In addition to the ecological impacts on land, recently, the National Oceanic and Atmospheric Administration (NOAA), showed that atrazine negatively affects marine phytoplankton [3, 4]. These microscopic organisms serve as food for other organisms such as clams and oysters and the effect of atrazine is likely reflected throughout marine food webs: Phytoplankton serves as food for zooplankton which is in turn food for many larval and young fish and several species of whales. Thus, atrazine’s impact on this critical member of the marine foodweb will have dramatic and irreversible effects on marine life including damage to commercially important shellfish and finfish populations as well as sea mammals (whales) of which many are already threatened or endangered.
Figure 2. Phytoplankton. These microscopic organisms serves as food for zoolplankton which in turn serves as food for higher organisms, including clams, oysters, fish, and even some species of whales. Image from: http://www.noaanews.noaa.gov/stories2007/s2778.htm
Similarly, atrazine negatively affects freshwater aquatic habitats. Several studies have shown that atrazine decreases algae and other aquatic plant life [5-7]. This plant life serves as food for microorganisms and invertebrates that in turn serve as food for other organisms up the food web including fish. Further, algae, and other aquatic plants serve directly as food for larval frogs (tadpoles) and atrazine will negatively affect important sentinel species of amphibians, many of which are already declining, endangered, or threatened.
After 49 years of using atrazine at or above 80 million pounds per year, many target weed species have become atrazine-resistant [1, 2]. In fact, the number of documented atrazine-resistant “super” weeds number more than 80. No other herbicide has produced such dramatic effects on the evolution of weeds.
Figure 1. Common Groundsel (Senecio vulgaris), one of more than 80 atrazine-resistant "superweeds" that have evolved in response to atrazine use. Common groundsel is the most common weed in the world. It is poisonous and can cause permanent liver damage, resulting in death, if eaten. Image from: http://mint.ippc.orst.edu/groundsel.htm
Atrazine has detrimental ecological impacts on plants and wildlife