06
Mar
Nutrient Runoff, Aquatic Weed Killers, and Florida’s Red Tide Collide in Public Debate
(Beyond Pesticides, March 6, 2019) After a brief hiatus, Florida Fish and Wildlife Conservation Commission (FWC) is continuing use of aquatic herbicides, including glyphosate, for invasive species management. Public pressure and feedback caused FWC to take a temporary pause from spraying while the commission collected public comment through public hearings and emails from late January through February. FWC ultimately decided to resume spraying invasive species, and points to its improved integrated management system as reducing overall herbicide use.
Glyphosate, one of the 17 aquatic herbicides that FWC uses regularly has sparked opposition from environmentalists and the general public due to its wide usage and known adverse effects. According to FWC data, 12,263 pounds of glyphosate-based herbicides were used on Florida’s Lake Okeechobee in 2017.
About 175,000 people have signed North Palm Beach photographer and wildlife advocate Jim Abernathy’s petition titled “Stop The State-Sanctioned Poisoning of Our Lakes and Rivers!”. The petition decries the use of glyphosate to kill invasive aquatic plants and warns of subsequent nutrient pollution caused by decay. An excess of nutrients (e.g. nitrogen and phosphorus) in water bodies contribute to algal blooms. Eutrophication can eventually result in oxygen depletion and thereby decrease biodiversity. FWC denies that the invasive species management program contributes to either red tide (discoloration caused by an explosion of algae) or blue/green algae build up, citing lack of evidence and asserting that keeping low populations of the plant reduces buildup of decaying plant material.
Invasive aquatic plants, such as water hyacinth and hydrilla, plague Florida’s waterways. They displace native plant communities and disrupt recreation – particularly waterhyacinth, which can get so thick as to be impassable. Water hyacinth is a free-floating aquatic plant native to Amazon River in Brazil. Mature plants reproduce rapidly through horizontal stolons; populations can double in as little as 6-18 days. Mechanical means of management are difficult, as dense populations can weigh as much as 400 tons per acre. The plant then needs to be taken away from the waterway, and disposal can be expensive and time consuming. In response to the question, “Why can’t the FWC just use mechanical control and eliminate the use of herbicides?,” FWC noted:
“Research and tests conducted on Lake Okeechobee and other waterways throughout the state have consistently shown that mechanical harvesters alone are ineffective for large-scale control of these fast-growing exotics. In past tests, when harvesters replaced chemicals on Lake Okeechobee, the plants multiplied faster than they could be harvested, lake conditions became unsuitable for navigation and recreation, and there was a significant loss of native habitat. One crew applying herbicide can cover approximately 10 acres a day, whereas a crew operating a harvester can typically clear only .5 acre a day. Some biological controls can have moderate success on some types of plants but, despite many research efforts, we have not found a biological control agent that provides good results on floating plants such as water hyacinths.”
Those who use alternatives say that employing nonchemical strategies requires different approaches than chemical-intensive strategies. For example, timing of harvesting and the use of biological controls becomes an important factor in efficacy of these non-chemical approaches. Additionally, economists evaluating the cost of pesticide use in comparison with nonchemical approaches have evaluated secondary costs, such as those associated with adverse health effects, contamination, clean-up costs, weed resistance, and more. In most cases, chemical-intensive approaches are inherently more expensive.
Florida residents are concerned about the impact on people and wildlife of chemicals used, while FWC responds to this apprehension with the position that, “Herbicides registered for use in aquatic environments undergo years of rigorous evaluation with the U.S. Environmental Protection Agency (EPA).” Additionally, FWC states that it works with universities and research institutions for “environmentally compatible and cost-effective strategies to apply herbicides to control target vegetation while conserving or enhancing non-target plants and animals.” However, with industry-influenced research and a history of negligence regarding the potential harm associated with undisclosed pesticide product ingredients (inerts), independent critiques have found EPA’s pesticide evaluation process to be inadequate.
While not ending herbicide use entirely, FWC is “recommitting to employing methods that minimize the quantity of herbicides needed to achieve the desired level of control.” A news release from March 1, 2019 details their improvements as:
- Accelerating the development of habitat management plans for individual lakes.
- Forming a Technical Assistance Group consisting of staff, partners and stakeholders.
- Improving the timing of herbicide-based invasive aquatic plant treatments.
- Exploring ways to better integrate and increase the strategic use of mechanical aquatic plant harvesting.
- Exploring new methods and technologies to oversee and increase accountability of aquatic plant control contractors.
- Developing pilot projects to explore better integrated plant management tools.
- Improving agency communication regarding plant management activities.
FWC is still accepting comments through [email protected]. You can read Beyond Pesticides’ 2018 article “Meeting the ‘Invasive Species’ Challenge” or our “Least-toxic Control of Weeds” for more information about Beyond Pesticides’ approach to weed management.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources: Naples News, News-Press, Florida Fish and Wildlife Conservation Commission
So the same government department that is cleaning up and counting the dead marine life is pouring the poison in the lakes and rivers? Job security or tunnel vision? What a mess!
November 27th, 2019 at 11:35 pm