One of Earth's unsung heroes is also among its tiniest. Plankton, a single-celled algae, is barely visible to the eye, but it contributes to some of the world's most important resources. It's essential to the food chain, it's a main supplier of oxygen and it's the fuel that keeps our cars running and our homes heated.
These organisms, no bigger than a human hair, float in the sunny, upper parts of the ocean. The two main types of plankton — phytoplankton and zooplankton — actually support one another. Phytoplankton, an organism so small that millions can fit in one drop of water, produces its own energy through photosynthesis. It accounts for nearly half of all photosynthesis on the planet. Zooplankton (small animals and crustaceans like copepods) and other small fish and marine creatures eat phytoplankton, then become food for bigger fish, and so on up the food chain.
From seals to dolphins, virtually every creature in the ocean eats either plankton or an organism that depends on plankton. In a David-versus-Goliath-like battle, filter-feeding baleen whales like the humpback rely on tiny organisms such as plankton and krill. Like a filter, these whales take in huge gulps of water, then use their tongues to push out liquid so food like krill and plankton remain. Right whales also swim open-mouthed through plankton-filled waters; they trap the plankton, and their tongue pushes the organism down their throat.
But plankton's role in the food chain doesn't stop in the ocean. Polar bears and sea birds rely on plankton-fueled meals like seals and fish. Even humans count on fish (and therefore plankton) to survive. Americans alone eat around 15.5 pounds (7 kilograms) of fish and shellfish per person, per year. Now that's a whole lot of plankton.
Plankton is even making its way to our dinner tables. English chefs like Angel Leon and Nuno Mendes of Michelin-starred Aponiente added plankton to their Taste of the Sea menu in 2013. This includes delicacies like a plankton cocktail, plankton risotto and plankton rice with aioli. They went this route for health reasons — plankton has many antioxidant properties, Leon told Metro — but became enamored with the "elegant" taste along the way.
"It's velvety and dry before mixing it with liquid. Silky once mixed, oily and elegant, pungent on the nose yet subtle and leaves a long finish in the mouth," Leon said.
While it's still rare in restaurants, plankton is slowly catching on. According to Fine Dining Lovers, plankton-producers like Spanish agriculture company Fitoplankton Marino are growing the microalgae for human consumption, and one chef even tried his hand at phytoplankton bread.