The stunning power of whale pee

In the deep blue water, a one-month-old humpback whale nuzzles up to its mother. Then, a cloud of dark yellow urine gushes into the water, like a golden smoke bomb, and everything becomes tinged with green. 

This footage provides a new clue to an important ingredient for a healthy ocean: whale wee.  

Scientists have spent a lot of time thinking about how the nutrients in whale feces—also known as whale pump—benefit species in shallow waters, as whales swim up from the deep sea, where they feed, to poop near the surface.

But they had overlooked another important nutrient source: urine.

Now, a study published in Nature Communications corrects the knowledge gap. It finds that whale urine is an essential part of a thriving marine ecosystem.

(Why these orcas are wearing salmon as hats—again)

“The big surprise of the study is that urine far outweighs the other sources of nitrogen,” like carcasses, for example, says co-lead author Joe Roman, PhD, a conservation biologist at the University of Vermont. Plus, whales don’t tend to produce nutrient-rich poop during breeding season, but they do still urinate.  

Essentially, baleen whales transport nitrogen and phosphorous from their polar feeding grounds to tropical breeding spots where those elements are lacking—and without those critical nutrients, marine plants and animals wouldn’t survive.

Whales pee when they migrate, spreading nutrients around the world

The study analyzed the nutrients baleen whales — whose members include gray, blue, humpback, and fin whales —  add to the ocean through their urine, carcasses, and placentas. All these sources unleash 3,784 tons of nitrogen and 46,512 tons of organic matter to low-nutrient areas. And urine accounts for most of the nitrogen. (A single fin whale alone can produce 250 gallons of urine in a day.)

In summer, whales bulk up by feeding in nutrient-rich polar regions. Then they migrate to mate and reproduce in warm tropical waters, which are typically low in nutrients. During the winter breeding season, they rely on the energy reserves stored in their blubber and muscles; the process of breaking these down to release energy creates water and waste products, which become urine.

“That’s why they’re excreting this nitrogen,” he says.

These enormous mammals also release energy and nutrients into the environment through placentas—which are a few hundred pounds each, according to Roman—and carcasses. And, all told, these whale excrements move significantly more nutrients than natural physical processes like weather events. “In a place like Hawaii, the whales are bringing in more nitrogen than is being transported by wind and currents,” Roman says.

Whale pee is good for the sea

Whale urine contains high levels of nitrogen and phosphorus, which all living organisms need to survive.

 “These nutrients stimulate phytoplankton growth at the ocean surface and also enrich deep sea ecosystems,” says Heidi Pearson, PhD, professor of marine biology at the University of Alaska Southeast, who was not involved in the study.

By bringing these elements to ecosystems that lack them, these weeing whales keep the whole ocean ship-shape. 

Why conservation is essential to ocean health

The researchers estimate that these figures would have been around three times higher before commercial whaling nearly wiped out some species before it was banned in 1986 (although Japan, Norway, and Iceland still hunt them). 

“Some whale populations have still not recovered from industrial whaling and most whales are imperiled by a myriad of threats including vessel strikes, fisheries entanglement, pollution, and climate change,” says Pearson.

Without whales, the rest of the ocean is in trouble too.

(Maybe megalodon wasn’t so chonky after all)

“The ocean is spluttering along like an old car with rusty parts that aren't functioning properly,” says Ed Goodall, head of intergovernmental engagement at Whale and Dolphin Conservation, which partly funded the study. “We've removed vital processes delivered by whales that help keep the ocean functioning like a well-oiled machine.”

If we want a resilient and healthy marine ecosystem, we must protect whales, adds Pearson: “The ocean would be a very different place without whale poo or urine.”