Scientific name: Didymosphenia
geminata (Lyngb.) M. Schmidt
Synonym: Gomphonema geminata (Lyngb.) C.
Agardh
Common names: Didymo, Rock
snot
Native To: Northern Europe and northern North America (Vancouver Island)
Date of U.S. Introduction:
Was present in Canada in the late 1800s, but did not begin to cause
problems until the early 1990s. It was present in the rivers of the
Western U.S. by 2004, and it was first discovered east of the Mississippi
River in 2005 in Tennessee.
Means of Introduction: Exact
pathway unknown, but it spreads easily through contaminated boats
and fishing gear
Impact: Can result in dense
algal blooms that block sunlight and disrupt ecological processes,
causing a decline in native plant and animal life
Current U.S. Distribution:
Scattered populations exist throughout
the United States, including New England, the Mid-Atlantic
Region, and the Western U.S.
Not Wanted:
Didymo or Rock Snot (PDF | 143 KB) Maryland Department of Natural Resources.
Identification/Description; Photographs; Introduction History; Impacts; Distribution;
Legal Aspects
Didymo Environment Bay of Plenty Regional Council (New Zealand).
Identification/Description; Photographs; Impacts; Controls
Didymo New Zealand Ministry of Agriculture and Forestry. Biosecurity
New Zealand.
Identification/Description; Photographs; Introduction History; Impacts; Distribution;
Controls; Legal Aspects
Didymo Otago Regional Council (New Zealand).
Identification/Description; Photographs; Introduction History; Controls
