What’s behind all the glyphosate hysteria, and why should it worry anglers?
[by Ted Williams]
“CANCER WARNING, Roundup [glyphosate]” shouts a typical ad, one of hundreds on TV and social media. “You may be entitled to financial compensation. Call Knightline Legal…”
No herbicide has been used more, studied longer or been proven safer than glyphosate. And no herbicide is more essential for saving aquatic and terrestrial ecosystems from invasive plants.
Despite popular and incorrect nomenclature, native aquatic plants (which disgust ecologically challenged swimmers) are rarely “weeds.” Most serve fish and other aquatic organisms the way native trees and understory serve terrestrial life, recycling nutrients, slowing sediment transport and producing oxygen, cover and food.
Glyphosate formulations labeled for aquatic use include Rodeo, ShoreKlear, Pondmaster, Toughdown Pro, AquaPro, AquaNeat and Avocet. No herbicide may be so labeled if it has more than one in a million chance of harming humans, fish or any nontarget organism.
LD50 stands for the lethal dose that kills half the test animals per unit of mass. Higher is safer. For rats, caffeine’s LD50 is 192, glyphosate’s 5,600.
Still, local glyphosate bans are proliferating, and pressure is mounting for a national ban. There’s a dirty, disturbing story behind the public panic. But first, a review of how glyphosate saves fish.
Nowhere is glyphosate more desperately needed than in the alien hell that is Florida.
In June 2011 biologist Don Fox of the Florida Fish and Wildlife Conservation Commission toured me by airboat around Lake Okeechobee, the heart, lungs, and kidneys of the Everglades. What happens here affects life all the way to and in Florida Bay.
Fish, alligators, and turtles swirled from our path. Ospreys hovered, snail kites wheeled, and a manatee that had negotiated the entire St. Lucie Canal sashayed over a shallow bar. A wide, half-mile-long swath of brown, withered cattails marked the area Fox had sprayed with glyphosate. Cattails are native, but the huge slug of phosphorus from dairy farms and ag land renders them invasive.
“They’re good guys gone bad,” Fox told me in May 2019. “If we didn’t use glyphosate, cattails would crowd out native vegetation, and organic sediments would build up, causing anaerobic conditions. We’d lose our invertebrate communities, and that would magnify up to forage fishes and game fishes.”
Glyphosate is an especially effective tool for combatting giant salvinia infesting bodies of water throughout the South. Few, if any, aquatic weeds are more deadly to fish than this free-floating, duckweedlike fern. “It just explodes,” says Dr. Wes Neal of Mississippi State University’s Extension Service. “If not sprayed, it takes over, shading out sunlight, depleting oxygen, and killing fish.”
Without glyphosate, non-natives such as water hyacinth and torpedo grass would proliferate from Florida to Texas. They’d create huge mats that would smother such natives as bulrush and knotgrass—spawning, nursery, and foraging habitat for catfish, bass, crappies, bluegills, and redear sunfish.
Phragmites, an alien grass, blights America’s three coasts. It pushes out native wetland plants, killing fish, birds, mammals, reptiles, amphibians, and the complex food webs that sustain them. Two-thirds of all sport and commercial fish depend on coastal wetlands at some point in their lives.
Phragmites destroys inland wetlands too. In Utah, for example, it has devastated populations of the federally endangered June sucker and eliminated spawning and nursery habitat of largemouth and smallmouth bass, pike, and panfish. What’s more, it blocks angler access.
In most cases you can’t pull or plow phragmites, because the roots are so deep. The only alternative is herbicide, usually glyphosate.
Aaron Eagar, Utah’s noxious weed program manager, offers this: “Utah Lake has 7,000 acres of phragmites around its shoreline. In the 1950s it wasn’t there. For the last seven years, we’ve treated it with Rodeo [glyphosate], and we’ve brought back lots of natives and opened up areas for fish and fishing. Phragmites grows out to four feet in water and all the way to the transitional zone of dry land. We get rid of the biomass by burning or cutting; then we spray new growth.”
But, provided it’s green, what takes over aquatic and terrestrial ecosystems doesn’t much matter to the public, media, or even a large element of the environmental community. Human health, not fish and wildlife, is their main issue. They seem to imagine that glyphosate, safest of all herbicides, is the reincarnation of Agent Orange. Part of that fear is misplaced aggression.
Environmentalists hate Monsanto, glyphosate’s major distributor, because it sells neonicotinoids that wipe out pollinators. And it has genetically engineered “Roundup Ready” crops unaffected by glyphosate, so farmers can blitz ag land without hunting down weeds.
This from Dr. Lee Van Wychen, who directs science policy for the National and Regional Weed Science Societies: “Farmers overused glyphosate. It was too good to be true. You could spray it anytime. It was extra safe for the environment, and it killed almost any weed. The selection pressure they put on that herbicide was unparalleled in the history of weed control. When you apply the same herbicide on 200 million acres multiple times a year, a few weeds are gonna get lucky and then pass on their resistance.”
These “super weeds” require harsher herbicides such as dicamba, which can drift long distances. In 2018 dicamba killed crops on hundreds of non-targeted Midwest farms.
So awash is North American ag land with glyphosate that traces (far below federal safety standards and measured in parts per billion) are turning up in wine, beer, and cereal.
In March 2015 the International Agency for Research on Cancer (IARC), a semiautonomous body loosely tied to the World Health Organization, placed glyphosate on its “2A List” of substances with “limited or inadequate evidence of carcinogenicity” or, in IARC’s abbreviated translation, “probably carcinogenic.” Right up there with glyphosate on IARC’s 2A list of probable carcinogens is “red meat” and “very hot beverages.”