Pond Boss Forums AQUATIC VEGETATION Balance of plants in the environment Eelgrass

I am thinking about transplanting some eelgrass (Vallisneria americana) in my small pond (1/3 acre)for fish cover and Oxygenation.
Would appreciate suggestions and information from anyone who has had experience (good or bad) with this plant in ponds.

Larry

Larry - 1. Why did you choose eel-grass (tape-grass) to put in your pond?
2. Do you have any other plants in the pond?
3. How old is the pond?
4. What is the max depth?
5. What does your gereral water clarity? Is there a range of visibility thru the year?
6. Do you fertilize or feed the fish?
7. Can you tell us a little about how the eelgrass is growing where you are getting it?
How deep of water do you see it and how tall are the plants?
Lots of questions for you; hope this turns into a good discussion.
B.cody - The Pond Doctor

Bill,
I will try to answer your questions in the order you asked them.

1. Eelgrass is supposed to be a good oxygenator and I know that it provides cover for fish, it is easily available in a nearby river.
2. No
3. A little over a year old.
4. approximately 15 to 20 feet deep.
5. visibility right now is about 18 to 24 inches. It is greater in the winter and early spring, but the eelgrass does not grow then.
6. I feed the fish, but do not fertilize.
7. It is growing in a nearby river, depth from 1 to 5 ft (give or take). Length is around 3 to 5 feet.

Most of the pond drops off sharply around the edges, It was built by damming a small spring fed stream between two steep hills. Along one side there is a shelf of about 100' in length and 12' in width. Past this point there is another sharp dropoff to deeper water.The depth on the shelf is about 3', this is where I will plant the eelgrass. I am pretty sure that the eelgrass will not grow in the deeper water because of the lack of sunlight, so there should be no problem with the plant taking over the pond.
The pond is stocked with Coppernose Bluegill, Redear sunfish, Largemouth bass, Smallmouth bass, and a few channel cats. It is about 1/3 acre in size. I know that it is not recommended to stock bass in such a small pond, but I only have about 20 in the pond and they seem to be doing fine so far.
That's all I can think of right now. If there is anything else you would like to know, please ask.

Larry

HELP WANTED: Does anyone else have eelgrass / wild celery in their pond?
Give us your comments and experiences.

Larry - Your answers will help me formulate my comments about using eelgrass in your pond.

I am familiar with Vallisneria americania since I have had it growing in my two ponds for several years (abt 6 yrs now).
It is also called wild celery or tape-grass.
It is an oxygenator in the pond but most oxygen in all ponds comes from the phytoplankton community which grows in illuminated upper zone and limits light visibility in most ponds to 1-3 ft deep. These guys are the real oxygenators of aquatic systems.
Two of the sources I have says the eelgrass leaves can get 6 to 7 ft long. I have not seen it get longer than 24" to maybe 30" in my ponds. Your observation of it growing abt 5 ft long in the river agrees with the first two books I have.
I think I have two varieties or growth forms in my pond. One has a little wider & longer leaves and does not grow as densely but seems to grow a little deeper than the second type. Second type, has shorter leaves 6" to 18" grows in dense beds; some of the leaves in shallow water have a reddish hue. It grows about canoe paddle deep (5Ft.) Smaller pond water has visibility abt 2-3ft; clearer in fall, winter & real early spring.
There are two other types of Vallisneria in books/cataloges; both are said to grow as far north as zone 6 (considered tropical). Jungle - which has wide leaves abt 1" and corkscrew which has narrow twisted or spiral leaves. Corkscrew is supposed to have a maximum heigth of 8-12". Both are sold usu as aquarium/water garden plants. I've been experimenting with corkscrew for about a year and I did get it to overwinter in my pond, growing it in a dish pan (zone 5) under 2 months of ice cover. A neighbor has jungle eelgrass growing in his pond for about 4 years now. His jungle has leaves 2.5-3 ft long and grows in about 4-5 ft deep. His bed is about 40 ft long after 4 yrs; starting with several plants. His water has been abt 2-3 ft vis.
I am convinced that eelgrass will grow in water 10-12 deep probably deeper if the water is very clear. I don't see this as a problem if the plants stay short. Like with corkscrew eelgrass max height 12". Keep in mind that it will send scattered small 1-2" long flower "pods" to the surface onlong thin spiral stalks regardless of its growing depth. These are not a nuisance in my opinion; they only add fish cover and are at the surface for only about a month.
The book I have "Water Plants for Missouri Ponds" says that "Any fishing pond would benefit for a healthy stand of wild celery. This is one of the few submerged plants that provides good fish habitat but dosen't become rampant or interfere with fishing. Because it grows thickly it may even crowd out other less desirable underwater plants." I agree with this. It crowds out curly leaf pond weed in one of my ponds and the curly leaf is forced to grow in the deeper water; eelgrass dominates the shallow water. In the other pond it is crowding out beds of Chara.
In my old pond (which was rebuilt 3 yrs ago) now called the new pond, I had eel grass, narrow leaf pondweed & Chara. White amur ignored the eelgrass until spring then they "mowed" it all off across the bottom & I dipped most of the leaves out each spring. Amur must not have been able to eat many of the leaves and lots of it got away from the fish. I don't think eel grass is a favorite food of amur but they will eat it when nothing else is avilable. So eelgrass if too thick could be thinned or eliminated by amur depending on how many fish are in the pond.
With a thick stand of eelgrass in my pond I have no filamentous algae. Eelgrass seems to use most all the nutrients none left for algae. Eelgrass would not work if you fertilized your pond; the plants would prob. prevent a bloom. But I think dense beds of eelgrass use most of the nutrients from the fish manure from fish food. You can't plant eelgrass in a pond with amur; they eat it as fast as it is planted; my friend have tried this.
I think eel grass is excellant cover for small fish/minnows. Both of my ponds always have abundant minnows/shinners and fingerlings. Most every pond around me cannot keep minnows in them due to lack of weed beds, even though they have rip rap concrete along the sides and water lilies.
Eelgrass spreads pretty slowly but not as fast of many of the other pond weeds/filamentous algae types.
A Michigan State University Fisheries dept professor likes eelgrass for sportfish pond/lakes; he said fish can hunt thru it. It does not get to be a tangled mass like so many other pond weeds.
Larry, if I lived farther south like you I would seriously try to plant some of the corkscrew eel grass. It stays shorter and may not ever be a pest at all. It could provide a living rug 8-10" high all across the bottom of your pond and not allow many other weed types to get started or grow. You can always plant the longer "wild" type later if you see a need.
If you plant it, don't expect it to grow fast at all, it spreads slowly. I'd guess about 2-6 ft each year. If you want it to be all around your pond you'll have to plant it in numerous spots along the perimeter. B. Cody - Pond Doctor

Bill,
Thanks very much for the info. I believe that I will go ahead and get the eelgrass from the river. Basically because of availability and economics (translated: easy to get and free ). I especially like the prospect of having some minnows in my pond again. I like to watch them swim around.
I will probably only plant the shelf that I described. Then if the eelgrass ever becomes a problem, I will stock some amur. Although from your information, I really don't think that there will be any problems.

Thanks again,
Larry

Larry - No problems with the eelgrass at least for the first 4-8 years depending on the bottom composition. Keep an eye on the depth distribution. Once it gets too thick(?) start with only a few amurs; you can always add extra as needed. Allow them in the pond for at least 2 yrs before adding more. They need to get some size (20-28") before really doing a good job mowing eelgrass. IMPORTANT: don't get too many amur in the pond they CAN EASILY eliminate the eelgrass. You are better off getting a Y shaped lake-weed cutter and thinning the eelgrass yourself to help the amur keep it under control.

Bill,
I planted about a hundred or so eelgrass plants and now I'm going to have to get rid of a muskrat. He is eating them before they can get started.

I guess if the eelgrass ever gets to be a problem that I could always let the muskrats eat it. :rolleyes:

Larry