Sightings Elsewhere

From July 26, 1991 (update #9)

HARDIN, Ill. -- Four separate sightings of individual zebra mussels in late June in the lower Illinois River confirmed the entry of zebra mussels into the Mississippi River drainage system. Three adult mussels were found attached to native clams by commercial clammers at locations ranging from 200 to 250 miles (320-400 km) downstream from Chicago. A fourth mussel was found by a youngster angling in the same area, which is within 50 miles (80 km) of the Mississippi River just upstream of St. Louis, Mo. The mussels sightings were confirmed by personnel at the Forbes Biological Station operated by the Illinois Natural History Survey (INHS). All of the zebra mussels were 3/4 to one inch (1.9-2.5 cm) long. The three mussels found by clammers were attached to native three-ridge mussels (Amblema plicata), a species whose pure white shells are worth $1 to $2 per pound as raw starting material in the Japanese cultured pearl industry. The invader poses a serious threat to the native mussels, according to INHS personnel.

DULUTH, Minn. -- A single adult zebra mussel was found on June 17 attached to a native clam by an angler fishing in the St. Louis River six miles upriver from Lake Superior, according to Minnesota Sea Grant field agent Jeff Gunderson. The mussel was approximately 0.9 inches (2.3 cm) long. This marks the furthest inland sighting to date in the Lake Superior basin.

ID: 19910726-4.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.