Construction Works and Underwater Cultural Heritage

Divers measuring a structure in Pavlopetri, oldest sunken city of the world, and which is threatened by industrial activities © J. Henderson

Today, coastlines, oceans and the seabed are increasingly exploited and used for economic activities. Infrastructure projects in waterfronts or coastal areas, such as harbor extension or dredging projects, bridge construction, pipeline and cables lying, although necessary for the economy and the well-being of society can have a great impact on submerged archeological heritage, which is frequently in particular present close to the coast. Many of these activities impact on the environment by creating pollution, erosion or changing currents, and many of them can affect sites holding submerged cultural heritage, such as sunken cities or ancient shipwrecks.

The question of how to mitigate these extensive industrial, non-desired and non-intended impacts arises. The pressure on Heritage Managers is serious and it is their duty to valorize and protect the underwater cultural heritage.

The UNESCO 2001 Convention says in its Article 5: “Each State Party shall use the best practicable means at its disposal to prevent or mitigate any adverse effects that might arise from activities under its jurisdiction incidentally affecting underwater cultural heritage.”

The Convention thus clearly encourages States to enact national legislation obliging enterprises to take into account underwater heritage, to assess its presence and significance and to mitigate any potential impacts.

 With wise planning and collaboration, not only excellent results for heritage protection and the development of underwater archaeology can be achieved, but also the enterprises concerned can benefit in terms of corporate responsibility and public image.


An example of coastal development and heritage:

Angra bay, the Azorean harbour that served Angra city, a UNESCO World Heritage Site renowned since the Age of Discoveries, is no larger than 10 soccer fields. In spite of having such a humble size of the area, between 1522 and 1998 at least 96 shipwrecks have occurred there.  Angra bay was turned into a classified underwater archaeological preserve in 2005. However, the bay is now designated to be the location of a Transatlantic Cruising Ship Pier. This will impact the scores of historical wrecks still to be discovered under its sandy bottom way beyond any mitigation measures that might be taken.

The case of Angra bay is an example of how the fundamental protection of underwater cultural heritage is not carved in stone and how nautical archaeologists must have their voices heard in the discussion on development, where and at what cost.

Find out more here.

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