Oil droplet ingestion and oil fouling in the copepod Calanus finmarchicus exposed to mechanically and chemically dispersed crude oil

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Nordtug, Trond, Olsen, Anders J., Salaberria, Iurgi, Øverjordet, Ida B., Altin, Dag, Størdal, Ingvild F., Hansen, Bjørn Henrik
• Other Authors: Statoil, Shell, BP, ENI Norge AS
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Calanus finmarchicus; Copepods
• Online Access: http://dx.doi.org/10.1002/etc.3007; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fetc.3007; https://onlinelibrary.wiley.com/doi/pdf/10.1002/etc.3007; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/etc.3007; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.3007

Abstract The rates of ingestion of oil microdroplets and oil fouling were investigated in the zooplankton filter‐feeder Calanus finmarchicus (Gunnerus, 1770) at 3 concentrations of oil dispersions ranging from 0.25 mg/L to 5.6 mg/L. To compare responses to mechanically and chemically dispersed oil, the copepods were exposed to comparable dispersions of micron‐sized oil droplets made with and without the use of a chemical dispersant (similar oil droplet size range and oil concentrations) together with a constant supply of microalgae for a period of 4 d. The filtration rates as well as accumulation of oil droplets decreased with increasing exposure concentration. Thus the estimated total amount of oil associated with the copepod biomass for the 2 lowest exposures in the range 11 mL/kg to 17 mL/kg was significantly higher than the approximately 6 mL/kg found in the highest exposure. For the 2 lowest concentrations the filtration rates were significantly higher in the presence of chemical dispersant. Furthermore, a significant increase in the amount of accumulated oil in the presence of dispersant was observed in the low exposure group. Environ Toxicol Chem 2015;34:1899–1906. © 2015 SETAC