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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 2008 and is updated daily.
It provides geographical and historical information to show distribution
over space and time. The reports came 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
digitized in 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. 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 mussels are represented with larger red markers. Click on a marker for
more information. For quagga mussel distribution, click
here. To REPORT an observation or collection of mussels, click here.
Suggested citation: Benson, A. J. 2008. 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