This video says about itself:
An intelligent technique Humpback Whales use when hunting Herring.
From DPA news agency in Germany:
Stralsund, Germany – A visit to the Baltic Sea by a 12- metre-long humpback whale, only the third recorded by German scientists since 1851, generated excitement Tuesday along the German coast. Harald Benke, director of the Oceanography Museum in Stralsund, identified the whale from a photo taken off the German island of Ruegen. The species, Megaptera novaeangliae, is found in all the world’s main oceans, the environmentalist group Greenpeace said.
German records show one humpback whale was seen in the Baltic several times in 1978 and a predecessor before that in 1851, Benke said.