Turns out, whales do a whole lot more than just swim around looking majestic — they’re helping to keep our oceans healthy every time they excrete waste.

A new study published in The Biophysicist shows that the poop of baleen whales (humpback and blue whales) is packed with nutrients that ocean life needs to thrive. Whale feces are rich in iron, which tiny ocean plants called phytoplankton use to grow. These plants are the base of the marine food web.

So, more iron means more food for fish and essentially everyone else on the planet.

Whales are not just fertilizing the ocean, they’re also cleaning up potential toxins.

Whale poop has copper, but special compounds in it bind the copper tightly, stopping it from becoming toxic to marine life.

Prior to industrial whaling, which drastically reduced whale populations, oceans likely had a much better nutrient-recycling system. This new research suggests that these natural ecosystem engineers could help restore ocean health.

More like this: Polluted oceans: Let the trash take itself out