is one piece episode 277 filler?

Professor Clover is allowed to speak with one of the Five Elders and does a report of their research. He describes a civilization that existed hundreds of years ago and vanished at the time that the World Government assumed power.

He considers the collective evidence, which leads him to believe that the government tried to erase their former enemies from history. After stating that Ohara has learned too much, the Five Elders orders Spandine to kill the professor and to give the order to destroy the island.