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Abstract PAST, CURRENT AND FUTURE ROLE OF THE PANAMA CANAL IN REGIONAL AND GLOBAL COASTAL INVASIONS. Mark E. Torchin1 and Gregory M. Ruiz2 Biological invasions cause billions of dollars of economic damage
each year and are a serious threat to native biodiversity. Once
established, introduced species can become numerically or functionally
dominant in invaded communities, altering ecosystem processes, impacting
economies, and affecting human health. In marine and coastal environments,
ships are a major transfer mechanism of introduced species. However,
what controls or limits the extent of invasions in any region remains
poorly understood. Dramatic variation exists in the establishment
and demographic success of non-native species in different regions.
Several hypotheses aim to explain this geographic variation, including
differences in (a) the supply of organisms (propagule pressure)
delivered to a region, (b) the environmental compatibility of arriving
organisms, (c) frequency and magnitude of disturbance in the new
region and (c) biotic interactions such as predation, parasitism
and competition which may limit invasions. Panama is an important
focal point for the study of ship-mediated marine and coastal invasions
and provides the opportunity to evaluate hypotheses about invasion
dynamics. The Panama Canal serves as an aquatic corridor between
the Atlantic and Pacific oceans. Since its opening in 1914, approximately
800,000 ocean-going commercial vessels have passed through the Canal.
Recently, the annual number of commercial ship transits exceeded
twice the number of ship arrivals in the largest U.S. ports. This
suggests that the potential supply of organisms associated with
ships may be relatively high, yet reports of marine invasions are
limited in this tropical region. Current plans for expanding the
capacity of the Panama Canal and Panama’s ports will increase
shipping and the potential for invasions. We are evaluating how
shipping and biotic processes interact to facilitate invasions in
the Panama Canal and how this can elucidate processes driving marine
and coastal invasions in general.
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