Re: Lessepsian migration, need of a separate term?

February 28, 2005
From: Cynthia Trowbridge

Dear Bill and Jim,
Hi! Interesting question [#13233] that Jim (and Nishina) have brought up. As a marine biologist working on introduced species, I would suggest that we not create more site-specific terms.

When Por coined the term "Lessepsian Migration", the phenomenon of introduced species was not widely recognized so the phrase was extremely useful. Now we are inundated with introduced species from many vectors (canals, container vessels, aquaculture, etc.) so site-specific terms are not particularly useful.

In a global review chapter of introduced macroalgae that I wrote for "Seaweed Resources of the World", there are numerous canal systems that have become invasion corridors to introduced species (despite any freshwater locks) including:

1. Suez Canal
2. Volga-Don Canal
3. Panama Canal
4. St. Lawrence Seaway

Here are a few *annotated* excerpts from my chapter:

The Suez Canal, connecting the eastern Mediterranean Sea and the Red Sea, was opened in 1869. Since then there has been dispersal of marine species through the canal, almost exclusively from the Red Sea to the Mediterranean; this movement of species has been termed "Lessepsian Migration" (Por 1978). Although the species' dispersal is natural (due to currents, etc.), human activities removed the geographic barrier separating the two biogeographical provinces; thus, these migrating species are considered introduced species.

The construction of numerous canals in Eastern Europe has permitted the spread of many invertebrates and fishes. For example, the construction of the Volga-Don Canal enabled species to move into the brackish Caspian Sea. This 101 km long canal with 13 shipping locks interconnected the Volga River (attached to the Black Sea) to the Don River (attached to the Caspian Sea). Many species have appeared in the Caspian Sea since the canal was opened in 1952.

The Panama Canal is another anthropogenic corridor through which Pacific and Atlantic species could move. Andrew Cohen and colleagues are currently surveying exotic marine species on the Pacific and Atlantic coasts in the vicinity of the canal to determine the importance of the corridor between biogeographic regions.

The St. Lawrence Seaway in eastern North America is a complex system of waterways, canals and locks linking the Great Lakes between Canada and the U.S. to the Atlantic Ocean. The seaway system is inter-connected by six short canals and nineteen shipping locks. There is a variety of species that have entered the Great Lakes from shipping (ballast water and/or hull fouling).

• Por, F.D. (1978) Lessepsian migration - the influx of Red Sea biota into the Mediterranean by way of the Suez Canal. Berlin: Springer Verlag.

Thank you for considering my plea for no more site-specific terms.

Cordially,
Cynthia

trowbric@onid.orst.edu

Trowbridge, C.D., 2005 (Feb 28) Re: Lessepsian migration, need of a separate term?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13240

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