Mechanic reports removing a leading edge bulb seal that was damaged during a pre-departure deicing on a DHC-8-Q400.

Narrative

I removed a bulb seal (Part #85720300-113) on panel 613DR of Aircraft X. During deicing; the bulb seal (Part #85720300-113) on panel 613DR of aircraft was uprooted. The aircraft was full of passengers. I was advised by a more senior Mechanic to take it off the aircraft for him. He had seen leading edge on other aircraft in hangar with missing bulb seal before; it does not affect airworthiness. We were under pressure to get the aircraft so that they would not have to re-deice. The more senior Mechanic said that he had seen the other aircraft with missing bulb seals similar to this one before. His advice was to remove it and let the aircraft go because it does not affect airworthiness. Callback conversation with reporter revealed the following information: Reporter stated he removed the torn left hand leading edge bulb seal on the DHC-8-Q400; because he believed the senior mechanic was more knowledgeable about what was required; or not required; for bulb seals on the leading edge. But; he did not make a write-up for the condition. Reporter stated he later notified the downline station about the removed seal.