This invention is in the field of the suppression of sub-surface aquatic weed growth. More specifically, this invention relates to a sub-surface aquatic weed barrier consisting of a strip of plastic, with a series of gas release ports, which is held down by transverse weights bonded to the plastic strip.
Some relative patents:
4056936November 1977Mayer405/302.74518280May 1985Fletcher405/174577996March 1986Elias, Fletcher405/17
The problem with weed infestation in relatively shallow (eight feet or less) bodies of water whether they be ponds, lakes, canals, irrigation ditches, or tidal areas has been increasingly obvious. (See: Michigan State University manual E-2437 issued 12/98 titled “Aquatic Pest Management” with particular reference to Chapter 6. Another relative article can be found at “www.Army.mil/el/aqua/apis/mechanical/eurasian.html). The condition is evident in almost any aquatic environment where there is relatively slow movement of the water. Aquatic weed growth has a deleterious effect on aquatic activities and can be a health hazard. If permitted unchecked the ultimate result of aquatic weed growth is the transformation of the body of water into swamp and eventually into great farm land. The relatively recent introduction of Eurasian Milfoil into the US Northeast's aquatic ecosystem has been a disaster. Some idea of the costs relating to the control of aquatic weeds can be gleaned from a report of the projects funded by the State of Washington under their Aquatic Weeds Program for the period 1994 to 2000 found at site: “www.ecy.gov/programs/wq/plants/grants/projects.html”
A review of the literature indicates that many solutions have been proffered:
1) Mostly they involve the repeated use of chemical agents. The EPA's interest in these chemical treatments has tended to limit their use and effectiveness and the repeated applications are costly.
2) Another proffered solution is the mechanical removal by cutting or pulling out the objectionable weeds. The required continuous application of such procedures, their labor intensive nature, and the problems with the disposal of the removed material have limited the use of these techniques.
3) Yet another solution is the lowering of the body of water in the Fall of the year and trusting in mother nature to kill the weeds and their seeds. This requires a significant lowering of the water level through a period of deep freezing and has proven to be only a slight mitigator of the problem in the next season. Also most affected bodies of water can not be lowered adequately or there is not the potential for deep freezing. And, the most serious objection to this solution, the surviving weeds are generally the naiads and the Eurasian Milfoil—the major problems.
4) Another proffered solution is the covering of the soil below the water with a shield of some sort to stop the sun's rays from stimulating weed growth. The trick here is to keep the cover, usually a plastic film or screen, down on the ground below the water while permitting the gases resulting from decomposition to escape.
5) Another solution is the introduction of grass eating fish. The down sides here include the fact that these particular fish prefer other weeds than Eurasian Milfoil and therefore remove the desirable weeds before attacking the problem weeds and the need to feed the fish after the weeds are eaten.
6) The solution theoretically most acceptable is the deepening of the water to the point where inadequate sunlight gets to the aquatic substrate to foster the growth of weeds or when weeds grow they do not reach the surface of the water. In most instances this is not a practical solution.
It therefore would be desirable to provide an aquatic weed suppressor which is economical, easy to install and not overly labor-intensive, long-lasting, will remain in place, and will effectively kill all types of targeted weeds.