Why do PCBs remain a threat to Atlantic marine life?

Polychlorinated biphenyls (PCBs) remain a persistent threat to marine life in the Atlantic Ocean primarily due to their extreme resistance to chemical decomposition and environmental breakdown.12

Because PCBs are highly stable, they persist in the marine environment for decades. Their threat is compounded by two key biological processes:32

• Bioaccumulation: PCBs are fat-soluble, causing them to accumulate in the fatty tissues of marine organisms.13
• Biomagnification: As smaller organisms are consumed by predators, the concentration of these toxins increases at each successive trophic level of the food chain.13

Even though the introduction of new PCBs into the environment has decreased, their long-term stability means they remain present in the water and sediment. They are particularly toxic to fishes and invertebrates, and trace levels have been detected even in deep-sea organisms. Protecting marine ecosystems from such persistent pollutants is an essential ethical responsibility to ensure the health and survival of ocean biodiversity.123