The shores of Appledore Island, Maine – just six miles from
the New Hampshire coast – are being invaded by an aggressive red algae that can
foul popular tourist beaches and damage vital local fisheries.
The seaweed, Heterosiphonia japonica, is a native to Japan
and has not been reported elsewhere in Maine to date. The brownish-red stringy
plant was first spotted underwater on Appledore in 2011 by undergraduates in
the Shoals Marine Lab Underwater Research class. By this summer most of the
studied intertidal transects on the island – permanent sites between the high-
and low-tide lines – contained Heterosiphonia.