Globalization of an Aquatic Pest: Economic Costs, Ecological Outcomes, and Positive Applications of Zebra Mussel Invasions and Expansions

The development of trade and tourism has been as important as the biological adaptations of zebra mussels and quagga mussels in mediating the historic spread of these organisms in Europe and their invasion of North America. Canals and increased commerce mediated the spread of zebra mussels in Europe at the beginning of the Industrial Revolution and facilitated their introduction to North America near the end of the 20th century. However, recreational boating is the most likely vehicle for the more recent intracontinental invasions of alpine and subalpine lakes in Europe and the recent leap of these freshwater mussels across the Continental Divide in North America. Although viewed as pests due to their biofouling effects, their economic costs to drinking water and electrical power plant companies have been smaller than once feared, and their negative impacts on other organisms have been smaller than predicted in the more than 20 years since the start of their invasion of North America. This review of recent publications reveals that positive outcomes of the presence of zebra mussels and quagga mussels have begun to be apparent, which help ameliorate the economic costs and negative ecological outcomes that have accompanied the globalization of this aquatic pest.