Aquatic Exotics In Wisconsin A Presentation Developed by Wisconsin Sea Grant Advisory Services October 2006
Aquatic Exotics In Wisconsin Wisconsin has become host to several aquatic species that never existed here naturally Some Atlantic Ocean species came in through the Welland Canal: Lampreys, 1930 s Alewife, 1949 White perch, 1989 Three-spine stickleback 1991
Aquatic Exotics In Wisconsin Some were intentionally introduced: Chinook and Coho salmon 1963 Rainbow trout 1963 Brown trout 1960 s Carp in 1880 s
Aquatic Exotics In Wisconsin Some escaped from lakes, ponds or as bait: Smelt Goldfish Grass Carp Rusty Crayfish Purple Loosestrife
Aquatic Exotics In Wisconsin Some recent invaders came in the ballast water of sea-going ships: Ruffe in 1986 Zebra Mussels in 1988 Spiny water flea in 1990 Round goby in 1995
Aquatic Exotics In Wisconsin Invasive species traits: High reproductive rate Mature quickly Eat various types of food Tolerate poor water quality Easily adapt to new habitats
Aquatic Exotics In Wisconsin Native species traits: Have narrow food preferences Require certain spawning habitat Intolerant of poor water quality
Aquatic Exotics In Wisconsin A Quick look at six recent invaders: Zebra mussels Round goby Ruffe Purple loosestrife Eurasian milfoil Spiny water fleas
Zebra Mussel Max. size ~ 2 * Introduced via ballast water from Europe * First found in Lake St. Claire (MI) in 1988 * Eats plankton, filters up to 1 liter of water per day * Produce 40,000 eggs/year * Densities up to 700,000 per sq. meter = 43,000 on a piece of notebook paper * Spread easily via planktonic larvae and adults stuck on weeds and boats
Zebra Mussel Life Cycle Planktonic up to 1 month Veliger Post Veliger Egg 3-5 Days Microscopic Can be seen Adult 4-5 Years Can be felt Juvenile Byssal Threads Settle and attach to substrate Wisconsin Sea Grant Advisory Services
Zebra Mussels Colonize Lots of Things
Zebra mussels get moved to new lakes by water in and weeds on boats.
Zebra Mussels 2006 (24 counties, 79 lakes)
Wisconsin Lakes With Zebra Mussels Total Number 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Why the big jump in 2006? Better monitoring and additional infestations 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 79? Year
Ruffe 3-4 Long S. Zienert Max. 10 First found in 1986 in Lake Superior Introduced via ballast water from Southern Europe Affects perch, whitefish and minnows Eats fish eggs, bottom-dwelling insects and worms Now Present in Lakes Superior, Huron and Michigan
Round Goby 3-4 Long Max. 10 Introduced via ballast water from Europe Affects sculpins and other bottom-dwelling species Eats fish eggs, bottom-dwelling insects and worms Present in all the Great Lakes, Chicago River
Purple Loosestrife 4-Sided Stem 2 Million Seeds per Year Displaces Native Vegetation Destroys Habitat Controlled by: Physical Removal Beetles
Galerucella beetles: biocontrol for purple loosestrife
Purple Loosestrife
Eurasian Watermilfoil - Displaces native vegetation - Clogs boating and swimming areas - Spread by boaters through fragmentation Control: Northern milfoil beetle Chemical
Eurasian milfoil compared to Northern milfoil
Eurasian Milfoil Present in: 62 counties > 475 waters
Rusty Crayfish Native to southern U.S. Introduced with bait Aggressive Destroys vegetation as they feed Displaces native crayfish Present in many Wisconsin lakes Often spread as bait
Rusty Crayfish Documented Suspected
Spiny Water Flea - BC & CP Bythotrephes cederstroemi & Cercopagis pengoi 5mm Long Max. 1/3 Long spines make them hard for fish to eat Foul fishing lines and nets (look fuzzy or gooey) Introduced via ballast water from Europe Present in all the Great Lakes and Gile Flowage in WI
Preventing The Spread Drain bilge water Dispose of live bait Clean off weeds
If You Catch An Aquatic Exotic KEEP It: Put it in a plastic bag or foil FREEZE It: REPORT It: Put it in a freezer or ice chest Call: Wisconsin DNR or Wisconsin Sea Grant
Aquatic Exotics In Wisconsin How Can You Help? Learn To Identify Them Report If You Catch One Know Their Effects on the Ecosystem Prevent Their Spread Teach Others
For More Information Visit the Sea Grant Nonindigenous Species Sites: www.sgnis.org www.seagrant.wisc.edu Or Call: Wisconsin Sea Grant (920) 683-4697 Wisconsin Department of Natural Resources (608) 266-9270