Whiz, Poop, Rot: How Whale Waste Helps Oceans Thrive

Whales leave behind all kinds of organic matter—poop, pee, skin, placenta and more—with big benefits for marine ecosystems

By Jennifer S. Holland
Wildlife Science
Dec 17, 2025

IN MAY 2025, a 53-foot-long sperm whale killed by a boat strike washed up on shore near Seaside, Oregon. Typically, such a behemoth rotting in a public place is removed. But this time, local authorities decided to let the animal play its final part in the circle of life by serving as nourishment for wildlife scavengers, from gulls to bears.

Both on the beach and at sea, “waste” is a misnomer when it comes to whales. As scientists pick through the chemical slurry migrating whales leave behind in the ocean during long journeys, they’re discovering that the foulest packages can house the most life-nourishing gifts. It’s a process they’ve dubbed the “great whale conveyor belt.”

As baleen whales, such as humpbacks and blues, filter feed through keratin plates hanging from their upper jaws, they transport biomass and nutrients thousands of miles between their feeding and breeding areas. Then, in what scientists call a whale pump, the animals cycle between feeding in deep waters and breathing at the surface, emitting nutrient-rich bodily bits, fluids and other treats along the way. The nutrients support a diversity of animals, drive phytoplankton blooms and boost carbon storage. How are these beneficial products packaged and delivered?

• Tinkle-down effect. Urine may seem like the end of the line, but whale pee has proven surprisingly full of useful stuff, especially nitrogen. Because whales need to expel excess nitrogen and phosphorus, especially mothers-to-be after summer feasting, they pee regularly and plenty—some as much as 250 gallons per day. At the base of the food web, microbes and phytoplankton incorporate this transported nitrogen into their cells for growth and sustenance, fueling the broader ecosystem. Whale pee is a true boon for the masses, says conservation biologist Joe Roman of the University of Vermont, who reported in Nature Communications that humpbacks, for instance, “bring more nitrogen across thousands of miles from places like Alaska to Hawai‘i than local physical forces like wind and upwelling.”

• The skin they’re in. Whales regularly slough dead skin along with parasites called cyamids, or whale lice, that nibble on their hosts. Both zooplankton and fish, such as lumpfish and topsmelt, gobble up these protein- and fat-rich offerings. In the Canadian Arctic, researchers observed bowhead whales rubbing against large rocks in the shallows to exfoliate and stimulate new skin growth. Orcas have been seen using kelp like a loofah sponge, likely for the same purpose. Remnants from those trips to the sea spa feed other animals, including birds from above and fish from below.

• Poo-poo platters. Recent studies have looked at how chemical ingredients in whale poop may affect the health of oceans—with some notable surprises. Because whales feed in deep water (sometimes below 2,500 feet) and poop at the surface, the animals create what amounts to an upwelling of nutrients though their feces. Poop, like urine, is full of nitrogen. But also, to researchers’ amazement, it includes “a s--- ton of iron,” says oceanographer Patrick Monreal of the University of Washington. As iron is crucial for living things, Monreal decided to study whether whales, during the process of digestion, may convert otherwise toxic iron into a form that other creatures can use.

It turns out they do, and in a big way. Filter-feeding whales gorge on vast schools of tiny crustaceans called krill—sometimes 30,000 cheeseburgers worth of calories a day. When released in poop, the iron formerly contained in living krill “is once again ‘bioavailable’ and is used by phytoplankton for photosynthesis and by other microbes for respiration,” Monreal says.

In particular, the Southern Ocean relies on pooping whales’ contribution, because it lacks the natural sources of iron found, say, near the Atlantic (dust from the Sahara, for example). Without whales, “we’d be missing a crucial nutrient recycling process, with important downstream effects on the ecosystem,” he says.

Monreal and his colleagues, who reported their findings in Communications Earth & Environment, also were surprised to discover that whale poop is packed with copper, which is needed by some microbes but potentially deadly to other living things. The scientists found that whales’ guts detoxify copper before releasing it in their feces.

“Both the iron and copper findings were unknown and blew us away,” Monreal says. Although other krill eaters, such as penguins and seals, also transform prey into nutrients, he adds, the unique gut microbiomes and very long digestive tracts of baleen whales seem to do it more efficiently. In addition, they offer the important benefit of copper detoxification.

• The afterbirth. Whale calves give back to the oceans at various stages: The placenta that nourished them in utero, once passed by the mother, is a nutritious buffet for fish. It can weigh more than 200 pounds and is plump with edibles. A calf’s poop, too, contains multitudes, as does a stillborn calf or a juvenile that doesn’t survive. Because infant mortality can be 20 percent or more among whales, these dead are substantial donors to other hungry critters.

• Whale fall. As its grand finale, a dead whale, young or old, can become a temporary biodiversity hot spot. Known as whale fall, a whale carcass sunk to the seabed draws thousands of scavengers of hundreds of species, from sleeper sharks to octopus to crabs to worms. The pulse of activity continues as snails and bristle worms gorge on muscle and blubber, and ends as bacteria and bone-eating worms with specialized enzymes break down and consume the rest. These worms, along with many shrimp, mussels and other animals, can spend their entire adult lives on a single carcass. Across generations, their descendants may use whale falls as stepping stones between hydrothermal vents and other deep-sea habitats.

As one last contribution, whales store significant amounts of carbon in their bodies—an average of 33 tons per animal over a lifetime. When they die, they take that carbon with them to the seafloor, preventing its release to the atmosphere as climate-warming carbon dioxide. A single individual may store the carbon contained in its body for hundreds or thousands of years—a whale of a gift to planet Earth.

Read about writer Jennifer S. Holland.