Generally speaking, the seagull symbolizes negative traits such as gluttony, thievery, gossip, crowd-mentality, and filthiness.
To me however, seagulls symbolize and represent people who are able to find opportunities in what we consider unlikely places, circumstances and situations. Seagulls go where they can find the best food. Reminding us to move where the best resources are, even if it may not be where everyone else is at.
The word “gull” is derived from “gullible”. The correlation behind this stems from the fact that seagulls will swallow anything it can push down its gullet. Symbolically speaking, I must ask: “Do we swallow everything we hear or see?”
This behaviour of the seagull cautions us to observe, rather than blindly follow what we see or hear without further investigation.