The Drifters
Plankton planet: Meet the creatures who make up 98 percent of the oceans’ biomass. /
Even when God makes a little thing, it is great because of the wisdom displayed in making it. The microscope has taught us the greatness of God in creating tiny creatures of wondrous beauty, yet so small as not to be perceptible to the naked eye. “The works of the Lord are great.”
—Charles Spurgeon, Exposition of Psalm 111
Take two breaths. For one of them, you can thank the plankton, in particular the single-celled photosynthetic drifters that compose the phytoplankton of the world ocean. Remarkably, these elegant, microscopic cells perform nearly half of the photosynthesis and consequent oxygen production on Earth—equivalent to the total amount of photosynthetic activity of land plants combined. These tiny single cells have transformed the ocean, atmosphere, and terrestrial environment and helped make the planet habitable for a broad spectrum of other organisms, including ourselves. In many cases, blooms of phytoplankton reach such densities that they change the color of ocean surface waters and are even visible from satellites orbiting Earth.
Every schoolchild knows that baleen whales, the biggest animals in the sea, subsist on huge quantities of krill, which are small zooplankton. But ocean food webs (the linkages between predators and prey) are far more intricate than this familiar example. Many types of plankton eat other plankton. . . . Some plankton have the ability to function as plants (carrying out photosynthesis) and animals at the same time. Others secrete elaborate mineral skeletons of calcium carbonate or silica. Still others live in complex symbiotic relationships with partner organisms. One type of gelatinous zooplankton—the appendicularians—has remarkably fine mesh feeding filters that trap the smallest bacteria in the ocean, leading to a size difference between the consumer and prey comparable to the size difference between whales and krill. Most fishes also eat some types of planktonic prey, especially in the crucial larval stages when availability of just the right kind of zooplankton at the right time and place can determine their survival.
Christian Sardet is cofounder and emeritus research director of the Laboratory of Cell Biology at the Marine Station of Villefranche-sur-mer and creator of the Plankton Chronicles project.
Mark Ohman is professor of biological oceanography at University of California, San Diego.
Excerpted from the prologue to Plankton by Christian Sardet (University of Chicago Press, 2015) with permission from the publisher. Spurgeon epigraph added by the editors.
Also in this Issue
Issue 30 / September 3, 2015- Editor's Note from September 01, 2015
Issue 30: Picturing plankton, the rarely told story of the first missionary to the Muslims, and the arresting burning bush. /
- Before We Conquer, Have We Tried Love and Prayers?
Remembering the first missionary to Muslims, 700 years after his death. /
- Stay By the Fire
The God who makes himself known as flame wants to hold our gaze. /
- The New Creation
‘A choir of a thousand tongues / singing we’ll no longer toil.’ /
- Wonder on the Web
Wonder on the Web Issue 30: Links to amazing stuff /