NUISANCE(s)

Eurasian Watermilfoil

WHAT IS IT?  Scientific Name: (myriophyllum Spicatum) This Eurpoean, Asian and North African native is an aquatic submersed plant, usually growing in less than fifteen feet of water.  Eurasian watermilfoil has featherlike leaves arranged in circles of four on the stem, and tiny flowers that poke into the air.  Each leaf usually has more than twelve pairs of leaflets, and when out of water the plant is limp.  Branching is abundant in water three to ten feet deep.

EFFECTS:  Eurasian watermilfoil becomes a nuisance when it grows in dense beds and its foliage crowds the water surface, hindering recreational activities such as boating, swimming, and fishing.  These dnece plant beds cause a loss of plant diversity and fish habitat by crowding and shading out native species.

SPREAD:  This plant can spread quickly because of the fact that any individual fragment of the plant can take root and form a new colony.  Fregments can be transported by floating downstream, or by attaching to boats, propellers or trailers.


Zebra Mussel

LIFE CYCLE:  In the Great Lakes the zebra mussel life span has been observed to be a maximum of three years.  They become sexually mature at about one year of age.  Spawning is triggeres by factors like temperature and phytoplankton abundance.

EGG STAGE:  An average adult female can produce 30,000 to 40,000 eggs per season.  Eggs are released into the warm water and the male mussels sense the presence of the eggs around them and release sperm into the water.

VELIGER STAGE:  Sevearl hours after fertilization the larvae, known as veligers, emerge.  They have a clump of hair-like filaments called cilia that help suspend them in the water.  During this time they feed heavily on plankton and grow in size.

POST-VELIGER STAGE:  When they attain a size of about 200 um, the veligers are too heavy to remain afloat.  they settle on the bottom and try to find a hard surface to which they can attach.  Attachment of the post-veligers is made possible by byssal threads which are secreted.

SETTLING STAGE:  Within the next three weeks, post-veligers transform into juvenile forms.  These resemble adult mussels and attain maturity the following year.  Juveniles often detach their byssal attachment and move around, trying to locate areas with abundant plankton supplies.

ADULT STAGE:  A Zebra Mussel attains about 2.5 cm (1 inch) in the first year and adds abother 1.25 to 2.5 cm during the next year.

Purple Loosestrife

WHAT IS IT? Purple loosestrife is a plant that was accidentally introduced in to the United States and then distributed as an ornamental.  It is most easily identified during its flowering  period from July to September.  This spike shaped "purple" flower can be seen in ditches, streams, rivers, lakes, wetlands, and other moist, shallow water sites.  This palnt is an upright, hardy perennial, four to eight feet tall and most often found in a group.

EFFECTS:  Purple loosestrife invades marshes, ditches and lakeshores, quickly replacing cattails and other native wetland plants.  These plants form dense stands that ducks, geese, muskrats and frogs cannot use for food or cover.

SPREAD:  Purple loosestrife will grow from the roots of an established plant, however, the plants spread mainly by seed.  Having up to 300,000 per stalk, these tiny seeds can live in the soil and water for many years and can be transported great distances by humans, animals and water.  The seeds can be transported to other wetland areas via the mud on birds and ducks feet, in the fur of muskrat, mink and beaver, or on the shells of turtles.  Humans can also unknowingly transport the seeds via the mud on their shoes, boots, waders and clothing.

YOU CAN STOP THE SPREAD OF EXOTIC NUISANCES BY:
REMOVING
 any visible plants and animals from your boat, trailer, truck and other boating equipment (anchols, centerboards, rollers, axles, propellers, etc.) BEFORE leaving ANY water body.
DRAINING
 water from the motor, live well bilge, and transom wells at the ramp or access BEFORE leaving ANY water body.
EMPTYING
 your bait bucket on land before leaving any water body. NEVER release live bait into a water body, or release aquatic animals.
WASHING & DRYING
 your boat and other boating equipment to kill harmful exotic animal species that were not visible at the boat launch BEFORE transporting to another water body ~ ~ use one cap of liquid laundry detergent in bilge compartments and livewells.



Evans Lake Land Owners Association (ELLOA)
Last Updated:  2/23/08