According to a new study, some Icelandic orcas have very high concentrations of polychlorinated biphenyls(PCBs) in their blubber but other orcas from the same population have levels of PCBs that are much lower and it’s mainly down to what they eat.
Orcas that eat a mixed diet of seals, or other marine mammals such as porpoises and fish (mainly herring) had concentrations of PCBs in their blubber that were up to nine times higher on average than the orcas that eat mainly fish. The findings unexpectedly contradict earlier research that had found relatively low levels of PCBs in most Icelandic orcas.
Photo Credit: Filipa Samarra – Icelandic Orca Project
