I was in Alaska 25-30 years ago and got to observe first hand a pod of humpback whales doing what the naturalist on our trip called "bubble net fishing." Whales don't usually hunt cooperatively, but during the days before they migrate to the waters between Maui and the Big Island of Hawai'i they need to fatten up. Anyway, a couple of females will swim a mile or so from a central area where fish will be concentrated, while loudly slapping their flukes on the surface of the water. This 'concentrates' the bait fish, scaring them towards the center. The matriarch of the pod goes sounder and dives deep underneath where the bait fish are schooling.
The remaining whales form a cylinder of sorts around where the fish are schooling. The matriarch starts slowly releasing air bubbles beneath the ball of bait fish causing them to form into a denser pack that forces the column towards the surface. The whales on the outside of the cylinder start tightening the noose. Soon you begin to see the surface of the water start to boil as the panicked bait fish are squeezed tighter and tighter up to the surface. No sooner than you see some panicked fish splashing out of the water, the matriarch and the whales on the periphery broach the surface, their jaws wide open, swallowing thousands of bait fish while thrusting nearly half their body length out of the water.
Obviously, you don't want to be a kayaker in the middle of that buffet line. It was one of the most amazing things I've ever witnessed in nature.