Environmental Science and Pollution Research

, Volume 26, Issue 30, pp 31077–31085 | Cite as

Toxicity of the aquatic herbicide, reward®, to the northwestern salamander

  • Michael L. MoretonEmail author
  • Vicki L. Marlatt
Research Article


Diquat dibromide (DB) is the active ingredient in several herbicide products used around the world for industrial and recreational control of terrestrial and aquatic pest plants. This study aimed to assess the adverse effects of the commercial formulation of the aquatic herbicide, Reward®, on the Pacific Northwest amphibian species, the northwestern salamander (Ambystoma gracile). Larvae were exposed to the Reward® herbicide in a 96-h acute bioassay (0.37–151.7 mg/L DB) and a continuous 21-day exposure (0.37–94.7 mg/L DB). The 96-h LC50 was 71.5 mg/L and the 21-day LC50 was 1.56 mg/L. Collectively, the results of this study demonstrate that early life stage A. gracile larvae appear largely insensitive to acute Reward® exposures compared to early life stage fish. However, A. gracile larvae are considerably more sensitive during sub-chronic exposure (21 days) with lethal and sub-lethal effects on growth occurring in the 1–2 mg/L range, which more closely resembles the larval fish lethal sensitivity to this active ingredient. This is the first study examining the toxicity of the aquatic herbicide formulation Reward® on A. gracile under acute and sub-chronic exposure scenarios.


Toxicology Aquatic herbicide Ecology Diquat dibromide Northwestern salamander Amphibians 



We are grateful to Dr. Chris Kennedy and Dr. David Huebert for their input on this manuscript.

Funding information

This work was funded by the National Contaminants Advisory Committee under the Department of Fisheries and Oceans Canada.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. Agriculture and Agri-Food Canada (2016) Pesticides Indicator. Accessed 03 January 2019
  2. Charles AL, Markich SJ, Stauber JL, De Filippis LF (2002) The effect of water hardness on the toxicity of uranium to a tropical freshwater alga Chlorella sp. Aquat Toxicol 60:61–73. CrossRefGoogle Scholar
  3. Cooke AS (1977) Effects of field applications of the herbicides Diquat and Dichlobenil on amphibians. Environ Pollut 12:43–50. CrossRefGoogle Scholar
  4. Dial NA, Dial CAB (1987) Lethal effects of diquat and paraquat on developing frog embryos and 15-day-old tadpoles,Rana Pipiens. Bull Environ Contam Toxicol 38:1006–1011. CrossRefGoogle Scholar
  5. Eagleson GW (1976) A comparison of the life histories and growth patterns of populations of the salamander Ambystoma Gracile (Baird) from permanent low-altitude and Montane Lakes. Can J Zool 54:2098–2111. CrossRefGoogle Scholar
  6. Egea-Serrano A, Relyea RA, Tejedo T, Torralva M (2012) Understanding of the impact of chemicals on amphibians: a meta-analytic review. Ecol Evol 2:1382–1397. CrossRefGoogle Scholar
  7. Emmett K (2002) Final risk assessment fsor diquat bromide The Water Quality Program. Accessed 03 January 2019
  8. Environment and Climate Change Canada (2008) ARCHIVED - Environment and Climate Change Canada - Acts and Regulations - Draft: State of the Science Report on the Bioaccumulation and Transformation of Decabromodiphenyl Ether. Accessed 03 January 2019
  9. Environment Canada (2007) Guidance Document on Statistical Methods for Environmental Toxicity Tests. Environmental Protection Series, Ottawa, Canada. Accessed 03 January 2019
  10. European Commission (2001) Directorate-General Health and Consumer Protection: Diquat. Accessed 03 January 2019
  11. Fent K, Weston A, Caminada D (2006) Ecotoxicology of human pharmaceuticals. Aquat Toxicol 76:122–159. CrossRefGoogle Scholar
  12. Folmar LC, Sanders HO, Julin AM (1979) Toxicity of the herbicide glyphosate and several of its formulations to fish and aquatic invertebrates. Arch Environ Contam Toxicol 8:269–278. CrossRefGoogle Scholar
  13. Government of British Columbia (2017) Species Factsheets, Northwestern Salamander. Accessed 03 January 2019
  14. Government of Canada (2017) Pesticides and pest management: for the public. Accessed 03 January 2019
  15. Grube A, Donaldson D, Kiely T, Wu L (2006) Pesticide Industry Sales and Usage Report: 2006 and 2007 Market Estimates. Accessed 03 January 2019
  16. Guderyahn LB, Smithers AP, Mims MC (2016) Assessing habitat requirements of pond-breeding amphibians in a highly urbanized landscape: implications for management. Urban Ecosyst 19:1801–1821. CrossRefGoogle Scholar
  17. Harrison R (1969) Harrison Stage and Description of Normal Development of the Spotted Salamander, Ambystoma Punctatum. Yale University Press, New HavenGoogle Scholar
  18. Herkovits J, Cardellini P, Pavanati C, Perez-Coll CS (1997) Susceptibility of early life stages of Xenopus Laevis to cadmium. Environ Toxicol Chem 16:312–316. CrossRefGoogle Scholar
  19. Hoffman RL, Larson GL, Samora B (2004) Responses of ambystoma gracile to the removal of introduced nonnative fish from a mountain lake. J Herpetol 38:578–585. CrossRefGoogle Scholar
  20. Horne MT, Dunson WA (1995) Effects of low PH, metals, and water hardness on larval amphibians. Arch Environ Contam Toxicol 29:500–505. CrossRefGoogle Scholar
  21. Howe CM, Berrill M, Pauli BD, Helbing CC, Werry K, Veldhoen N (2004) Toxicity of glyphosate-based pesticides to four North American frog species. Environ Toxicol Chem 23:1928–1938CrossRefGoogle Scholar
  22. International Union for Conservation of Nature (2015) Amphibian Specialist Group: Ambystoma Gracile.” International Union for Conservation of Nature - IUCN. Accessed 03 January 2019
  23. Kerby JL, Richards-Hrdlicka KL, Storfer A, Skelly DK (2010) An examination of amphibian sensitivity to environmental contaminants: are amphibians poor canaries? Ecol Lett 13:60–67. CrossRefGoogle Scholar
  24. Langeland KA, Warner JP (1986) Persistence of diquat, endothall, and fluridone in ponds. J Aquat Plant Manag 24:43–46Google Scholar
  25. Licht LE, Sever DM (1991) Cloacal anatomy of metamorphosed and neotenic salamanders. Can J Zool 69:2230–2233. CrossRefGoogle Scholar
  26. Mackay D, Alena K, Celsie D, Powell DE, Parnis JM (2018) Bioconcentration, bioaccumulation, biomagnification and trophic magnification: a modelling perspective. Environ Sci Process Impacts 20:72–85. CrossRefGoogle Scholar
  27. McCuaig L (2018) Hepatic proteome and toxic response of early-life stage rainbow trout (Oncorhynchus mykiss) to the aquatic herbicide, Reward®. Dissertation. Simon Fraser UniversityGoogle Scholar
  28. Moreton ML (2018) Effects of the aquatic herbicide, Reward®, on the Fathead Minnow and Northwestern Salamander. Dissertation. Simon Fraser UniversityGoogle Scholar
  29. Morrison C, Hero J (2003) Geographic variation in life-history characteristics of amphibians: a review. J Anim Ecol 72:270–279. CrossRefGoogle Scholar
  30. National Contaminants Advisory Group (NCAG) (2018) NCAG Projects: 2017-2020. Accessed 03 January 2019
  31. Organisation for Economic Cooperation and Development (OECD) (2009) Test No. 231: Amphibian Metamorphosis Assay. OECD Guidelines for the Testing of Chemicals, Section 2. OECD.
  32. Paul EA, Simonin HA, Symula J, Bauer RW (1994) The toxicity ofdDiquat, endothall, and fluridone to the early life stages of fish. J Freshw Ecol 9:229–239. CrossRefGoogle Scholar
  33. Perschbacher PW, Wurts WA (1999) Effects of calcium and magnesium hardness on acute copper toxicity to juvenile channel catfish, Ictalurus punctatus. Aquaculture 172:275–280. CrossRefGoogle Scholar
  34. Relyea RA, Jones DK (2009) The toxicity of roundup original Max® to 13 species of larval amphibians. Environ Toxicol 28:2004. CrossRefGoogle Scholar
  35. Ritter AM, Shaw JL, Williams M, Travis KZ (2000) Characterizing aquatic ecological risks from pesticides using a diquat dibromide case study. I. Probabilistic Exposure Estimates. Environ Toxicol Chem 19:749–759. CrossRefGoogle Scholar
  36. Simsiman GV, Chesters G (1976) Persistence of diquat in the aquatic environment. Water Res 10:105–112. CrossRefGoogle Scholar
  37. Smith-Gill SJ, Berven KA (1979) Predicting amphibian metamorphosis. Am Nat 113:563–585. CrossRefGoogle Scholar
  38. Solomon KR, Dalhoff K, Volz D, Van Der Kraak G (2013) Effects of herbicides on fish. In: Tierney et al. (ed) Organic chemical toxicology of fishes. Elsevier, pp 369–409Google Scholar
  39. Syngenta (2003) Environmental Stewardship, FAQ: Reward® Landscape and Aquatic Herbicide. Accessed May 2016
  40. Syngenta (2016) “Reward® Aquatic Herbicide Safely Data Sheet.”
  41. Syngenta Canada (2015) Reward® Label. Accessed 03 January 2019
  42. United States Environmental Protection Agency (1995) Reregistration Eligibility Decision. Accessed 03 January 2019
  43. United States Geological Survey (1975) Water Hardness.
  44. Yeo RR (1967) Dissipation of diquat and paraquat, and effects on aquatic weeds and fish. Weeds 15:42–46. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Biological SciencesSimon Fraser UniversityBurnabyCanada

Personalised recommendations