[Cod from Vestlandsfjorder analysed for chlorine insecticides and PCB]

Area of Science:

• Environmental Chemistry
• Marine Biology
• Toxicology

Context:

• Norwegian fjords are vital marine ecosystems.
• Cod (Gadus morhua) are a key species in these fjords.
• Persistent organic pollutants (POPs) are a global environmental concern.

Purpose:

• To quantify chlorinated insecticide and Polychlorinated Biphenyl (PCB) levels in Norwegian cod liver.
• To identify potential sources of contamination in fjords.
• To assess the environmental impact of DDT and PCBs on marine life.

Summary:

• Gas liquid chromatography analysis of cod liver from 21 Norwegian fjord locations revealed universal presence of DDT, DDE, DDD, and PCBs.
• Mean DDT residue levels varied from 0.2 to 25 ppm, and PCB levels ranged from 0.3 to 3.9 ppm (wet weight).
• Elevated DDT concentrations correlated with proximity to fruit orchards, suggesting agricultural runoff as a significant source, while current forest nursery DDT use showed minimal fjord contamination.

Impact:

• Provides crucial data on POPs contamination in a commercially important fish species.
• Highlights the localized impact of agricultural practices on marine environments.
• Informs environmental monitoring and regulatory strategies for POPs in coastal ecosystems.