is one piece episode 846 filler?

Chopper and Brook make it to the juice river where they left the Shark Submerge III, but find the river flooded with cream, which was sent there by the Whole Cake Chateau's collapse. Chopper takes a liking to the cream and ends up eating enough of it to free the Submerge, and the duo head to the Thousand Sunny.

As they go down the river, they spot a merman, and they are confronted by a massive sea beast, which they quickly sail away from. As Luffy's group continues running away from Big Mom, Jinbe reveals that Big Mom is having a tantrum due to her craving for wedding cake.