Ballast Water and Interdisciplinarity: A Complex Union

Michael Roy’15

“It’s a bird! It’s a plane! It’s…a zebra mussel?” Roughly thirty years ago, while sampling the Great Lakes, researchers stumbled upon a mussel that had never been seen in the Lakes before (Carlton, 1996). This particular mussel would result in billions of dollars in damage to infrastructure, and even more spent on eradicating this species (New York Sea Grant 1994). The bivalve in question was the Zebra Mussel; a relatively small freshwater mussel that will grow on practically any substrate and is native to the Black Sea (Carlton 1996). How did it get to the Great Lakes, you may ask? It was a question that took some time to answer, but once it was understood, the implications sent rippling effects throughout much of the world.

The culprit was ballast water, a seemingly innocent component to normal shipping practices. To maintain trim and buoyancy, large commercial tankers pump water from the surrounding harbor into specialized tanks found within their hulls (known as ballast tanks) (Carlton and Geller, 1993). Also contained within this water are dozens of different species, and thousands of individuals per species (Carlton and Geller, 1993). Once all cargo has been loaded, and enough water has been pumped into the ballast tanks, the ship leaves the harbor for its next locale. Therefore, along for the ride are many varieties of species ranging from worms, to crustaceans, to pelagic fish larvae (Carlton and Geller, 1993). These organisms often survive the trip to the next port, where they are released once the ballast tanks are emptied (to load more cargo) (Carlton 1999). This is the hypothesized vector of transport that brought the mussel to the shores of the Great Lakes (Carlton 1996). Transport by means of ballast (including rock and sand ballast) had been known for centuries prior (Carlton 1996). However, the zebra mussel brought the issue transport of non-native species by means of ballast into stark relief because of its major impact on the environmental health and infrastructure surrounding the lakes.

I first became acquainted with this system in the spring of 2011 when I attended the Maritime Studies Program of Williams College and the Mystic Seaport, in Mystic CT, fondly known among its alumni as the Williams-Mystic Program. Williams-Mystic is an undergraduate interdisciplinary program that integrates maritime culture, literature of the sea, marine history, maritime law, and marine science to understand the interconnected nature of these disciplines. As connected as the world’s oceans, the Williams-Mystic program understands the connected nature of many fields of study previously thought to be separate and distinct. As such, students from many different backgrounds and a variety of academic institutions attend the Williams-Mystic program every semester, truly learning the value of interdisciplinarity from their professors and each other to solve complex problems with multidimensional solutions.

While at the Williams-Mystic program, I focused on ballast water for my term paper in Maritime Law. Although the zebra mussel was an ecological issue, it also was an economic and political issue. To prevent the spread of any new species by means of ballast water, the state of New York in 2010 passed legislation that would require vessels to treat their ballast tanks with some chemical or ultraviolet light prior to entering the lakes to kill any organisms found inside the ballast tanks (Aquatic nuisance species coalition participation act S145-2011). At this point in time, commercial vessels already needed to flush their tanks in the open water with salt water if the water they were carrying was fresh (the salt water is thought to kill any freshwater organisms that could not tolerate high salinities). However, since many estuarine organisms have highly variable salinity tolerances, New York State believed that ballast water exchange was sampling not effective enough (Aquatic nuisance species coalition participation act S145-2011). Their law indicated that they would block any ships that did not meet their requirements from entering the lakes (Aquatic nuisance species coalition participation act S145-2011). Not only was this a domestic issue for the United States, it was also a geopolitical issue for Canada. Such legislation proposed by a US state would bar shipping through lake Erie the ports in Lakes Huron, Michigan, and Superior to a sovereign nation. New York has since backed off on some of its stricter requirements, appeasing any conflict with Canada.

However, understanding this complex and highly important issue required an understanding of multiple disciplines (a truly transdisciplinary issue) ranging from scientific, to political, to economic. This training instilled a desire to better understand complex issues from multiple perspectives in order to arrive at the best and most comprehensive solutions to a variety of multifaceted problems. Now that I am a Coasts and Communities Fellow in the Integrative Graduate and Research Traineeship (IGERT), I am able to hone in these skills, and learn in greater detail how to achieve these goals. Transdisciplinary and multidisciplinary programs are critical in today’s complex interconnected world, and truly need to be fostered in every aspect of society to solve the world’s most critical issues.


Aquatic nuisance species coalition participation act S145-2011 (2011) []

Carlton, J. T., Geller, J. B., (1993) Ecological roulette: the global transport of nonindigenous marine organisms, Science 261: 78-82

Carlton, J. T., (1996) Marine bioinvasions: the alteration of marine ecosystems by non-indigenous species Oceanography, 9:1

Carlton, J. T., (1999) The scale and ecological consequences of biological invasions in the world’s oceans, Invasive Species and Biodiversity Management, 195-212

New York Sea Grant 1994



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