According to research from the Australian Antarctic Division, whale poop is about 10 million times more concentrated with iron than sea water. Here's why:

Iron is found in algae (phytoplankton) on surface waters

Krill eat the algae

Whales eat the krill

The iron eventually ends up back at the surface in the form of whale poop

The algae use this iron for growth

This is a simplified version of what actually happens, but you get the idea. It’s a self-sustaining system with a very high level of production. Algae serves as the base for the aquatic food chain, so the more whale poop there is, the more abundant the ocean will be.