is one piece episode 586 filler?

The centaurs are still shooting, aiming for the bottom of the boat to sink the Straw Hats. Brownbeard smugly tells them that they will not escape from him, only for Luffy to ask him who he is.

Brownbeard is shocked and introduces himself. However, the group replies that they have never heard of him.

This caused Brownbeard to be depressed and angered. He fires at them personally and manages to capsize the boat.

After falling into the water, Zoro and Usopp carry Luffy and Robin respectively. Teeth chattering, Usopp complains about the temperature of the water.