By Rachel Meyer, Sam Fleming, Emily Gardiner A Response to Invasive Species in the Lake Champlain Basin By Rachel Meyer, Sam Fleming, Emily Gardiner

The Problem with Invasive Species The presence of aquatic and terrestrial invasive species poses several concerns such as: - loss of native species -alteration of habitats, -over-exploitation of resources -competition for ecological niches *Economic and Ecological Consequences!

Invasive Species in the Lake Champlain Basin -over 48 invasives in VT alone! -lots of research/data on these species in particular -an effort to increase productivity with amount of time

   Invasive Highway

Purple Loosestrife Lythrum salicaria  

Purple Loosestrife Lythrum salicaria -herbaceous, perennial plant -can grow up to 10 ft tall -thrives in wetland areas -populations have been spreading at a rate of 155,000 ha/year in U.S. -costs up to $45 billion/year in U.S. for control methods and forage losses -present mostly along CT River and within Champlain Basin -1989, 1996, 2005 distributions in VT

Purple Loosestrife Lythrum salicaria -can  adapt easily to varied soil conditions -can assimilate much higher amounts of carbon than other plants -establishes in low-fertility soils -competes for pollinators -extensive seed dispersal

Purple Loosestrife Lythrum salicaria Control Efforts: -invasive plant quarantine April 2002 -biological control: Galerucella spp. -chemical control -prevention -education -increased enforcement

Eurasian Watermilfoil (Myriophyllum spicatum L.) Notes

Eurasian Watermilfoil Introduction Non-native aquatic plant First noted in Lake Champlain in 1962 Known for rapid growth and spread Commonly found in shallow bays and along the shoreline Form dense beds No known methods for eradication

Eurasian Watermilfoil Ecology Native to parts of Europe, Asia, and northern Africa Native types of milfoil rarely grow as fast Stems can reach surface in up to 20 feet of water Will readily grow in many lake substrates (i.e. silty, sandy, rocky) Reproduce from fragments

Eurasian Watermilfoil Control Education State laws and regulations Bottom barriers Diver operated suction harvesting Hydrorake Pulling by hand Mechanical harvesters Rotavating Aquatic herbicides Biotic controls

(Alosa pseudoharengus) Alewife (Alosa pseudoharengus)

Alewife Introduction Native to the Atlantic Ocean Invaded the Great Lakes in 1931 and caused dramatic decline in native planktivore populations First discovered in VT in Lake St. Catherine in 1997 First noted in Lake Champlain in Missiquoi Bay in 2003...population expanded rapidly in 2007 and 2008

Alewife Ecology Population grows relatively unchecked due to low predator populations Experience seasonal die-offs because not well-adapted to fresh water environments Outcompetes many native planktivorous fish Feeds on eggs and larvae of important game fish Predation on alewife results in Cayuga syndrome - increases fry mortality

Alewife Control Netting Predation Chemical - Retenone and Antimycin 

Water Chestnut Forms dense surface mats Native plants can't compete     Trapa natans L. Forms dense surface mats  Native plants can't compete Planted intentionally in the late 19th century Seen in Hudson river in 1920, LCP in 1940 5.8 million spent to erradicate in LCP 1982-2004

     Water Chestnut Locations Notes

Grow on any hard surface Highly efficient filter feeders  Zebra Mussels Dreissena polymorpha dcvx   Grow on any hard surface Highly efficient filter feeders Environmental impacts Good and Bad Economic impacts $65K a year, over 2 million already spent. Tourism

What Can Be Done? Good question... Education Fines ($500) Observation Preventative measures Aquatic competition

Habitats and Rank: Effects Link (0, 0.5, 1.0) Species Open Water <6’ Open Water >6’ Rivers / Streams Develop-ed Forest Herb-aceous Ag Wetlands Alewife 1 E. Milfoil Zebra Mussel 0.5 Purple Loose-strife Water Chest-nut IS total .5

Habitats and Rank: Impacts Link (0, 0.5, 1, 2) Species Open Water <6’ Open Water >6’ Rivers / Streams Develop-ed Forest Herb-aceous Ag Wetlands Alewife 2 E. Milfoil 1 Zebra Mussel Purple Loose-strife Water Chest-nut IS total .5

Sources and Stressors (0, 0.5, 1, 2) Ag Urban Roads Forest Fisher-ies Marinas Dams Parks Indust. Ex. 1 2 0.5 *Total across the board instead of breaking into categories

Acknowledgements A special thanks to Meg Modley and Ellen Marsden!