SITEMONITORING ANDPROTECTION 167
of the sea-bed may also explain the disappearance
of artefacts.- Deterioration of artefacts:The manner and rate of
artefact deterioration should be considered. This can
be assessed through, for example, the comparison
of close-up photographs taken at regular intervals
or by the close visual examination of artefacts,
perhaps looking for the effects of marine wood-
boring organisms. Such assessments may help to
determine whether the recovery of the artefact or
in situprotection is required. Deterioration may
be due to a number of factors, including erosion,
biological damage and human interference. Rapid
deterioration may require active intervention to
either remove the artefact or protect it in situ. - Corrosion potential:High or fluctuating corrosion
potential may mean that an artefact needs to be
recovered or stabilized in situ.
The project plan should provide for the storage, in one
place, of all the data and documents (including video
and still images) collected during the monitoring project.
This is called the project archive (see chapter 19).
It is incumbent upon the organizers of a monitoring
project to ensure that sufficient time and resources are
allocated to publication of activity and that publication
is undertaken to the recognized archaeological standards
of the country concerned, or to internationally accepted
standards if no national standards exist (see chapter 20).
Monitoring reports and the data on which they are based
are likely to become increasingly available through local
and national archives. Innovative web-based publication
projects using geographical information systems, such
as the pan-European MACHU project (www.machu-
project.eu/), may well transform the accessibility of both
data and technical expertise.
Protection
Protection is a physical or other in situintervention that
results in the slowing, halting or reversal of a process that
is believed to be having a negative impact on an archae-
ological site. It might therefore best be described as ‘sta-
bilization’. Although attempts have been made to protect
sites for many decades, until recently the study of in situ
archaeological protection under water has received little
attention and is therefore still relatively poorly understood.
The legal protection of a site from the adverse consequences
of human activities is considered in chapter 7 and so has
not been dealt with here.
Protection should be considered for sites where a
monitoring programme has shown that the condition of
a site is deteriorating significantly or where serious in-
stability is otherwise apparent. Typical circumstances might
include instances where:- vulnerable archaeological material has become
exposed or is deteriorating and it is undesirable or
impracticable to recover it (e.g. if a fragment of
wooden hull became exposed, which was unique or
had important characteristics, but which was too large
to recover); - archaeological material has been deeply buried
but the depth of burial is no longer great enough
to prevent its condition from deteriorating (e.g. if
it is no longer in an anaerobic environment); - short-term protection is required (e.g. if a site that
is normally buried is uncovered by an exceptional
storm event and reburial by natural processes is
uncertain).
Protection measures should only be considered where
sufficient resources, both time and money, are avail-
able or are very likely to become available. Long-term
monitoring may be required and a project design-led
approach to protection, similar to that required in mon-
itoring work, should be adopted. As with monitoring,
best practice would involve thorough recording and the
publication of work carried out.
A full discussion of all of the techniques that have
been used for the in situprotection of shipwreck sites
is beyond the scope of this book. Nevertheless, a few
examples can be given to show the range of options
that can be considered.Re-burial: If a site has been destabilized because sand
or other overburden has been removed from it, then
simple re-burial can be considered. This is, however,
likely to be successful only in the short term, unless the
process that resulted in the exposure is no longer active.
In the absence of any means of stopping the destructive
process, re-burial with a more resistant material could
be considered (e.g. gravel instead of sand). The physical
and chemical impact of this different material on the
site would have to be considered, together with the risk
of intrusive wreck material being added to the site. The
latter may be particularly significant if dredged sand
or gravel is used to cover the site and it is known to
come from an area of high maritime activity, such as the
approach channel to a port.
The cost of re-burial can be significant, particularly for
a large site, unless a partnership can be forged with an
existing commercial operation.Sandbags: Sandbags can be used to cover a whole site
or, selectively, to reinforce or cover individual or groups
of artefacts. They are resistant to currents and, to a