I was harvesting some resources to upgrade the Jackdaw and building up my wanted level on the high seas the other night. I know I can lower this by bribing the proper NPC on shore or boarding a ship and choosing to reduce my wanted level. In this case I am trying to build it up so pirate hunters start sending Man-O-Wars at me so I can beef up Kenway's Fleet.
I was not exclusively building my wanted level and was doing some story events, exploring, and harpooning along the way, but I eventually noticed I was back down to 1 mark on my wanted level. I do not remember for sure what I did, but I am pretty sure I did not intentionally lower my wanted level. Does doing story missions or exiting the game reset my wanted level?
Generally: Other than bribing and choosing to reduce it after boarding a ship, what events reduce or reset your wanted level?