Plankton in peril

Zooplankton under a microscope at the Bigelow Laboratory for Marine Sciences in East Boothbay, Maine. — Billy Hickey/The New York Times

HUMANS live in a plankton world. These minuscule organisms blanket the oceans, covering nearly three-quarters of the planet, and are among the most abundant forms of life on Earth.

But as the world warms, plankton populations are shifting, with consequences that ripple through the entire marine food chain.