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| NAS - Nonindigenous Aquatic Species |
This map layer is a compilation of confirmed zebra mussel sighting
reports in the United States and Canada from 1988 through 2009 and is updated
daily. It provides geographical and historical information to show distribution
over space and time. Each sighting report does not necessarily represent an
established population, but for most locations it does. The reports come from
a variety of Federal, State, and municipal agencies, universities, public utilities,
engineering and private consultant firms. The locations of confirmed sightings
were registered at 1:100,000-scale on EPA Reach File Version 3.0 and are maintained
as an ArcInfo shapefile. These data are intended for geographic display and
analysis at the national level, and for large regional areas. Sightings were
reported with varying levels of accuracy. Some of the reports were as latitude-longitude
coordinates, some as river miles, and others as just a lake, beach, harbor,
or a water body and nearest town name. If no specific location was reported
in a lake, the point was assigned to the center. The data should be displayed
and analyzed at scales appropriate for 1:2,000,000-scale data. It is possible
that zebra mussels can be found at other locations not displayed here, but have
gone unreported to this effort. It is also possible that zebra mussels may not
persist at a particular site after the introduction through natural means or
eradication. No responsibility is assumed by the U.S. Geological Survey in the
use of these data. Acknowledgment of the U.S. Geological Survey would be appreciated
in products derived from these data.
Zebra mussel locations are represented with larger red markers.
Click on a marker for more information. (Because
of the large number of locations, the data may take some time to load.)
Also see the Quagga Mussel Distribution
REPORT an observation or collection of mussels.Suggested citation: Benson, A. J. 2009. Zebra mussel sightings distribution. Retrieved [add current date] from http://nas.er.usgs.gov/taxgroup/mollusks/zebramussel/zebramusseldistribution.asp.
For more information, contact: Amy Benson, abenson@usgs.gov