A little lake weed control pop quiz!

I hope you paid attention in class!

Lake weed control problems occur as a result of?

• A. The invasion of exotic lake weeds.

• B. Excessive fertility in ponds and lakes.

• C. Lack of plankton to color the water.

• D. Too much light penetrating to the lake bed.

If you answered “D”, you answered correctly. Congratulations! We could have added fifth, for “all of the above”, but it really would not matter. The all inclusive fact is, that without the light penetration to the bottom of a lake, weeds will not grow. No matter how fertile the water, no matter how little algae bloom, no matter what type of lake weed, native or exotic, it can not grow without light!

Water color and depth

Light penetration is determined by two things. The waters color, and depth. If the water is “dark” enough, light can not reach the bottom where weeds, and even algae get their start. If the water is deep enough, light can not reach the bottom. Both issues should be dealt with. There are always areas that will be shallow, and your fish need the food provided by the chain that starts with algae bloom, but some light can penetrate even perfectly colored water and reach the bottom in very shallow areas.

Algae bloom

It is true that algae bloom can go a long way toward decreasing that light, and thereby decreasing the growth of lake weeds, but it can not stop all of them. In shallow areas on sunny days, and in the summers when lakes lose water to evaporation, weeds may exist high enough in the water profile, to get light, and grow faster than the water is replaced. Fluctuating depth can give the weeds a start when the water is low, and then allow them to continue to grow as the water gradually rises.

Water depth

There is really only one way to prevent this problem. Make the lake deeper! This can be done by raising the water level, as in raising the height of the drain outlet or spillway, but that can put your lake at risk. We have all seen water soaked dams fall victim to erosion.

Dredging

There is another way. Dredging. Getting rid of the years of silt that are deposited in the bottom of your lake can decrease your lake weed problems. Most people know that this is an expensive, and messy exercise, but weighing it against constant chemical lake weed control treatment costs for several years may make it look a lot more appealing in the long run. Besides that, new technology is producing new types of equipment that may make it a less costly, and less messy proposition.

You might want to give dredging some consideration during these early days of the “off” season. Getting the dredging done during the late fall and early winter should have you back to normal for the spring and summer fishing fun.

That is your lake weed control test for the day. Class dismissed!

Note:

Chemical controls can be highly effective for dealing with aquatic lake weeds, but will only kill the growth present at the time. If the cause of the underlying problem is not dealt with, the weeds will return. You can count on it. Lake owners should be aware that lake maintenance like any other property maintenance is an ongoing proposition.

In fishing ponds and lakes, irrigation reservoirs, and stock tanks, pond scum algae can be a serious problem. It can cause water intakes to fail, cause mosquito problems, and cause fishing to be a swampy, messy, less than fun experience. So, how do you get rid of it.

Pond scum can be removed manualy by skimming it from the top, but scum skimming is not much fun, and can be quite time consuming.

There are a lot of products on the market for getting rid of pond scum algae. Copper products, both granular, and liquid can be spread or sprayed across the top of the algae, causing it to die and sink. Diquat also works well. Whichever product you choose, follow the label directions to a “T”. To do otherwise is a violation of federal law, and can do severe damage to your pond or lake.

If the body of water is completely covered, do not treat more than from one quarter, to one third of it at a time. Dying vegetation uses up dissolved oxygen, and if too much is depleted, it can kill your fish. Proper chemicals, properly applied, will not usually kill fish, but dying vegetation will.

Pond scum, it goes by a lot of different names, but most of the time, it is really a type of algae known as filamentous algae.

Algae, are very primitive plants, there are several types, including the planktonic algae that is often suspended in the water profile of a pond or lake, and gives it that green tint that we are all familiar with. It is a single cell, that feeds aquatic invertebrates, which, in turn, feed larger creatures and so on up the food chain.

There are more advanced forms of algae as well, such as “Nittela”, and “Chara”, which resemble vascular rooted plants.

Filamentous algae, or pond scum starts growing at the bottom of a body of water, and gradually moves to the top by virtue of the buoyancy it provides through the creation of oxygen by the process of photosynthesis.

Pond scum, algae

If you want to raise a lot of catfish in a small pond, provided that it is relatively clean and all other criteria are met, you can do so simply by regular feedings. You don’t have to have good algae bloom to do this. At least that’s the line I hear often from the experts. It is true, you can. I say you can, but you shouldn’t!

You can get a lot better result from periodic fertilization, and the addition of a few fathead minnows. Why fertilize in this situation? Well, it is really pretty simple. If you fertilize, you can get the algae bloom to feed the microscopic and somewhat larger creatures which will become food for the minnows, which will become food for the catfish. This will keep the life cycle going, and provide a little supplement to your “supplemental” feedings.

It also provides cooling and oxygen in the water, which will serve to increase the health and size of your fish. The cooling and oxygen production is reason enough! There are other benefits as well. It will keep your fish from acting like lazy teenagers lying around all day. It will improve taste and texture, and it is just better!

Besides, the cost is minimal, the labor is light, and the outcome is a better pond, with better fish!