Analyzing trends in ballasting behavior of vessels arriving to the United States from 2004 to 2017.

Maritime shipping transports over 90% of global goods. Ballast water, used to provide vessel stability, has been associated with the introduction of marine invasive species. Thus, understanding ballasting trends is imperative to protecting human and environmental health. This paper examines data from the National Ballast Information Clearinghouse to assess ballasting behavior and shipping trends in the United States. From 2005 to 2017, vessel arrivals have remained relatively constant (annual growth rate of 1.2% per year) while total ballast discharge per vessel has grown at an annual rate of 7.6%. Furthermore, from 2014 to 2016, alternative ballast water management methods have been on the rise, and these treatment options are likely to continue increasing in response to the International Maritime Organization Ballast Water Management Convention that entered into force in September 2017. It is critical that the shipping industry monitors potential cascading impacts on other ballasting behaviors stemming from this shift.