Altered developmental timing in early life stages of Antarctic krill (Euphausia superba) exposed to p,p '-DDE

• Published in: Science of The Total Environment
• Main Authors: Poulsen, Anita H., Kawaguchi, So, Leppanen, Matti T., Kukkonen, Jussi V. K., Bengtson Nash, Susan M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2011
• Subjects: Persistent organic pollutant (POP); Antarctic krill; Early life stage (ELS) testing; Tissue residue approach (TRA); 2304 Environmental Chemistry; 2305 Environmental Engineering; 2310 Pollution; 2311 Waste Management and Disposal; Antarctic; Southern Ocean; The Antarctic; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: https://espace.library.uq.edu.au/view/UQ:264229

Persistent organic pollutants (POPs) are persistent, toxic and bioaccumulative anthropogenic organic chemicals, capable of undergoing long range environmental transport to remote areas including the Antarctic. p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) has been identified as a dominant POP accumulating in Antarctic krill (Euphausia superba), which is a key Southern Ocean species. This study examined the developmental toxicity of p,p'-DDE via aqueous exposure to Antarctic krill larvae. p,p'-DDE exposure was found to stimulate developmental timing in the first three larval stages of Antarctic krill, while extended monitoring of larvae after a five day exposure period had ended, revealed delayed inhibitory responses during development to the fourth larval stage. Stimulatory responses were observed from the lowest p,p'-DDE body residue tested of 10.1 ± 3.0. μmol/kg (3.2 ± 0.95 mg/kg) preserved wet weight, which is comparable to findings for temperate species and an order of magnitude lower than the exposure level found to cause sublethal behavioural effects in Antarctic krill. The delayed responses included increased mortality, which had doubled in the highest p,p'-DDE treatment (95 ± 8.9% mortality at 20. μg/L p,p'-DDE) compared to the solvent control (44 ± 11% mortality) 2 weeks after end of exposure. Development of surviving metanauplius larvae to calyptopis 1 larvae was delayed by 2 days in p,p'-DDE exposed larvae compared with untreated larvae. Finally, the developmental success of surviving p,p'-DDE exposed larvae was reduced by 50 to 75% compared to the solvent control (100% developmental success). The lowest observed effect concentration for all delayed effects was 1. μg/L, the lowest exposure concentration tested. These findings demonstrate the importance of delayed and indirect effects of toxicant exposure. Further, the findings of this study are important for environmental risk assessment of POPs in the Southern Ocean ecosystem and strongly highlight the significance of developmental endpoints for ecotoxicological testing.