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Sublethal Exposure to Crude Oil Enhances Positive Phototaxis in the Calanoid Copepod Calanus finmarchicus

Abstract

We investigated the effects of exposure to sublethal concentrations of the water accommodated fraction (WAF) of fresh crude oil on phototactic behavior of the calanoid copepod Calanus finmarchicus (Gunnerus) copepodite stage 5 (C5). Exposure was conducted in closed bottle systems, and behavior was tested in a tailored setup. Exposure times were 24, 48, 72, and 96 h, and the chosen exposure concentration was 25% of the recorded LC50 value for the WAF (309 ± 32 μg/L total hydrocarbon, including 20.37 ± 0.51 μg/L total PAH). The exposure significantly increased the positive phototactic behavior of the copepods after 24 h exposure and a similar significant effect was observed for all exposure durations. Additionally, experiments were conducted with nonexposed copepods with low lipid reserves. The main effect of the exposure was a shift in the response to light toward a more positive phototaxis, similar to that observed in nonexposed C. finmarchicus with low lipid reserves. The observed change in phototactic behavior observed in these studies suggests that the depth distribution of this species could be altered following an oil spill. Thus, further research is warranted to determine the possible interactive effects of light and oil spill exposures on Calanus population dynamics under field conditions.

Category

Academic article

Language

English

Author(s)

  • Cecilie Miljeteig
  • Anders Johny Olsen
  • Trond Nordtug
  • Dag Altin
  • Bjørn Munro Jenssen

Affiliation

  • Norwegian University of Science and Technology
  • SINTEF Ocean / Miljø og nye ressurser
  • Diverse norske bedrifter og organisasjoner

Year

2013

Published in

Environmental Science and Technology

ISSN

0013-936X

Volume

47

Issue

24

Page(s)

14426 - 14433

View this publication at Cristin