Effects of season and location on densities of zebra
mussel veligers in the Thunder Bay of Alpena MI



Wendy D. Kuehn
School of Science and Natural Resources
Lake Superior State University
Sault Ste. Marie, Michigan 49783



Abstract.    The zebra mussel (Dreissena polymorpha) began it's North America
invasion in Lake St Clair in 1988 and subsequently has spread rapidly northward to Lake
Huron. During 1995, the abundances of planktonic larvae (veliger) were monitored in the
Thunder Bay, Alpena. From June through September, zebra mussel veligers were
quantitatively sampled at five sites in the Thunder Bay. Three samples from each site were
collected weekly by using vertical plankton net tows ftom a 6 meter depth. Sample
densities of the Veligers ere determined for each collection date and site throughout the
summer. ANOVA/Tukey test results revealed significantly greater densities on July 25th.
A statistical difference between Whitefish Bay and Hardwood Point sites were found for
the time period. It was concluded that seasonal changes and site position both affect
veliger densities in the Thunder Bay.




Selected References

Garton,	D.W., and W.R. Hagg. 1993. Seasonal reproductive cycles and settlement
patterns ofDreissena polymorpha in western Lake Erie. Pages 1 1 1-128. Zebra
mussels biology, impacts, and control. CRC press, Boca Raton, Florida.

Mellina, E. and J.B. Rasmussen. (1994). Patterns in the distribution and abundance of
zebra mussel (Dreissena polymorpha) in rivers and lakes in relation to substrate
and other physicochemical factors. Canadian Journal of Fish and Aquatic
Sciences. 51: 1024-1036.