Sierra Rayne of the University of Victoria and colleagues conducted earlier research on free-ranging orcas, also known as killer whales, and found evidence that they too retain pollutants.

维多利亚大学的希拉·雷恩和她的同事们早前对虎鲸，即逆戟鲸，进行了研究，证据显示虎鲸同样在体内存积污染物。