limitations of all links (i.e., their ability to absorb additional demands without straining capacities) and a further assessment of the diversion possibilities. For the latter, one would need to know whether, absent an ability to use the seaway, an exporter (importer) has an alternative market (source) in the event that the alternative transportation mode proved too expensive. As discussed in the following paragraphs, a review of the literature suggests that partial answers are available to some of the relevant questions, but the comprehensive analysis needed to quantify with confidence the economic impacts of closing the seaway to transoceanic vessels is lacking.

The study by Taylor and Roach (2005) probably comes closest to an overall assessment (see Box D-1). To the committee’s knowledge, it is the only study to date that offers an estimate of handling and transportation cost savings attributed to transoceanic vessels transporting cargoes via the seaway. The study’s principal conclusion is that a cessation of transoceanic shipping on the Great Lakes would result in a transportation cost penalty of approximately US$55 million annually.

The committee notes that the Taylor and Roach estimate does not include the transportation cost savings associated with coastal vessels that move goods between Great Lakes ports and coastal ports within the Canadian and U.S. exclusive economic zones (EEZs). These vessels are also a possible source of aquatic invasive species (AIS), as discussed in Chapter 4.3 The vessel traffic data from the seaway corporations include coastal vessels within the “laker” category, but the coastal component of the laker traffic cannot be readily extracted. Thus, assessing the transportation cost savings for coastal vessels using the seaway is problematic.

The methodology of Taylor and Roach is analogous to that of earlier researchers who have faced similar questions, and consequently the study has shortcomings often attributed to these types of efforts. In particular, these analyses fail to consider a spatial


Contrary to recent evidence, Taylor and Roach state that “aquatic invasives are introduced by oceangoing vessels, and not by lakers that remain within the North American EEZ” (2005, p. 6).

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