Effects of Acclimation in Risk Asessment - Acclimation Effects of Fluoranthene on Hydrobis sp.

Beata Joanna Lehka, Henrik Wennermark & Lykke Vils Axelsen

Studenteropgave: Semesterprojekt


The consequence of an exposure to a sublethal level of contaminant may result in development of resistance to higher concentrations. The hydrophobic compound fluoranthene is a common PAH that can be found in the sediment in aquatic environments. The gastropod Hydrobia sp. is an abundant deposit feeder in muddy shallow waters that lives and feeds on the surface of sediment were it can be exposed to fluoranthene. Occurrence of acclimation by Hydrobia sp. to fluoranthene was tested by EC50 after an acclimation period of 28 days. The acclimation concentrations were a control (0 μg Flu/g dry weight sediment), low (1μg Flu/g dry weight sediment) and high (30 μg Flu/g dry weight sediment). LC50 for Hydrobia sp after 10 days of exposure had a value above 180 μg Flu/g dry weight sediment. With the EC50 it was tested how feeding rate in terms of pellets production, moving rate and behavior (sediment avoidance) was influenced by the exposure to fluoranthene. Fluoranthene exposure causes narcotic effect and hormesis in Hydrobia sp. in the first two lower concentrations in the EC50. The results showed that the Hydrobia neglecta and Hydrobia ulvae can acclimate to concentrations of 1μg Flu/g dry weight sediment (low) but not to 30 μg Flu/g dry weight sediment (high) for 28 days of exposure. The acclimation high was too high for the snails as a start concentration to acclimate. The acclimation to low concentrations can lead to resistance to higher concentrations. This shows that when working with organisms taken from nature in laboratory experiments the acclimatization and acclimation to compounds present in the environment should be taken into consideration.

UddannelserMiljøbiologi, (Bachelor/kandidatuddannelse) Bachelor el. kandidat
Udgivelsesdato27 jan. 2009
VejledereAnnemette Palmqvist


  • Experimental method
  • Hydrobia sp
  • Fluoranthene
  • Acclimation