What is the cooperative feeding technique used by humpback whales involving rings of bubbles?

The cooperative feeding technique used by humpback whales involving rings of bubbles is bubble-net feeding.

Several whales circle a school of fish while blowing bubbles from their blowholes, creating a rising wall or spiral that concentrates and disorients the prey. The whales then swim upward through the bubble “net” with their mouths open, engulfing fish and seawater. Baleen plates strain the water out while retaining the food.

Bubble-net feeding is especially useful against small schooling fish and krill because it lets whales capture dense mouthfuls with less energy. Groups may coordinate using vocal signals, and the behavior appears to be learned socially rather than performed automatically by every humpback population. Solitary humpbacks can also use related bubble-feeding methods.

A common mix-up is lunge feeding: that technique also involves a whale surging through prey with its mouth open, but it does not specifically use a cooperative ring of bubbles. Humpbacks feed mainly during productive seasons and rely on stored blubber while migrating to breeding grounds.