Every year, baleen whales– like blue, humpback, and fin whales– make long journeys from the cold polar seas, where they eat a lot, to warm tropical waters to breed. In the cold, they pack on fat for energy. But once they reach the breeding areas, they stop eating and live off those fat stores. As their bodies burn that fat, they produce waste, mainly in the form of urine. “That’s why they’re releasing nitrogen,” says Roman.
This makes whales important carriers of nutrients. The study found that through their waste– urine, carcasses, and placentas– baleen whales release around 3,784 tons of nitrogen and over 46,000 tons of organic matter into parts of the ocean that don’t have much of it. Most of the nitrogen comes from their pee. Just one fin whale can release up to 250 gallons of urine in a single day.