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How did Carex kobomugi get to New Jersey?

0945582943Its not known exactly how the Asiatic Sand Sedge reached New Jersey's shores.  Small (1954) speculated that the sedge was used to pack oriental china and that it was released to our dunes when a shipwreck resulted in crates of such china washing up on the Jersey shore and breaking open, releasing the sedge. However, its not clear what the basis of this assertion was, beyond the fact that the first population reported in New Jersey was at a lifeboat station at Island Beach State Park. In recent years I've spoken extensively with colleagues in Japan and the consensus is that this species was not ever used as a packing material.  There are several reasons for this. The first is that the plant is not that abundant in dunes in Asia.  Unlike the situation in the U.S. when growing in its native habitat, Carex kobomugi  rarely grows in a dense monoculture.  Nor does it show the extremely dense growth patterns that characterize the plant when growing on dunes here in the US.  Moreover, there's nothing about the plant that would make it a particularly good packing material.  Its not particularly spongy, so it wouldn't be something you'd go out of your way to collect as a packing material.  Indeed its sharp edges would make it unpleasant to handle for those packing the shipments.  Thus it seems unlikely that it would have been used as a packing material.

So, if the original story of this species' arrival in New Jersey is probably incorrect, how DID it get here?  My best answer to that question is that it came in as a side effect of the use of solid ballast to stabilize ships when they sailed to a part empty  in order to pick up a cargo at that location.  Today's ships have ballast tanks designed to be filled with water when a ship sails empty, and this ballast water is a major source of aquatic invasions today.  But 100 years ago there were no ballast tanks.  Thus, when a ship sailed empty, sailors often would fill the cargo holds with anything heavy... rocks, sand or whatever was near to hand.  Presumably any plants, seeds or other biological materials that were in that sand would be loaded into the boat along with the sand, and sand sedge seeds seem a likely candidate for getting caught up in such a transport pathway. I suspect that either a ship carrying sand ballast wrecked off Island Beach State Park, releasing the sand, along with the sedge plants or seeds, or a crew trying to avoid the fees charged by the ports for disposing of such ballast, offloaded their ballast over the side of the ship as it entered the coastal water on the way to the Port of Newark or similar local docking point.   Either way, its not hard to imagine that seeds or even surviving shoots of the Asiatic sand sedge might have washed up on the Jersey shore and taken root here. 

Author: Louise Wootton. Ph.D.  Last updated June 17, 2009

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