http://www.sciencemag.org/news/2019/01/fishing-industry-leaving-enough-food-antarcticas-top-predators

Krill feed on phytoplankton and are a critical part of the food web.

Krill, crustaceans smaller than a cigarette, play an outsize role in the ecology of the ocean around Antarctica: Penguins, whales, and other predators feast on vast swarms of the shrimplike animals. Now, researchers have launched a broad international survey of krill’s main habitat in the Scotia Sea—the first in nearly 20 years—to learn whether a growing fishing industry is leaving enough for krill’s natural predators.