Fish Toxicity of Commercial Herbicides Formulated With Glyphosate

On glyphosate

“…In fact, herbicidal activity of glyphosate on bean seedlings was partly attributed to parasitization of plants by soilborne fungi (Johal and Rahe, 1984;Johal and Rahe, 1988;Johal and Huber, 2009). This suggestion was confirmed in later investigations by Schafer et al (2012 and2013), who concluded that rhizosphere interactions play a major role in the phytotoxic action of glyphosate and might be involved in the evolution of weed tolerance and resistance to glyphosate in the field. A practical application of the phenomenon of synergistic phytotoxic action between pathogens and glyphosate was invented by Sharon et al (1992): they increased the weed controlling ability of the Alternaria crassicae-based mycoherbicide by adding very low (non-phytotoxic) concentrations of glyphosate.…”

“…At the same time residues of glyphosate and its primary metabolite aminomethylphosphonic acid (AMPA, Figure 5) were detected in the soil, in freshwater, and in the organisms that live there (Perez et al, 2011), in the crop products, in the animals that were fed with them, and in humans, too. Therefore, studies were initiated to determine whether continuous exposure to glyphosate leads to unwanted effects to the environment, such as soil microorganisms (Kremer and Means, 2009), insects (Saska et al, 2016), fish (Giannini, 2013), and to humans. Results of these studies were presented in a number of papers (Szekacs and Darvas, 2012;Myers et al, 2016;Mensah et al, 2015) and discussed in excellent books (to mention one: Nandula, 2010).…”

Acute toxicity effect of glyphosate on survival rate of common carp, Cyprinus carpio

“…It also reduced the survival rate of fish as non-target organism and had harmful effects on fish, which was also similar to the results of the present study. Jofré et al (12) studied toxicity of two commercial glyphosate on survival rate of two fish species (Danio rerio and Poecilia reticulata). The results of their study indicated that both herbicides may produce potential environmental damages, which is similar to the results of the present study.…”

“…EPSP is found only in plants and some bacteria (11). Glyphosate is highly soluble in water (10500 mL.L -1 ) and its half-life, depending on the environmental conditions, is between 3.5 and 70 days (12). However, Souza et al (13) pointed out that the half-life of glyphosate in freshwater was between 28 and 87 days.…”

Re-registration Challenges of Glyphosate in the European Union

“…A recent concern is that glyphosate (along with other herbicide active ingredients dicamba and 2,4-D), as well as common surfactants (Tween80, carboxymethyl cellulose) at or below recommended application concentrations can change the susceptibility of bacteria to a diverse range of antibiotics (ampicillin, chloramphenicol, ciprofloxacin, kanamycin, tetracycline) upon concurrent exposure, and thus, glyphosate may serve as one of the drivers for antibiotic resistance (Kurenbach et al, 2017;Van Bruggen et al, 2018). As indicated, through water pollution its formulations can disturb aquatic ecosystems (Vera et al, 2010;Perez et al, 2011) including fish (Jofré et al, 2013). Removal or degradation of glyphosate residues from raw drinking water by bank filtration may not be efficient, but oxidants used in water treatment (e.g., Cl 2 or O 3 ) were shown to be effective in degrading their concentration below the EU drinking water threshold level of 0.1 µg/l (Jönsson et al, 2013).…”