Guest Author - Alegra Bartzat

Herbicides are commonly used by individuals, businesses, and the government as part of what has become normal lawn and garden care procedure. Herbicides are chemicals that kill or stunt the growth of plants, usually what we refer to as weeds. Herbicides can be synthetics (manufactured in a laboratory by humans), or they can be natural (usually derived from other plants and concentrated). While both types pose acute risks with concentrated exposure, it’s the synthetic herbicides that pose a greater risk, as they do not break down in the environment after they are applied. While organically derived herbicides decompose in a relatively short amount of time, synthetic herbicides leach into the ground after they are applied to lawns and gardens. Here they can move through communities, affecting other plants, animals, the water supply, eventually even humans.

Atrazine is a common herbicide used in lawns, cornfields, and in very high doses on golf courses throughout the country. In homes, atrazine is sprayed either by hand-held devices, where the sprayer carries the tank of herbicide on his back. Commercially, atrazine can be applied by a car that covers the ground (like a golf course), or even by plane, spraying everything in its path, such as over a cornfield. Only a small percentage of the hundreds of thousands of gallons of atrazine sprayed on plants each year reached the weeds that are targeted. The majority of the herbicide falls on other plants, which may or may not be affected, depending on the morphology and biology of the plant. After it reaches the plant, the herbicide will be absorbed by the soil, and will eventually find its way to nearby streams, then rivers, and eventually the ocean.

Marine scientists Maria del Carmen Alvarez and Lee Fuiman at the University of Texas at Austin study the effects of atrazine on red drum, a very popular ocean game fish. While they have not noticed major effects on adult red drum, what they have observed are effects on red drum larvae. The red drum, and many other coastal fish, lay their eggs in estuaries (such as wetlands or swamps), because the estuaries offer protection to the developing fish. The estuaries also serve as collecting points for run-off, the very same water that is carrying the atrazine downstream (along with a bundle of other herbicides, pesticides, and automobile pollution). The red drum larvae grow slower and become hyperactive when exposed to atrazine. The hyperactivity leads them to be detected by prey, such as jellyfish, and the slow grow means that fewer larvae make into the juvenile stage, and therefore never become reproducing adults. This is bad news for coastal ecosystems, as well as sport fisherman.

As you can see, atrazine is a factor in declining population of red drum. Herbicides can be directly linked to negative affects on marine life. Herbicides kill more than the weeds they are aiming to kill off. Is the price we are paying for a weed-free lawn worth it? Is grass really that great? Are weeds really that bad? After all, as the great thinker Ralph Waldo Emerson said, “What is a weed? A plant whose virtues have not yet been discovered.”