Vicki Richards

In situ conservation surveys of iron shipwrecks in Chuuk Lagoon and the impact of human intervention

Abstract Regular site inspections are an integral part of the overall management strategy for a submerged site. The primary focus of an on-site corrosion survey is to collect as much pertinent information as possible to assist in ascertaining the extent of deterioration and structural integrity of a site. Further inspections are then required at regular intervals so any changes in the integrity of the site are noted by direct comparison with earlier surveys. The more surveys carried out, the better, as they will provide more information regarding the rate of deterioration and the inherent stability of a site, which will assist in recognising which sites are a priority for future implementation of appropriate in-situ conservation management strategies. Hence, as an example, over a five-year period, a series of in situ conservation surveys were performed on a selected number of World War II Japanese wrecks located in Chuuk (Truk) Lagoon, in the Federated States of Micronesia. During World War II, the Japanese established their principal military naval base at Chuuk (Truk) Lagoon but in February 1944, American forces attacked the base and consequently, many of their ships were sunk and a number of aircraft were lost in the lagoon. These wreck sites have become very popular dive sites and therefore, Chuuk Lagoon has become one of the major recreational dive destinations in the world. As unsustainable fishing practices have become more prevalent in this area and with the downturn in the tourism industry due to the global economic crisis, it is very important to monitor the archaeological, biological and structural integrity of the wrecks in Chuuk Lagoon, so early intervention may prevent loss of these internationally significant underwater cultural and natural heritage sites, which are intrinsically linked to the economic future of the local Chuukese people.

In Situ Preservation and Monitoring of the James Matthews Shipwreck Site

Abstract Over the past few decades, the archaeological community has been moving away from the more traditional methods of excavation and recovery of underwater cultural heritage towards a less intrusive management approach, essentially involving the preservation of sites in situ. This trend has been politically galvanized in Article 2, point 5 of the Convention on the Protection of the Underwater Cultural Heritage (), which states that ‘The preservation in-situ of underwater cultural heritage shall be considered as the first option before allowing or engaging in any activities directed at this heritage’. Over the years, a number of different remediation strategies have been utilized in order to protect underwater cultural heritage sites in situ, and most of the techniques or combinations thereof involve reburial of sites. Reburial may be an appropriate means of stabilizing and decreasing the deterioration rate of a site, however, there needs to be a holistic approach to the study of the environment, before and after reburial, to gain a full understanding of the changes that are occurring on the site and determine the effectiveness of the technique. In early 2000, the James Matthews, a copper-sheathed, wooden-hulled vessel wrecked in 1841 south of Fremantle, Western Australia, was identified as being under considerable threat from increased site exposure due to a combination of natural near-shore sedimentary processes and industrial activity in the immediate area. An extensive on-site conservation survey was carried out to establish the state of preservation of the wreck and provide information regarding the physico-chemical and biological nature of the environment prior to the implementation of any mitigation strategy. In 2003 it was confirmed that further exposure of the site was occurring and devising a management plan was of paramount importance. Since this time a number of different reburial techniques have been trialled on the site and these include sand bags of differing material composition, polymeric shade cloth, artificial sea grass mats made from polyvinyl chloride bunting, and the use of interlocking medium density polyethylene ‘crash barrier’ units in a cofferdam arrangement to confine deposited sand. The geological, physico-chemical, and microbiological changes in the burial environments have been monitored over this time. Furthermore, the broader scale, near-shore sedimentary processes affecting the site are being assessed in order to establish the reasons behind the continuing sediment loss. In situ preservation of the iron fittings by cathodic protection has also been included in these field trials. In this paper the results from these experiments will be summarized. This information will be used to finalize the design of the full-scale in situ preservation strategy for the site and assist in establishing a post-reburial monitoring programme that will measure the success of the adopted remediation technique.

In situ preservation and reburial of the ex-slave ship James Matthews

Abstract The James Matthews (1841) was a copper-sheathed, wooden-hulled vessel, constructed in France in the late 1700s. During the 1830s, it operated in the illegal slave trade between Africa and America until it was captured by the British in 1837. The ship was re-registered and in 1841, the ship sailed for the Swan River colony in Fremantle, Western Australia but the day after arrival in Careening Bay, near Woodman Point, a violent storm struck and the vessel was wrecked on 22 July 1841. The James Matthews has been identified as historically and archaeologically important not only because of its significance to the early colonial history of Western Australia but because the near-complete starboard side of the vessel remains intact. As most of these types of vessels were destroyed when captured under the anti-slave trade legislation of the time, it is one of the world’s best-preserved examples of a 19th century purpose-built illegal slaver. However, over the past few years, the site has been under considerable threat from increased exposure due to natural near-shore sedimentary processes and localised industrial activity. Therefore, devising a comprehensive, appropriate and cost-effective remediation strategy to significantly reduce the continued deterioration of this historic shipwreck site is of paramount importance. A number of different reburial techniques are currently being trialled on the site and the results of these experiments will assist in implementing the most appropriate mitigation strategy for the long-term preservation of this important wreck site.

The Australian Historic Shipwreck Preservation Project: In situ Preservation and Long-Term Monitoring of the Clarence (1850) and James Matthews (1841) Shipwreck Sites

Increasingly, archaeologists are opting for on-site examination, reinterment, and in situ preservation of underwater cultural heritage sites as the first option in the management of sites at risk, as opposed to the more traditional excavation, recovery, conservation, and display/storage methods. This decision will inevitably be based on significance assessment, degree of perceived risk, and resourcing issues. However, long-term monitoring must become an integral part of these management programmes in order to quantitatively evaluate the effectiveness of the in situ preservation techniques employed. In 2012 the Australian Historic Shipwreck Preservation Project (AHSPP) was awarded a large Australian Research Council (ARC) Linkage Grant, enabling ten partner organizations and three Australian universities to collaborate in one of the largest multi-organizational maritime archaeology projects to be undertaken in Australia to date. One of the major aims of the project is to develop a protocol for the excavation, detailed recording and reburial of significant shipwrecks under threat, fostering a strategic national approach for the management of underwater cultural heritage (UCH) sites at risk. Two historically significant shipwreck sites that are considered under threat were chosen for this longitudinal comparative study — the Clarence (1850) located in Port Phillip Bay, Victoria; and the James Matthews (1841) which lies in Cockburn Sound, Western Australia. Both sites have been preserved in situ using two very different but innovative remediation strategies. More importantly, long-term monitoring programmes have been implemented on both sites, which will characterize changes in the reburial environment and the effect on the reinterred materials. In this way, the efficacy of both in situ preservation techniques will be systematically tested, providing a comparative analysis of practical protocols for the long-term protection and management of underwater cultural heritage.

Reburial and Analyses of Archaeological Remains in the Marine Environment — Investigations into the Effects on Metals

Abstract The treatment and long-term storage of recovered cultural material from underwater heritage sites is becoming less cost effective, and reburial of archaeological sites and the associated artefacts in the marine environment is becoming increasingly common practice in managing the submerged cultural resource. Following recent large-scale underwater archaeological excavations in Marstrand harbour, Sweden, the majority of recovered finds were reburied in defined trenches in the harbour sediment. Subsequently, the Studio of the Western Sweden Conservators in conjunction with the Bohus County Museum initiated a fifty-year research project to evaluate reburial as an appropriate method of preserving waterlogged archaeological artefacts in the long term. The research project, entitled ‘Reburial and Analyses of Archaeological Remains’, was launched in 2002 and consists of six sub-projects. The main aims of these sub-projects are to analyse the extent of deterioration of the most common material types found on underwater archaeological sites, assess the stability of packing and marking materials used in archaeological documentation, and monitor the reburial environment. The aim of the metals sub-project is to investigate the short- to long-term corrosion behaviour of metals buried in the marine environment by examining the deterioration of reburied and exposed modern metal coupons and eventually compare these results to the analysis of actual shipwreck artefacts. The environmental monitoring sub-project is designed to complement the other sub-projects by assessing the physico-chemical changes occurring in the reburial environment over time and the effect on the deterioration of the different reburied material types. In comparing the results obtained over the past seven years from both the metals and monitoring sub-projects, it should be possible to more accurately evaluate the effectiveness of reburial as a long-term in situ preservation strategy for metallic archaeological remains.

The RAAR Project — Heritage Management Aspects on Reburial After Ten Years of Work

Abstract The general purpose of the international reburial project, Reburial and Analyses of Archaeological Remains (RAAR), is to evaluate reburial as a method for the long-term storage and preservation of waterlogged archaeological remains. Since 2001 material samples have been buried, retrieved, analysed systematically, and the results reported. RAAR has mainly focused on the degradation of materials commonly encountered on archaeological sites, and on environmental monitoring techniques in order to determine what type of material can be reburied and for how long. The project has concluded that a heritage institution could provide short- or long-term curation for its archaeological archive by using reburial depots provided they are set up according to guidelines and restrictions stipulated by the RAAR project. However, there are management and legal aspects that need to be discussed and resolved before each reburial project. Actual reburials that have been carried out so far are often a solution to emergency situations and lack collection and management policies. The questions ‘what’, ‘why’, and ‘for how long’ have been forgotten and need to be addressed. The legal protection of a reburial site is also important. This paper discusses these aspects and their consequences and highlights possible differences in approaches between the countries involved in the RAAR project.