Pacific salmon, such as those discussed in the last slide, are not the only species that has been identified as capable of transporting pollutants to remote areas. Wania (1998) has used seabirds and whales to exemplify the ability of migratory animals in transporting persistent organic pollutants (POPs), many of which are endocrine disruptors, to the Arctic. In the case with seabirds, the annual amount of POPs (particularly PCBs and DDT) transferred in and out of the Arctic was estimated to be from grams to kilograms. For whales, the amount was estimated to be in the order of several tons. These estimates suggest that the amounts of some POPs transported by migratory animals, especially whales, may be in a similar order of magnitude as the gross rates estimated for atmospheric and oceanic transports.

In an earlier study by Comba et al. (1993), an effort was made to quantify the transport of the pesticide mirex from Lake Ontario to the St. Lawrence river system. The authors estimated that, for the time period 1950 to 1990, 290 kg of mirex were transferred downstream with water and sediments, and another 60 kg by migrating eels, thus suggesting that biotransport was of a similar order of magnitude as the transports in abiotic media. In still an earlier study, Lum et al. (1987) concluded that eels transferred more mirex out of Lake Ontario than what these creatures did to suspended particulate matter.

According to the United Nations Environment Programme (UNEP, 1998), each year a fair number of the migrating birds die in their winter quarters in the warmer southern regions. These birds thus are likely to leave a considerable amount of POPs in their winter quarters that their bodies have accumulated from their northern summer quarters prior to migration.