Dietary exposure of Antarctic krill to p,p'-DDE: uptake kinetics and toxicological sensitivity in a key polar species.
This study evaluated the dietary uptake kinetics and sublethal toxicity of p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) in Antarctic krill. The uptake rate constant (characterised by the seawater volume stripped of contaminant sorbed to algae) of 200 ± 0.32 mL g(-1) wet weight h(-1), average absorption efficiency of 86 ± 13% and very low elimination rate constant of 5 × 10(-6) ± 0.0031 h(-1) demonstrate the importance of feeding for p,p'-DDE bioaccumulation in Antarctic krill. Faecal egestion of unabsorbed p,p'-DDE of 8.1 ± 2.7% indicates that this pathway contributes considerably to p,p'-DDE sinking fluxes. A median internal effective concentration (IEC50) of 15 mmol/kg lipid weight for complete immobility indicates baseline toxicity and that Antarctic krill exhibit comparable toxicological sensitivity as temperate species under similar 10 d exposure conditions. These findings support the critical body residue approach and provide insight to the role of Antarctic krill in the biogeochemical cycling of p,p'-DDE in the Southern Ocean.
The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 39 Kessels Rd, Brisbane, QLD 4108, Australia. ahpoulsen@ucdavis.edu
Anita H
AH
Poulsen
Peter F
PF
Landrum
So
S
Kawaguchi
Susan M
SM
Bengtson Nash
D000818:Animals; D000864:Antarctic Regions; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D004032:Diet / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D033201:Euphausiacea / Q000187:drug effects / Q000378:metabolism*; D007306:Insecticides / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D007700:Kinetics; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*
D007306:Insecticides; D014874:Water Pollutants, Chemical; D003633:Dichlorodiphenyl Dichloroethylene