Many contaminants are lipophilic, meaning that they dissolve in fats (lipids). Porpoises have blubber, a thick layer of fat underneath the skin that keeps them warm. And that is where contaminants accumulate over time and get stored. Porpoises have a very high metabolic rate, meaning that they need to eat constantly. They can be described as the “hummingbirds of the sea”, relying on a constant intake of nutrients, night and day. If they do not eat for even a short time, they use their fat reserves and the contaminants stored in their blubber get mobilized into their systems.

Some contaminants are believed to affect the immune system of porpoises; they may also have effects on their ability to reproduce.

References and Further Reading
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