Present Ballast Water Management Practices

Currently, ballast water exchange is the only effective management tool to reduce the risk of ballast-mediated invasion. Ballast water exchange involves replacing coastal water with open-ocean water during a voyage. This process reduces the density of coastal organisms in ballast tanks that may be able to invade a recipient port, replacing them with oceanic organisms with a lower probability of survival in nearshore waters.

Ballast water exchange is recommended as a voluntary measure by the International Maritime Organization (IMO). However, it is important to recognize two short-comings of this procedure. First, the ability to safely conduct ballast water exchange depends upon weather and sea surface conditions, and it is not always possible to perform an exchange. Second, there is still some residual density of coastal organisms in ballast tanks following exchange, so this process is only partly effective.

The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (P.L. 101-646) required that all vessels entering Great Lakes Ports from beyond the EEZ undergo ballast exchange or some comparably effective ballast treatment which conforms to discharge requirements of the Federal Water Pollution Control Act (33 U.S.C. 1251). These requirements were extended to vessels arriving in ports of the upper Hudson River, north of the George Washington Bridge on November 4, 1992.

The National Invasive Species Act (NISA) of 1996 (P.L. 104-332) reauthorized and amended the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990. NISA issued mandatory ballast management reporting and voluntary ballast exchange guidelines to all vessels that enter U.S. waters from outside the EEZ, with the exception of military vessels, crude oil tankers that carry out coastwise trade, and some passenger ships that are equipped with ballast treatment systems.

If compliance with the voluntary guidelines is low, NISA authorizes the use of mandatory guidelines for vessels arriving to selected regions or the entire country. The National Ballast Water Information Clearinghouse will provide data and analysis to estimate the national patterns of ballast water management. Policy decisions about the adequacy of voluntary guidelines and the acceptable rate of compliance will be based upon criteria and evaluation by a committee of the Aquatic Nuisance Species Task Force.