Page 205 - Manual for Activities directed at the Underwater Cultural Heritage

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is an important element in a management plan. It allows understanding the processes affecting the site (including biological surveys on the impact of micro and macro organisms) and thereby facilitates the design of protection measures. Monitoring schemes are particularly important for instable sites and sites of great significance. They are implemented following a bench-mark or reference investigation of the site with regards to its composition, distribution and biology, seabed, current and water characteristics, and extend to factors such as human interference.
Protection against interference
This aspect should be considered for the long-term as well as in the course of fieldwork. A site that is under excavation is particularly vulnerable to interference. In preventing the interference of others, secrecy is not an option. It is hardly possible to secretly operate at the same underwater spot for any length of time. This will attract attention, even in the open sea. At sea, any continued presence on a spot without expli- cation is suspect. Moreover, buoys and shot lines are the obvious corollaries of any underwater operation and as such, they attract attention and interference if unexplained.
Through proper public information, the prolonged and repeated presence of a team can be well-explained
 © NOAA. Complete profile mosaic of the Defiance, sunk in Lake Huron, United States.
On 20 October 1884, the Defiance and the John J.Audubon sunk after a collision on Lake Huron.
A NOAA-led research expedition in June 2010 in Thunder Bay National Marine Sanctuary
has documented the sites
with carefully drawn survey maps, individual and panoramic photographs, and video.The research has not only revealed the stories preserved in these nationally-significant shipwrecks, but it will be critical in their long term preservation.The sanctuary will use this baseline analysis to monitor future changes to the shipwrecks.
Conservation and site management