Shipwreck

Stratification includes several different types of sand and/or silt, as well as tumulus and encrustations. In addition to these, 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. However and despite these challenges, even 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.