Next to Naught: Cleansing Ballast Water
"Looking for ten zooplankton in a cubic meter of water is on the same scale as looking for ten golf balls in 594 Empire State Buildings," said Lisa Drake. She should know. Drake is a physical scientist working with the U.S. Naval Research Laboratory in Key West, Florida, and is the lead biologist in a team developing procedures for verifying that ballast water treatment systems purge practically all life from the water in a ship's ballast tanks.
Verifying that fewer than ten zooplankton are floating in over 260 gallons (1 m3) of ballast water has become an increasingly sincere goal, not only for Drake, but also for the global and Great Lakes maritime industries, and various federal and state governments. Although it is conceivable that rogue individuals might be able to establish a new population, the premise is that nearly eliminating life from ballast water will dramatically reduce the risk of spreading aquatic invasive species through commercial shipping.
Ballast water is a necessity that stabilizes an empty or partially loaded ship, particularly in rough seas; it is also the presumed vector that introduced possibly up to 48% of the non-native species found in Lake Superior. Within the Great Lakes, shippers are following voluntary best management practices for ballast water and even modifying the water intakes on some vessels. Ships arriving from the open ocean exchange their ballast water before entering the Seaway.
The United Nations' International Maritime Organization (IMO) estimates that the world's commercial vessels can unintentionally transport thousands of different species in their ballast tanks. The IMO ignited the hunt to kill organisms in ballast water in 2004 when it adopted The Convention*. As The Convention nears ratification, new and existing ships are being outfitted with ballast water treatment systems promising to meet the IMO ballast water discharge standard, defined as less than ten living organisms ≥ 50 micrometers (about the size of a speck of dust) per cubic meter of water. Different thresholds apply to microscopic organisms and pathogenic microbes.
The IMO discharge standard and pending ballast water regulation in the United States raise questions about what specific standards can be achieved, in what conditions they can be achieved, and how anyone can be confident that they are being achieved.
"Ballast water treatment system vendors want to kill everything," said Mario Tamburri, research associate professor with the University of Maryland and director of the Maritime Environmental Resource Center (MERC) at a spring meeting of the Great Lakes Ballast Water Collaborative. Continuing he said, "They can't. You don't necessarily need to make a target for them to shoot for. They're already shooting for zero."
Tamburri serves with Drake on the U.S. Environmental Protection Agency's Environmental Technology Verification (ETV) program's technical panel on ballast water treatment testing. The panel crafted protocols for standardized testing that are nearing final clearance. The protocols promise to accelerate the U.S. Coast Guard's much-anticipated final ruling about ballast water treatment standards, which was slowed by quality assurance and quality control issues.
Ballast water management is a particularly sensitive issue in the Great Lakes. Shippers are voluntarily implementing practices to minimize the spread of aquatic species and Great Lakes states have crafted a mosaic of legislation in hopes of speeding the industry's progress toward this goal. The momentum morphed into the Great Lakes Ballast Water Collaborative in 2009. The Collaborative grew from the need to be more intentional about communicating as ballast water regulations became more layered, nuanced, and imminent. Partners in the Collaborative are also working to improve the ability of ship owners to comply with ballast water regulations, and advance the state of ballast water technology in freshwater environments.
Dale Bergeron, Minnesota Sea Grant maritime extension educator, helps to expedite the flow of information among the Collaborative participants and beyond. He said, "Applying the IMO discharge standard to freshwater environments brings up a surprising host of challenges. Regulatory and installation issues aside, we're discovering that some ballast water treatment systems developed for use in saltwater are not necessarily appropriate for fresh water, mainly because the discharge can exceed water quality standards."
Bergeron facilitates Collaborative discussions, which involve scientists like Drake and Tamburri, Canadian and U.S. fleet owners, state and federal (U.S. and Canada) regulatory officials, ballast water treatment system developers, and even the insurers of ships, who also have a stake in the safe functioning of the vessels. The Collaborative has met twice this year. The primary impetus was to compile information for Wisconsin lawmakers as they consider implementing a ballast water discharge standard 100 times more stringent than the IMO's. The majority of the group concluded that the IMO discharge standard (e.g., < 10 zooplankters per cubic meter) could be met with reasonable confidence, but that demonstrating a ballast water treatment system was performing to the more stringent standard would be exceedingly difficult, if not impossible, at this time.
The Collaborative's summer meeting in Duluth, Minn., included a site visit to the Great Ships Initiative's ballast water treatment testing facility (the world's only facility located on an entirely fresh body of water). It also involved a push from researchers to organize a database where vendors and testing facilities could easily share information about their testing. The scientists are interested in methods data such as temperature, turbidity, and salinity.
The Collaborative's discussions, both at formal meetings and through ongoing phone and e-mail exchanges are also tackling regulatory issues and the very real physical and temporal challenges of actually installing ballast water treatment systems aboard Great Lakes ships. To learn more about the Great Lakes Ballast Water Collaborative's activities, which are supported by the U.S. Saint Lawrence Seaway Development Corporation (The Seaway) in conjunction with the International Joint Commission, log onto The Seaway's Web site at: www.greatlakes-seaway.com/en/environment/ballast_collaborative.html.
By Sharon Moen