I agree with your assessment of this situation. I have held (5) categories of State certifications in pesticide application including aquatic application, and have sprayed thousands of gallons of these compounds over the years. I see the continued use of these chemicals as a predictable failure, and would support litigation to end the practice as soon as possible. While they may be effective in spot clean up of small areas they cannot eradicate this weed by this method. While the physical removal aspects of this project certainly capture a lot of nutrients that are tied up in the Ludwegia, it is clear to me that dredging would do a better job and is an absolute requirement for restoration. This experiment is an unfortunate but predictable failure and needs to be turned around. Perhaps that will require the threat of litigation, and some mediation. Ongoing pesticide and herbicide spraying is like putting makeup on a pimple. It is cosmetic, but does not cure the infection. Spraying is not capable of eliminating the weed, or the root (pun intended) causes of the problem.
It is clear that the chemical being used Glysosate in minute concentrations damages the survival and interferes with the migration patterns of endangered species of salmon by blocking their olfactory senses. We allowed the public health concerns over the West Nile mosquito vector to drive the expenditure of more than a million dollars on this project, without confronting the primary issues responsible for the problem. It is clear to anyone who has spent time analyzing the problem that only a TMDL controlling nutrients and sediment, coupled with dredging sediment laden with these nutrients, will achieve lasting success. Dredging would also improve ground water recharge and flood control objectives.
If the excuse for continuing this band aid spraying approach, is the control of the West Nile threat, allow me to say that there are biological ways to control the mosquito issue which do not require insecticide or pesticide. One of the easiest methods of accomplishing this objective is covered under one of my US patents. The control strategy involves floating solar powered White Knight microbial generators in the impacted areas, while continuing the harvest strategy for those areas which are not under water. The White Knight microbial generator can be charged with a time release packet containing: bacillus therengensis, bacillus subtilus, bacillus lichenoformis, and pseudomonas fluorescens. These microbes are non-pathogenic and designed to be time released into the water column. The bacillus therengensis acts as a stomach poison to mosquito larvae. I have used the other facultative aerobic bacteria assemblage successfully in the Laguna under Fish and Game, and RWQCB oversight, following an apple waste spill that occurred near highway 12 in Sebastopol. The results were spectacular, resulting in odor free, clear and healthy water in the stretch between highway 12 and Occidental road throughout the duration of the project. The aerobic environment (microclimate) created around the White Knight device supports mosquito fish such as gambusia affinis, and other important aerobic creatures, which would otherwise be unable to survive under the current anoxic conditions, and fluctuating pH created by the Ludwegia canopy. This short term method of bioremediation is no substitute for dredging coupled with Nutrient TMDL’s but it is non-toxic, far more effective, and far less expensive in controlling mosquitoes (West Nile Boogey Man) than any method of chemical poisoning of the water. We know that applying any mixture of chemicals like glysosate as this failure demonstrates, is a boondoggle and amounts to a futile attempt to temporarily set back the log growth of an aquatic plant that has unlimited nutrients and ideal conditions at its disposal.