Pond Boss Forums INTRO Questions & Observations lily pads - our lake just got invaded

The north end of our lake just got invaded by a fast growing species of lily pad. Our lake is considered a closed system. That is there is no streams or rivers flowing into it. It�s fed by natural springs and city storm drains.

How would lily pads get introduced into a closed system like ours and what�s the most likely way they got introduced?

Could birds be the carrier?

What about fish stocking. Could a supplier have had lily pad seeds mixed in with water used to transport the fish that were stocked in our lake?

What about animals like beaver or nutria. Could they have eaten seeds from a river or pond nearby and redistribute them in our lake?

How would I identity the species of lily pad?

What is the best way to control them without hurting our other aquatic vegetation?

Birds, mammals, contamination in stocking water are all possible options. I am betting birds are the most likely candidate though.

Take some quality photos and post them on here. We can help you ID what you got.

Spot treating the lily pads with a liquid glyphosate formulation can be moderately effective on most water lily species. Glyphosate isa broad spectrum, systemic herbicide. Systemic herbicides are absorbed and move within the plant to the site of action. An aquatically registered surfactant will have to be added for good results.

A less selective option(it will kill other plants in the treatment area) but the most effective are 2,4-D compounds. 2,4-D compounds are also systemic herbicides. Instead of being a liquid that is applied to the leaf surface, it is in a granular form and spread over the water surface sinking to the bottom. There, the plants absorb the herbicide and die.

Al, with the drought we are having, I'm betting against city storm drains.

It's possible that one of the homeowners thought that they would look nice.

The lily pads first showed up 3 years ago. I observed about 8 pads the first year, about 16 the 2nd year and now in the 3rd year they have taken over an entire cove.

These pictures were taken 1 year ago. Click on the links.

http://i257.photobucket.com/albums/hh212...18/IMG_1788.jpg

http://i257.photobucket.com/albums/hh212...18/IMG_1789.jpg

http://i257.photobucket.com/albums/hh212...18/IMG_1790.jpg

http://i257.photobucket.com/albums/hh212...18/IMG_1791.jpg

http://i257.photobucket.com/albums/hh212...18/IMG_1773.jpg

Anyone know what species these are?

Al, what color are the flowers? Do you have a pic of any?

It doesn't look like anything here up North, but I'm sure someone can ID them.

You have American lotus. Generally, younger plants have "pads" that simply float on the surface. As they mature with age, they will have "pads" that raised up above the water's surface. This isn't always the case, some plants seem to never have "pads" that rise above the water's surface for one reason or another. Flowers are usually a creamy yellow, but can vary from almost pure white to a bright yellow in wild forms.

The advice I gave above reference treatment holds tree for lotus. They are gorgeous native plants, but will take over a lake if not managed...

I'll add that a widely fluctuating water-level allows American lotus to aggressively spread anywhere within the lake that sunlight adequately penetrates the water to sustain newly germinating seeds - which are often very abundant.
Also, topically applied liquid 2,4-D works quite well on lotus, providing that a very good surfactant is added (lotus pads shed water better than a duck's feathers).

I'm currently coordinating aerial applications against several extensive lotus infestations for the sole purpose of interupting the plant's seed production cycle. At least two additional treatments will be required next season for the same purpose - which is the only way to get ahead of this plant specie once it has reached "infestation level".
Depending on your lake's depth-profile, especially around its perimeter, a few patches of lotus are great (both aethetically and for fishing). But, if your lake has extensive areas of 4' or less in depth, be careful not to ignore this plants expansive nature.

Nice hat!

That isn't me wearing the "hat". Just thought I'd include one of the plant's practical uses.

Thanks everyone for the help identifying these pads. I went out yesterday and took some more pictures. So far I have not seen any flowers from these pads.

Pictures:
http://s257.photobucket.com/albums/hh212...2011/?start=all

Lake V - those are lotus leaves.