Sea Eagles hunting in pair

I witnessed a pair of White-tailed (Sea) Eagles hovering low over the water surface of Lake Fläcksjön. They stayed over the same point so long I realized they must be hunting something in the water below them. They took turns in swooping down to attack the prey. The wind was strong at the moment so they seemed to have a hard time, but they were ever so persistent. After several minutes and seemingly endless attempts, one of the birds came up with a duck in it´s talons. They had managed to exhaust the bird til it finally got possible to grab when it re-surfaced. I´ve seen this before with Coot and Great-crested Grebe for prey. This time it looked like a Mallard. Sorry the poor picture quality but the documentary aspects justifies!