The Whale Pump: Why is Poop so Important for the Planet?

Whales of all shapes and sizes play a significant role in the health of marine ecosystems. About 50% of the air humans breathe is produced by the ocean, thanks to phytoplankton and whale waste. The “Whale Poop Loop” is the foundation of the marine food web and the planet’s lungs.

Packed with nutrients, whale waste (poops) is a super fertiliser that supports phytoplankton, which produces oxygen and is food for zooplankton, fish, and other marine species. The marine creature phytoplankton support then provide food for shorebirds and humans. These marine leviathans also help mitigate the human-made climate crisis. One whale can capture an average of 33 tons of carbon dioxide over its lifespan. While, a live oak tree, one of the most efficient carbon-capturing tree species, captures about 12 tons of carbon dioxide over a up to 500 year lifespan.

The whale pump, or “poop loop,” refers to the exchange of nutrients and movement of carbon through our global ocean, driven by whale excrement. To understand this vital ecological process, we must understand our players:

First, we meet phytoplankton. The colourful world of phytoplankton encompasses a host of bacteria, algae, and certain single-celled organisms capable of converting sunlight into food–a process we all know as photosynthesis. These sun-loving little organisms reside near the ocean’s surface and possess the extraordinary ability to capture extensive amounts of global carbon each year, helping to maintain climate balance. Over millions of years, they’ve also added staggering amounts of oxygen to the Earth’s atmosphere– supporting wildlife and people around the globe.

Then, there’s the zooplankton. This classification consists of larger but still mostly microscopic marine organisms like sea snails, worms, and krill. Most frequently, they feast on phytoplankton– absorbing their carbon and storing it in their small but mighty bodies! Each day, zooplankton embark on the world’s largest migration. During the day, they dive into deep waters, and at night, they return to the surface.

Finally, we meet the great whale. This group includes all baleen whales (including humpback whales, blue whales, fin whales, gray whales) and the sperm whale. Their massive size awards them this famed moniker, and this immensity in mass can only be rivalled by the enormity of their impact.

Whales help breathe life into our planet and keep our ocean’s food web functioning with their poop. Each day, baleen whales dive deep in the water column and eat massive amounts of krill – 5-30% of the whale’s body weight per day, in fact!

The whale then travels back to the surface and introduces deep ocean nutrients through their excrement to the photic zone (the top layer of the ocean). When they relieve themselves, they add nitrogen, phosphorus, and other trace metals, like iron, to the water column. We call these nutrients ‘limiting nutrients,’ meaning that organisms require these nutrients for photosynthesis and other critical biological processes. Their finite availability determines if these processes can take place. Without the presence of whales, these essential ingredients for life are much scarcer, and phytoplankton populations dwindle. Given their migratory nature, whales help boost populations of photosynthetic phytoplankton throughout the entire ocean! These increased populations provide immense support for their zooplankton predators and, in turn, the whales who feast on the zooplankton – rounding out the full whale pump loop!

With their support to phytoplankton, the benefits ripple beyond these three groups of animals. So many more marine species rely on phytoplankton and zooplankton as a food source, and our ocean’s whales support them all!

Team Maverick