Found in a junk store in New Bedford, MA… Album of Whales (1980) by Tom McGowen, with great illustrations by Rod Ruth of baleen-bearing beasts basking on plankton.
When humpback whales like this guy above are not hunting herring, they crave krill and other plankton.
Right whales were hunted early and often by humans, due in part to their surface feeding habit of “skimming” for zooplankton.
Baleen feeding whales essentially scoop up a huge volume of seawater and then expel it through their baleen “teeth” with their mouths closed. Krill and other treats like copepods stay in the mouth. To me its just a trip that these enormous animals can get enough tiny bits (billions of plankton per day) to satisfy the appetite.