Skip to main content
Log in

Toxicity of the herbicide glyphosate and several of its formulations to fish and aquatic invertebrates

  • Published:
Archives of Environmental Contamination and Toxicology Aims and scope Submit manuscript


Studies were initiated to determine the acute toxicity of technical grade glyphosate (MON0573), the isopropylamine salt of glyphosate (MON0139), the formulated herbicide Roundup® (MON02139), and the Roundup® surfactant (MON0818) to four aquatic invertebrates and four fishes: daphnids (Daphnia magna), scuds (Gammarus pseudolimnaeus), midge larvae (Chironomous plumosus), mayfly nymphs (Ephemerella walkeri), Rainbow trout (Salmo gairdneri), fathead minnows (Pimephales promelas), channel catfish (Ictalurus punctatus), and bluegills (Lepomis macrochirus). Acute toxicities for Roundup ranged from 2.3 mg/L (96-h LC50, fathead minnow) to 43 mg/L (48-h EC50, mature scuds). Toxicities of the surfactant were similar to those of the Roundup formulation. Technical glyphosate was considerably less toxic than Roundup or the surfactant; for midge larvae, the 48-h EC50 was 55 mg/L and for rainbow trout, the 96-h LC50 was 140 mg/L. Roundup was more toxic to rainbow trout and bluegills at the higher test temperatures, and at pH 7.5 than at pH 6.5. Toxicity did not increase at pH 8.5 or 9.5. Eyed eggs were the least sensitive life stage, but toxicity increased markedly as the fish entered the sac fry and early swim-up stages. No changes in fecundity or gonadosomatic index were observed in adult rainbow trout treated with the isopropylamine salt or Roundup up to 2.0 mg/L. The aging of Roundup test solutions for seven days did not reduce toxicity to midge larvae, rainbow trout or bluegills. In avoidance studies, rainbow trout did not avoid concentrations of the isopropylamine salt up to 10.0 mg/L; mayfly nymphs avoided 10.0 mg/L of Roundup, but not 1.0 mg/L. In a simulated field application, midge larvae avoided 2.0 mg/L of Roundup. Application of Roundup, at recommended rates, along ditchbank areas of irrigation canals should not adversely affect resident populations of fish or invertebrates. However, spring applications in lentic situations, where dissolved oxygen levels are low or temperatures are elevated, could be hazardous to young-of-the-year-fishes.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others


  • Bartley, T. R.: Aquatic weed test station. Water Conservation Report No. WC-24, Bureau of Reclamation, U.S. Department of Interior, Washington, D.C. 32 pp (1965).

    Google Scholar 

  • Brauhn, J. D., and R. A. Schoettger: Acquisition and culture of research fish: Rainbow trout, fathead minnows, channel catfish and bluegills. Ecol. Res. Ser. EPA-660/3-75-011. U.S. Environ. Prot. Agency. Washington, D.C. 45 pp (1975).

    Google Scholar 

  • Comes, R. D., V. F. Bruns, and A. D. Kelly: Residue and persistence of glyphosate in irrigation waters. Weed Sci.24, 47 (1976).

    Google Scholar 

  • Committee on Methods for Toxicity Tests with Aquatic Organisms. Methods for acute toxicity tests with fish, macroinvertebrates and amphibians. Ecol. Res. Ser. EPA-660/3-75-009. U.S. Environ. Prot. Agency, Washington, D.C. 67 pp (1975).

    Google Scholar 

  • Folmar, L. C.: Overt avoidance reactions of rainbow trout fry to nine herbicides. Bull. Environ. Contam. Toxicol.15, 509 (1976).

    PubMed  Google Scholar 

  • : Avoidance chamber responses of mayfly nymphs exposed to eight herbicides. Bull. Environ. Contam. Toxicol.19, 312 (1978).

    PubMed  Google Scholar 

  • Hansen, D. J.: Avoidance of pesticides by untrained sheepshead minnows. Trans. Am. Fish. Soc.98, 426 (1969).

    Google Scholar 

  • Litchfield, J. T., Jr., and F. Wilcoxon: A simplified method of evaluating dose effect experiments. J. Pharmacol. Exp. Ther.96, 99 (1949).

    Google Scholar 

  • Marking, L. L.: Toxicological protocol for the development of pesticides. Pages 26–31 in P. H. Eschmeyer (ed.): Rehabilitation of fish populations with toxicants: A symposium. Am. Fish. Soc., North Central Div. Spec. Publ. 4 (1975).

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Folmar, L.C., Sanders, H.O. & Julin, A.M. Toxicity of the herbicide glyphosate and several of its formulations to fish and aquatic invertebrates. Arch. Environ. Contam. Toxicol. 8, 269–278 (1979).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: