Shipwreck - State of Preservation

State of Preservation

Many factors determine the state of preservation of a wreck:

• the ship's construction materials
• the wreck becoming covered in sand or silt
• the salinity of the water the wreck is in
• the level of destruction involved in the ship's loss
• whether the components or cargo of the wreck were salvaged
• whether the wreck was demolished to clear a navigable channel
• the depth of water at the wreck site
• the strength of tidal currents or wave action at the wreck site
• the exposure to surface weather conditions at the wreck site
• the presence of marine animals that consume the ship's fabric
• temperature
• the acidity (or pH), and other chemical characteristics of the water at the site

The above mentioned, especially the stratification (silt/sand sediments piled up on the shipwrecks) and the damages caused by marine creatures is better described as "stratification and contamination" of shipwrecks. The stratification not only creates another challenge for marine archaeology but also a challenge to its primary state, the state that it had when it sank.

Stratification includes several different types of sand and/or silt, as well as tumulus and encrustations. These "sediments" are tightly linked to the type of currents, depth, and the type of water (salinity, pH, etc.), which implies any chemical reactions that would lead to affecting the hypothetical/possible main cargo (such as wine, olive oil, spices, etc.).

Besides this geological phenomenon, wrecks also face the damage of marine creatures that create a home out of them; primarily being octopuses and crustaceans. These creatures affect the primary state because they move, or break, any parts of the shipwreck that are in their way, thereby affecting the original condition of amphorae, for example, or any other hollow places. Finally, in addition to the slight or severe destruction marine animals can create, there are also "external" contaminants, such as modern-day commodities, or contemporary pollution in bodies of water, that as well severely affect shipwrecks by changing the chemical structures, or even destroying or devastating even more of what is left of a specific ship.

All the above offers great challenges to the marine archaeologist when attempting to bind the pieces of a certain shipwreck together. Despite these challenges, if the information retrieved does not appear to be sufficient, or a poor preservation is achieved, authors like J.A. Parker claim that it is the historical value of the shipwreck that counts, as well as any slight piece of information and/or evidence that is acquired.