Akutte og forsinkede effekter af dimethoat pulseksponering på Hyalella azteca i forskellige aldersklasser

Thomas Beyer

Studenteropgave: Speciale


The purpose of the study was to test the effects a short pulse exposure of organophosphate with a high concentration could have a non-target organism and see whether the exposure had any delayed effects on reproduction, survival, pairing or impact on the time to first reproduction. For this the pesticide dimethoate chosen because of its general use as a pesticide in the EU and the U.S. and the amphipod H. azteca which habitat are still exposed to dimethoate. H. azteca in three age groups 8, 21 and 34 days old was selected for the acute toxicity tests with the concentrations; 0, 300, 600, 1200, 2400, 4800 and 10000 ug / L. The results of the acute toxicity test was an LC50 from 5642.92 to 9563.4μg / L and an EC50 from 2068.51 to 3296.66 μg /L after 48 hours exposure to dimethoate. The long-term effects of dimethoate was also observed and three age groups 8, 22 and 31 days of H. azteca were exposed to an integrated concentration of 2400 μg/L for one hour , and 100 μg/L over 24 hours. The experiment showed effects on reproduction and survival. After one hour of exposure to dimethoate a significant difference (p = 0.003) was observed in age group 22 days in the reproduction when compared to the control and exposure concentration 100 μg/L.

UddannelserMiljøbiologi, (Bachelor/kandidatuddannelse) Kandidat
Udgivelsesdato30 mar. 2014
VejledereAnnemette Palmqvist


  • H. Azteca
  • pulseksponering
  • dimethaot