A new study published this week in Nature Communications shows whales carry out the longest known transport of nourishment by mammals on the planet, helping to sustain and grow marine life.
This incredible recycling of nutrients in the ocean is derived from deposits of whale urine, feces, placentas, carcasses and sloughing skin, which is generated in both their summer feeding habitats and winter breeding grounds as well as transported through the ocean as they migrate.
According to report author and whale expert Joe Roman:
“If plants and phytoplankton are the planet’s lungs, taking in carbon dioxide and expelling oxygen, then whales and other animals are like the circulatory system. Known as the great whale conveyer belt, this movement of nutrients through the ocean can have a big impact on marine ecosystems.”
The study, partly funded by marine charity Whale and Dolphin Conservation (WDC) with an international research team, highlights that this process of moving essential nutrients like nitrogen from high-latitude (polar) areas like Alaska and Antarctica to low-nutrient tropical grounds like Hawaii and the Caribbean is the longest known transport of nourishment by mammals on the planet.
WDC’s Head of Intergovernmental Engagement Ed Goodall said:
“The reduction in whale numbers by commercial whaling and multiple pressures that they suffer from today means the ocean has lost is delivery drivers, moving things from one place to another. By moving nutrients around the planet, just as bees pick up and move pollen, whales help keep the ocean functioning just like pollinators do on land. If we restore their numbers and the processes which they deliver, like the great whale conveyor belt, the ocean will be healthier, more abundant, and resilient in the face of a changing climate.”
Humpback, gray and right whales transport more than 3,700 tons of nitrogen each year. This is roughly equivalent to farmers spreading about 2 million bags of fertilizer on their crops. These whales bring more nitrogen from their feeding grounds than the ocean’s natural processes such as ocean currents and upwellings provide, significantly boosting marine life. This nutrient input helps fuel phytoplankton growth (tiny plants that absorb vast amounts of carbon and produce oxygen), which is critical for the marine food web.
In summer, pregnant North Pacific humpback whales gain about 14 kg (31 pounds) per day eating herring and krill, but they burn, or lose, almost 100 kg (220 pounds) per day while they are nursing on the breeding grounds. As they burn up their energy reserves, they release nitrogen and other elements in their urine.
Previous research in Iceland suggests that fin whales produce more than 250 gallons (about 974 liters) of urine per day when they are feeding, while humans pee about 2 liters per day (less than half a gallon).
Check out the full study.
