Turbidity

How you proceed with this project, will depend on what you are starting with, and with what your goals are. In either case many of the same procedures apply. If you are starting with a newly built pond It may be necessary to get some vegetation growing along the banks. This will be needed to lower the turbidity of the water. Turbidity is simply the soil particles that are held in suspension in the water. If you have a lot of clay, and a lot of rain, the water will probably be muddy. Covering the banks with vegetation, will lower the number of soil particles that end up mixed with water, by helping to prevent erosion.

If turbidity is a problem, almost everything you need to do to will be effected. That is why we bring it up first. We will cover the best ways of dealing with suspended sediments in the next section.

Turbidity problems are sometimes found in older ponds as well. This usually results from runoff of soil containing water from disturbed ground. Plowed fields, and construction sites are sometimes responsible. Increased vegetation around the pond should help with this as well.

Eutrophycation

A common problem in older ponds is eutrophycation. Eutrophycation is excessive fertility. This often occurs when nutrient rich runoff from over fertilized lawns and pastures ends up in your pond. Here, again, vegetation should provide the solution. A thick vegetative barrier can be planted at the mouth of the pond.

These things will need to be done before proceeding to the next part of the project.

On the surface, biological controls for aquatic lake weeds seems like a great idea. It sometimes is. Biological control seems to be the “green” thing to do, but I have a few things that cause me to question this method.

Biological Lake Weed Controls

• The controls are limited. There are a few weevils, that eat a couple of plants, there is an oriental fish that eats almost any vegetation, but so far, that’s about it.
• Although all sanctioned biological controls have been thoroughly researched by the top scientists in the field, things can still go wrong. Changing weather conditions, and interaction with other species over extended periods of time could bring about a completely unexpected chain of events, culminating with a new ecological disaster!
• If the new control is a natural enemy of the exotic plant we are trying to stop, and something changes, you now have two invasive predators in the environment instead of just one. What if the new entity decides it likes to eat sweet potatoes, corn, or soybeans more than what it was brought in to control?
• While the only legal grass carp in the state of Texas, are sterile, accidents can still happen. The accidental, or even intentional introduction of a pair of non sterile fish into our waters could spawn the cleanest, but deadest fishing lakes in the world. The escape of the sterile form into a river could do immense damage as well.

I have other concerns as well, but in a completely controlled setting, the desired effect could be gained, but we should exercise extreme caution when using this method.

Physical Mechanical Lake Weed Controls

One of the methods for controlling lake weeds being used today, is physical control. The cutting, harvesting, pulling, or rolling down of the weeds by mechanical means. Mechanical, or physical control is useful in several situations. Physical removal is not always a good thing. Many times, mechanical means fragmentation which can lead to problems.

Aquatic vegetative reproduction.

Exotic weeds, and even some native plants often reproduce vegetatively. This is just another way of saying that pieces of the plant can, and do develop roots, or feeding tentacles when broken away from the mother plant. This is especially true of aquatic plants.
Many lake and pond weeds reproduce from fragments at a rate of 50% or higher. Imagine this: If you have 1 hydrilla plant in your lake, and you chop it up into 100 pieces, the chances are very high, that you will have 50 of the fragments survive and take root. Multiply that by 1000, and you can begin to understand the problem!
Now, the use of mechanical controls can be good, and sometimes are the only means of bringing about a pond or lake that is clean enough for recreational use, but it should be avoided if possible.

Aquatic weed mechanical control guidelines.

We have developed a few guidelines based on our observations.

• If the lake weed problem is in the early stage, there is hope for eradicating it. Try using the chemical method early, and often until the problem is gone.
• Continue to use the chemical treatments for periodic maintenance, and make adjustments to the environment such as liming if needed, and fertilization. If aquatic weeds can’t get sunlight, they can’t grow. Proper fertility will help to keep the proper level of suspended algae growth.
• If mechanical lake weed control is needed, it should be done with the least disturbance to the plant possible, to limit fragmentation. The plants should be cut smoothly.
• The fragments should be harvested from the water. Every fragment is a potential plant, so remove them all.

Next: Chemical Controls

Lake weed prevention is the best form of control

It will be too late to bring this up for some private pond and lake owners, but for others, this information should prove beneficial.

The very best method for controlling lake and pond weeds, especially those of non native origin such as Hydrilla, Water Hyacinth, Giant Salvinia, and many others, is to prevent them from getting a start in your pond or lake.

Methods of Trans-location

There may be some methods of trans-location which are beyond your control, such as water coming onto your property from other bodies of water upstream, or movement of animal life such as ducks, geese, cranes, and herons who could be carrying hitch hikers, but the highest percentage of exotic aquatic trans-location occurs through human help.

This can be intentional, such as planting some of those nice little blue flowers someone saw at another lake, or adding a little hydrilla for good bass cover. This is never a good idea. In the first place it is illegal, and in the second, those cute little flowers, or that nice cover for bass, could soon engulf your lake!

It can be unintentional, such as not cleaning your boat, prop, trailer, live well, and other fishing gear after a trip to an infested lake. It is best to consider all lakes as though they are infested, and clean accordingly! While some public lakes do not have these problems, it is still a good idea to do a thorough cleaning before moving to the next location. You should also require anyone else boating or fishing on your private impound to do the same. These methods will not guarantee a lake free of exotic invaders, but they will help you to do all that is in your power to prevent them.