Harvesting vs. Chemical Treatment
Harvesting vs. Chemical Treatment
The current problems at the lake were largely magnified this year because of excessive weed growth. The public was concerned and the Borough of Hopatcong was able to secure funding to chemically treat the weeds in the area of the State Park. Because the weed harvesters were basically disabled this was probably the only solution for the residents in that part of the lake. However we think the public needs a better understanding of the problems created by using chemicals to treat the weeds.
First, understand that whether the weeds are mechanically harvested or chemically treated, that is only treating the symptom of a much greater problem. It is much like wiping your nose when you have a cold. You will have some immediate relief for a short while, but it's going to be a continuing problem until you get rid of the cold. The real problem at the lake is an excessive load of nutrients, such as phosphorus and nitrogen, entering the system. This occurs because of septics, storm water runoff and decaying weeds.
Chemical treatment will usually have an immediate effect on the weeds but can also create much greater problems. First, the weeds that die, drop to the bottom and decay, creating more nutrients that will act as fertilizer for the next year's weed growth. Blanket treatment destroys fish habitat where the young of the year need to hide from the predators. Defoliating large areas will reduce fish populations long term. Continued treatment can result in toxic conditions in the sediment making future dredging either too expensive or impossible. The chemicals do not biodegrade but stay in the system forever.
Mechanical harvesting has problems also. It is slow and costly and subject to equipment failures like this year. But, scientifically it is a much better option. By physically removing the weeds from the lake you reduce the nutrients that feed the weeds. Remove 'X' tons of weeds and you reduce the nutrient load by 'Y'. It actually slows down the lake aging process. It can also be done in methods like cross cutting, that actually enhances fish habitat. But remember that both of these solutions are only treating the symptoms and we need to solve the root cause, which is, inadequate waste water and storm water management.