PCB Transport in the Food Chains (image) Aarhus University Share Print E-Mail Caption When foreign hazardous substances enter the marine environment, they are assimilated into the first link in the food chain, phytoplankton. The phytoplankton is consumed by zooplankton, which in turn is consumed by smaller fish, etc. The chemicals accumulate in each link of the food chain, and this means that killer whales that feed on large animals in contaminated areas may contain concentrations of PCBs so high that the survival of the species is threatened. Killer whales that primarily feed on smaller fish are not threatened in the same way. Credit Graphic: Aarhus University Usage Restrictions May be used in relation to this press release. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.