Acute Toxicity Effect of Haloxyfop-R-Methyl on 4 Marine Organisms

Abstract

Haloxyfop-R-methyl (HPME) is a selective herbicide for gramineous plants and has a removal effect on the coastal invasive organism Spartina alterniflora. In order to assess the risks of HPME on marine organisms in the governance process of Spartina alterniflora, this paper used the static-test method to evaluate the acute toxicity of HPME on four marine organisms. The results showed that four test organisms all showed muscle relaxation, decreased exercise capacity, and slow response under HPME exposure. As the test time prolonged, the mortality rate gradually increased, indicating that HPME had neurotoxicity and cumulative toxic effect on marine organisms. The 96 h median lethal concentration (LC50) of HPME for Mactra veneriformis、Apostichopus japonicus larvae、Cynoglossus semilaevis fry and Assiminea. lutea were were 0.888 mg/L, 1.382 mg/L、0.656 mg/L and 8.674 mg/L, respectively. The safe concentrations (SC) were 0.088 8 mg/L, 0.138 2 mg/L, 0.065 6 mg/L and 0.867 4 mg/L. According to the environmental safety assessment test guidelines for chemical pesticides, HPME was highly toxic to Cynoglossus semilaevis fry and Mactra veneriformis, and was moderately toxic to Apostichopus japonicus larvae and Assiminea. lutea. The results provided a reference for HPME in the elimination of Spartina alterniflora.

Keywords

• haloxyfop-r-methyl
• marine organism
• toxicity effect
• environmental safety