The decomposition of wood in the Baltic Sea is a very slow process, as the oxygen and salinity levels as well as the temperature are low.
When Vasa was salvaged, the wood came into contact with oxygen, and a number of decomposing reactions started. Substances that previously were stored in the wood also have an influence in the degradation, above all sulfur and iron in various forms. The degradation of Vasa has resulted in the strength of Vasa's wood being greatly reduced, among other things.
However, if Vasa had not been salvaged, we would not have been able to experience and learn from the magnificent source of knowledge the ship is. Based on the research that has been carried out, we believe that the strongest impact occurred during the time immediately after the salvage, and that the degradation has now slowed down. To make sure of this, we continue to investigate the rate of degradation together with researchers. Among important measures that have already been implemented, and are underway, are a stabilized climate in the museum and improved support of the ship.
The work to preserve Vasa is continuous and can be of help to other museums in the world – in their work with preservation of wooden objects.