems have been developed to eliminate the problem of aquatic invasive species in ballast water. Systems using ultraviolet light (UV) are effective and inherently safe, as they utilize physical treatment technologies. In contrast, chlorine-based systems increase environmental risk, due to the potential for chlorine discharge and formation of disinfection by-products.

Ballast Water Management Guidelines and Regulations - International vs. USCG

The International Maritime Organization (IMO) adopted the Ballast Water Management (BWM) Convention in 2004. It will enter into force on September 8, 2017.

57 ballast water treatment systems have been Type Approved under the IMO, meaning that representative equipment and testing data have been evaluated and approved to meet IMO ballast water standards. 26 of these 57 systems are UV-based (a significant number), and the biological efficacy of the majority of them was determined using grow-out methods, including the MPN method.

In addition to meeting IMO ballast water requirements in ports all over the world, vessels sailing in U.S. waters are also required to adhere to USCG ballast water discharge standards and regulations. However, if the USCG refuses to accept the testing protocols used throughout the world (i.e., the MPN method), a conflict will be created that is likely to delay the installation of approved ballast water management systems.


Here is an overview of USCG ballast water management regulations:

Applications for USCG Type Approval

In March 2015, Trojan Marinex, DESMI Ocean Guard, and Alfa Laval submitted Type Approval applications to the USCG. To date, these three organizations are the only ones to submit such applications, having completed all necessary shipboard and land-based testing. The systems offered by these organizations utilize filtration and UV radiation to treat organisms in ballast water, thereby removing or rendering them non-reproductive, and thus unable to grow, colonize and cause an infestation or nuisance.

However, the USCG has interpreted the U.S. regulations to specifically require ballast water management systems to be evaluated based on their ability to kill certain organisms before they are discharged, even if they are rendered non-reproductive before discharge. Instead of testing for reproductive ability of organisms in treated ballast water (and the threat of colonization), the ETV Protocol employs a vital stain method that tests for the presence of enzymatic activity as a proxy for whether organisms in the water appear to have been treated to the point of immediate death.

During the development of the Final Rule, the USCG anticipated that new testing methods and approaches would arise over time. Therefore, 46 CFR 162.060-10 (b)(1) allows the USCG to consider proposed alternative approaches to the published testing requirements.

Applications for Approval of MPN

Starting in 2014, Calgon Corporation subsidiary Hyde Marine, Trojan Marinex, DESMI Ocean Guard, and Alfa Laval filed applications for acceptance of the MPN method as equivalent to the vital stain method.

These applications provided:

  1. An explanation of why the current method (i.e., vital stain) is not practicable or applicable.
  2. Information to support that the alternative method (i.e., MPN) is equivalent to existing requirements.

On December 14, 2015, the USCG rejected all four applications for use of the MPN method and, simultaneously, the three pending Type Approval applications. The two-page rejection letter relies upon an arbitrary and capriciously-narrow interpretation of the availability of alternative tests and, in so doing, irrationally disregards the USCG own mandate to establish and enforce regulations to prevent the introduction and spread of aquatic invasive species.

There is no scientific dispute that destroying an organism’s ability to reproduce is an effective means of preventing and controlling aquatic invasive species.

To date, the USCG has yet to grant Type Approval to a low-energy UV-based ballast water management system that is capable of treating poor quality water at ports throughout the world. The USCG’s decision to reject the MPN method will negatively impact shipowners, the environment, legislators, international policymakers, marine consultants, and concerned citizens.

Together, let’s urge the USCG to reconsider its decision.

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