Exotic Aquatic Plant Watch Training – Protect Michigan’s Lakes!


“If you’re a boater, angler or really
anyone who enjoys the water, you’ve probably dealt with weeds in Michigan lakes. The Exotic
Aquatic Plant Watch is part of Michigan’s volunteer Cooperative Lakes Monitoring Program.
The purpose of this program is to provide you with a strategy for monitoring for extremely
troublesome invasive aquatic plants, so you can detect early infestations of these damaging
species. If detected early, weed management strategies can be used to reduce the chance
that the invaders will significantly impact the lake ecosystem and recreation. In this short video, we will provide you with
an overview of how to conduct the exotic aquatic plant watch on your lake. Stay tuned to learn
how to determine where to sample, how to collect and identify priority invasive plants and
how to report your results” Music
“Let’s start by taking a look at a few of the invasive aquatic plants that the Exotic
Aquatic Plant Watch program focuses on. While there are several non-native invasive plants
in Michigan’s lakes, four that pose a particularly high risk are: Eurasian watermilfoil, curly-leaf
pondweed, starry stonewort and hydrilla. Now let’s learn how to identify each of these
invasive weeds.” “Eurasian watermilfoil already can be found
in hundreds of Michigan’s inland lakes. It forms a dense mat of vegetation at the
water surface dramatically hindering fishing and recreational use of the lake. It reproduces
very effectively by vegetative fragments, so it easily spreads to other parts of the
lake or to other lakes by hitchhiking on boats and trailers. There are several native, valuable
species of NATIVE milfoils in Michigan and so it’s important to distinguish between
the native and the Eurasian species. “ • The easiest way to tell E. milfoil and
our native milfoil from other plants is to look at the leaf. There are usually four leaves
at each node of the plant. Looking at one leaf it resembles a feather or a child’s
drawing of a Christmas tree. No other plant has a leave of this shape. The best way to
tell E. milfoil from the native milfoils is to count the number of leaflets on one side
of a leaf. E. milfoil will have more than 12 leaflets and native milfoils will have
12 or less. • The native and the Eurasian milfoil can
and do hybridize, displaying physical features of both species and causing increased problems
during treatment efforts. The only way to identify a hybrid milfoil is genetic testing.
CLMP staff can help you identify this option if your monitoring your lake in this program.
“Curly-leaf pondweed is an invasive plant that was introduced intentionally to Michigan
lakes in the 1800s to provide fish habitat. It is not a nuisance in every lake where it
appears, but it can be problematic, especially in disturbed areas.”
• Curly leaf grows earlier in the season then most of the other aquatic plants, appears
reddish-brown in the water and has wavy, stiff and crinkled –or curly- looking leaves.
• Curly leaf pond weed is the only pondweed variety that has leaf edges with little teeth,
or serrated edges. These serrated edges make the leaf look wavy just like lasagna noodles.
• There are some native pondweeds that look similar to Curly-leaf when they are in the
water, but closer inspection of leaf edges will determine for sure if the plant you have
is native or the invasive curly pond weed. “Starry stonewort is an aggressive newly-discovered
invader to Michigan lakes, it can spread very quickly and blanket the lake bottom with a
dense mat sometimes growing up to 8 feet tall, and it can tolerate colder, darker water then
other aquatic plants. • Starry stonewort is actually a macra algae,
giving it a jointed, uneven appearance. It can be different shades of green, but when
stems are squeezed between the fingers it gives off a ‘popping’ or bubble-wrap feel
and sound. • The sure fire way to identify starry stonewort
is by the presence of white or tan star-shaped bulbils. These star structures are the reproductive
features of starry stonewort and are sometimes are the only way to identify it from native
look-a-likes. • A similar species to starry stonewort
is native Chara, or muskgrass. Both muskgrass and starry like to live along the bottom sediment
of lakes, but where muskgrass provides beneficial habitat to fish and insect, starry stonewort
does not. • Muskgrass is also a macro algae, but can
immediately be distinguished from starry stonewort by the smell. Muskgrass, like it’s name
implies, has a musky, or stagnant-pond-like smell to it. Starry will not contain any such
smell. Muskgrass will also not really ‘pop’ when the branches are squeezed between your
fingers, but it will just crunch and collapse and muskgrass will never have white star shaped
bulbils. • If you are having trouble identifying
Muskgrass from starry, send photos or samples to CLMP staff, we LOVE to help identify plants.
“Hydrilla has been called a “super weed” due to its aggressive growth habits. It can
grow up to 25 feet long, impeding water ways, outcompeting native species and it’s reproductive
structure, turions, can survive in sediments for many years before sprouting. Hydrilla
is not known to be in Michigan’s lakes, but is already impacting lakes in nearby states
like Ohio and New York.” • Hydrilla can be identified be bright green,
slender stems with single small leaves whorled around a central stem or axis.
• Leaves tend to be less than ½ inch long, with serrated or toothed edges. The central
vein, or midrib will also have spines or serrations that you can feel with your fingertip.
• Hydrilla is in the same plant family as our native Elodea (waterweed) so they look
very similar. The primary distinguishing characteristic to tell them apart is the number of leaves
at each stem node. Elodea usually has 3 and Hydrilla usually has 5 or more. Additionally
the Elodea leaf edges appear smooth with very fine toothed edges, while the Hydrilla leaf
edge is noticeably toothed. Also Hydrilla usually has spines on the mid vein on the
underside of the leaf, while Elodea doesn’t. • Hydrilla is the most threatening species
on your invasive plant checklist for the EAPW program. If you see hydrilla in your lake,
and confirmed the identity with CLMP staff, you should immediately report it to the DNR
Invasive Species Early Detection and Response Team as immediate actions need to be taken
for this serious aggressive weed. “Now that you are familiar with the four
invasive plants you will be looking for, let’s talk about how to conduct the survey itself.”
“Before heading out onto the lake to begin your survey, assemble the necessary equipment.
A list of equipment is included in the monitoring information packet. Instructions for building your own sampling
rake are included in the monitoring information packet, and is available on the MiCorps website.”
“Most lakes are too large to survey in their entirety. Instead, focus your survey efforts
on transects, or lines drawn perpendicular to the lake shore, distributed around the
lake. Be sure to survey around (1) boat launches,
(2) public parks and beaches, (3) inlets, and (4) quiet bays and coves where plant life
tends to flourish The number of transects you should survey
depends on the size of your lake. For example, if your lake is less than 100 acres in size,
plan to survey 5-15 transects, if your lake is more than 100 acres plant to sample about
15-20 transects….look in the CLMP manual for more specific instructions.
“The best time of year to sample is at the peak of the growing season – usually July
to early August. (Wait too long into summer and you might miss curly leaf pond weed, wait
too long into fall and plants start to die back and disintegrate.)
It’s a good idea to have at least two people in the boat, both for safety, and to sample
efficiently and divide up the tasks of driving the boat, collecting the plants, and recording
data. Everyone can help identify the plants.” “Now you are ready to begin. Navigate to
your first sampling location. While navigating, the data recorder can fill out the top of
the data report cover sheet. Once you have arrived, use a sampling rake to collect plants.”
Volunteers talking and while sampling and looking at plants
“Record any invasive plants from the project list that you find. Look around the area to
see if there are any plants that were missed by your rake. You can disregard any other species of plants
that you find. You may also wish to photograph plants you
find for future reference or if you need help identifying that species. Sending electronic
photos of a plant on a scale sheet (or in your hand) is easier than sending a specimen.
Make sure the photos are clear, sharp and show the leaves or branching features of the
plant close up. There is no limit to the number of electronic images you can send us. If you are uncertain, place a sample of the
plant you are unsure about in a ziplock bag. Label the bag with the location where it was
found. “Continue sampling until you have surveyed
all locations. If you add any locations while you are surveying, be sure to give them a
number and make note of them. If you are working on a large lake, or a lake
with heavy plant growth, you may not be able to complete the survey in a single day. That’s
okay – just record the days you worked on the survey.”
If you are uncertain of the identity of some of the plants you collected, contact CLMP
staff for assistance. They will want to see photographs or samples of the plants for identification.
If you are asked to send in samples, keep them fresh by storing them in your refrigerator,
wrapped in damp paper towels, in a ziplock bag.”
“Your completed report is due to the CLMP program by the end of October. What if you didn’t find any invasive weeds
in your lake? That’s great news, and the CLMP wants to hear about it! If you don’t
find any invasive plants, check the box on the report cover sheet, and you are done! If you did find invasive plants, submit your
cover sheet, list of species locations, and any supporting information (maps, photographs)
to the program contact listed in your monitoring procedures. If you have any questions or concern about
finishing your survey or submitting your data, please contact the CLMP staff by email or
phone. We would LOVE to hear from you and are here to help.”
“Your observations will help you keep watch over your lake, discover new invasions if
they appear, and enable you to act quickly to control them if they do. Annual monitoring is recommended, so any new
infestations can be discovered before they damage your lake. The effort you have spent monitoring your
lake for invasive plants is an investment in the future of your lake, and in the health
of lakes across Michigan.” “To enroll your lake in the Exotic Aquatic
Plant Watch, or to learn more about this and other volunteer monitoring opportunities in
Michigan’s Cooperative Lakes Monitoring Program, visit the Michigan Clean Water Corps
website.”

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