Does the displacement of a ship increase over time and if so why?

-I was reading an article about the royal navies new type 45 destroyers, and the displacement of the ship was described as being "8900 tons (at start of life)". When reading a description of a ship the displacement of a ship is often referred to as the displacement which the ship has at the beginning of its life. Does this mean that the weight of something constructed from metal or particular types of metal increases over time by a certain extent? And if this is the case does this only happen to ships, perhaps because of the way in which salt water reactes to the ships hull or something like that, or does this also happen to airplanes, cars etc.Displacement can increase internally and externally.



Internal reasons: Cargo, People, updated equipment, And water leakage into the ship..



External reasons: Barnacles, other sea creatures, Damage repairs, and coats of re-painting.
It means that ships are usually added to, refitted, and otherwise modified on a more or less continual basis, and that such modifications have probably changed the original displacement.