Texas Lake Weeds: Mechanical Control 

Every weapon for fighting exotic vegetative pests, has a down side. Biological weapons are difficult to control and predict future problems. Chemicals have an environmental downside, but less than most people think. Oddly enough, the most environmentally problematic is neither of the above, it introduces neither chemicals nor biological agents into the system, it is mechanical harvesting.

Mechanical harvesting is a problem because most of the invasive aquatic pests are proficient at vegetative reproduction. If a plant is removed, but the root is left behind, most will re grow readily from the root. They will also grow easily from broken and cut off remnants of plant material, some at a rate of 50% or more. If the plant is broken into pieces, and a hundred pieces are left behind, 50 or more will probably start reproduction!Rather than removing the problem, it has now become a much larger problem.

I have talked with several people who realized this just a little too late. Where they once had a problem over about 10% of the area, it is now covering 60 to 90 percent! That is when my phone starts ringing!

There is a place for mechanical removal, when used against the right type of alien invader, the results are excellent. When the infestation has gone unnoticed for too long, and the only thing that can be done is remove the problem each time it recurs. There are some other valid uses as well.

In dealing with aquatic problems, very often the chemical option is the best of all possible worlds.