is one piece episode 145 filler?

A turtle-like Sea King surfaces near Nami and the crew. The Masira Pirates are also frightened and scream for their captain, who is underwater confronting Luffy.

Robin finds that the air hoses of the crew's diving suit were in the monster's mouth and deduces that Luffy, Sanji and Zoro were eaten by the monster. The monster pulls the Going Merry via its air hoses and tries to pull it underwater and Nami was about to cut the hoses to free the ship but the sky suddenly changes to night.