Underwater Cultural Heritage Sites Research Articles

IBLUECULTURE: A NOVEL SYSTEM OF REAL-TIME UNDERWATER IMAGE TRANSMISSION IN A VIRTUAL REALITY ENVIRONMENT, AS A NEW MANAGERIAL APPROACH FOR UNDERWATER CULTURAL HERITAGE

Abstract. The Mediterranean is rich in ancient and modern shipwrecks and submerged sites of great archaeological, historical, and cultural value. Most of those sites tend to be relatively unknown, even to people living in the area, mostly due to the inherent limitation in physical approach. As a result, these sites are left unknown and unprotected. The aim of the iblueCulture project was to create a system that can make Underwater Cultural Heritage sites broadly accessible and raise public awareness on their location, content, and value. This approach is also meant to provide an effective management strategy for the constant, real-time monitoring and, therefore, protection of such sites, while in accordance with the sustainable tourism development goals for islands and coastal areas. This project, as implemented, can offer an immersive dry dive experience to the public, while providing management bodies and stakeholders with the capability of remotely monitoring the UCH sites in real-time, through live-streaming video. This ability can be vital in some cases, especially when involving sites in greater depths or in remote areas with little maritime traffic. The system is also expected to assist in underwater research, especially in deep water sites, and other educational activities or possible scientific research.

How Do Underwater Cultural Heritage Sites Affect Coral Assemblages?

Underwater cultural heritage sites (UCH), such as shipwrecks and sunken aircrafts, can provide physical structures to support coral recruitment and habitats for marine organisms. Conversely, these archaeological artifacts can also be detrimental to live coral and release pollutants into the environment. The military history of Guam has resulted in a high abundance of UCH sites on shallow coral reef habitats, and little is known about how these artifacts may affect the ecology of these natural systems. In this study, we used photogrammetry techniques to survey coral assemblages on both natural and artificial reef substrata. We statistically examined patterns in coral cover, diversity, richness, and 3D habitat complexity. Our results found significant differences in live coral cover and assemblage structure between natural and artificial reef substrata. The results from univariate modeling and multivariate analyses indicate that coral assemblage structure plays an important role in supporting 3D habitat complexity, and the archaeological artifacts themselves can be a significant source of habitat structure. There is still a lack of clarity as to the overall implications of archaeological artifacts on underwater habitats, and the approach described here can be applied elsewhere to better understand the ecological impacts of UCH sites on coral reefs.

Application of Parametric Sub-Bottom Profilers for Responsible in Situ Management of Underwater Shallow-Buried Archaeological Materials

The application potential of parametric sub-bottom profilers (SBPs) to in situ management of underwater archaeological sites at risk from degradational loss of shallow-buried materials is presented. This approach is based on the process-driven in situ preservation and research frameworks advocated by the 2001 UNESCO Convention on the Protection of the Underwater Cultural Heritage and provides a basis for greater uptake by the archaeological community. Results from research at a purposely prepared sub-seabed site and on the adjoining James Matthews (1841) wreck site in Western Australia demonstrate how noninvasive SBP-derived data support responsible management of underwater cultural heritage (UCH) sites by: (1) identifying and/or confirming the presence of sub-seabed UCH material, (2) identifying the potential level of risk of further material loss from ongoing degradation, (3) providing key information with which to make a sound in situ management or site-research plan for the sub-seabed material, and (4) delivering monitoring feedback regarding the success of in situ management actions.

Problematic aspects of the legal status of underwater cultural heritage sites

Problematic aspects of the legal status of underwater cultural heritage sites

Underwater Cultural Heritage: Out of Sight, Out of Mind and at Risk

OUT OF SIGHT, OUT OF MIND. Tangible and intangible cultural heritage assets located in coastal and near-shore underwater environments are under particular threat due to climate change and its impact on water. These threatened sites and practices have served historically to not only feed and employ large and small coastal communities, but importantly have provided the societal and cultural roots that have helped bond them together. Although it is acknowledged that water environments (in the context of this article ‘‘water’’ is taken to mean oceans, seas and inland waters) function as a major global food source (SDG 2 Zero Hunger), and play a major role as a carbon sink (SDG13 Climate Action), water is also a vehicle for commerce and many other ocean activities labeled ‘‘the Blue Economy,’’ all of which are considered of critical importance. However, the societal consequences of damage and loss to underwater tangible and intangible heritage assets and associated practices should not be underestimated. Threatened by sea level rise, with seas estimated to rise by up to a meter by the end of the century, combined with extreme weather events (Gregory et al. 2022), it is anticipated that there will be significant loss of these assets with social and cultural consequences. In extreme circumstances, the very existence of some coastal communities and Small Island Developing States (SIDS) is also at risk. Therefore, how to value, protect and manage these often “unseen” underwater cultural heritage sites sustainably is of vital social and cultural importance.

RETRACTED: Applying geoarchaeological principles to marine archaeology: A reappraisal of the “first marine” and “in situ” lithic scatters in the Dampier Archipelago, NW Australia

AbstractThe absence of known prehistoric underwater cultural heritage (UCH) sites on the Australian inner shelf stands in stark contrast to the thousands of sites revealed elsewhere in the world. Two recent claims—Dortch et al. (D2019) and Benjamin et al. (B2020)—put forward the first in situ (i.e., primary context) UCH sites in the shallow waters of the Dampier Archipelago, North West Australia, each arguing that the stone artefact scatters are at least 7000 years old and are now submerged because of postglacial sea‐level rise. We present new hydrodynamic modelling and data on coastal erosion and bathymetry, and reassess each site's sedimentary setting and archaeological site‐formation history. D2019 and B2020 clearly present lithic cultural artefacts, but the arguments for their sites being of primary context and reflecting early Holocene land surfaces are mistaken. Rather, these sites occur in the intertidal zone, and many or all artefacts are likely to have been reworked. Sites of secondary context, if treated appropriately, can inform our understanding of site‐formation process and change, and may support more powerful contributions to submerged archaeology than attempts to seek the first or the oldest.

Motivations And Attitudes of Egyptian Divers in Underwater Cultural Heritage Sites

Motivations And Attitudes of Egyptian Divers in Underwater Cultural Heritage Sites

A Roadmap for the Sustainable Valorization of Accessible Underwater Cultural Heritage Sites

This paper presents a roadmap to enable the adoption of the BLUEMED model; an integrated plan developed within the BLUEMED project that promotes underwater cultural heritage (UCH) to both divers and non-divers and aims at sustainable tourism development in coastal areas and islands. Through augmented and virtual reality technologies, one can experience wet and dry diving to accessible underwater cultural heritage site(s) (AUCHS), through a physical dive at the sites or a virtual tour at Knowledge Awareness Centers (KACs). The roadmap provides guidelines, so that relevant stakeholders and competent authorities can implement the BLUEMED model and consider the various environmental, cultural, and socioeconomic factors of the area (locality), to ensure viability in the long-term. The roadmap focuses on the policy and technical parameters, including the cultural and environmental features of the site, the legislative framework, funding issues, the integration of technologies, the prospects for sustainable tourism development in the area, the stakeholder engagement, and the cooperation framework within a top-down or a bottom-up initiative, as well as the establishment and operation of the KACs.

Implementing Multi-Criteria Analysis in the Selection of AUCHS for the Integration of Digital Technologies into the Tourism Offering: The Case of MeDryDive

Focusing on both physical and virtual accessibility, this paper presents the methodology developed by MeDryDive for the selection of AUCHS (Accessible Underwater Cultural Heritage Sites) in Greece, Italy, Croatia, and Montenegro. MeDryDive is a project that aims at the promotion of AUCHS in the Mediterranean as distinctive tourism destinations through personalized dry dive experiences. The candidate sites are assessed in order to be included in the transnational thematic tourism product “Dive in the Past” and promoted through Creative and Cultural Industry (CCI) applications, including a Serious Game, Augmented and Virtual Reality applications, and promotional videos, all developed in the context of the project. The main goal of the methodology is to meet the requirements for both the sustainability of the thematic tourism product and the digital applications’ development. The assessment of AUCHS is based on specific criteria that result from setting weighing factors and classifying indicators as either critical or non-critical. The criteria are categorized into core (feasibility) criteria and complementary (appropriateness) criteria for determining the total level of readiness. This set of criteria enables site selection through an elimination method, identifying the suitable pilot and follow-on sites for the integration of digital technologies into the tourism offering.

The Innovative and State of the Art Public Access Management of Malta’s Underwater Cultural Heritage

The obligation to preserve underwater cultural heritage is a core principle of the UNESCO Convention on the Protection of the Underwater Cultural Heritage. A key element of this obligation is a balance of scientific research, protection, and the promotion of responsible access to underwater cultural heritage sites. Such a balance requires the setting up of a network of communication between the tourism and heritage sectors on the one hand and the maritime and diving communities on the other hand. A variety of approaches have been developed to promote responsible access to underwater cultural heritage sites, and since the vast majority of the public does not dive, this also includes the development of virtual access. In Malta, maritime archaeology can be traced to humble and sporadic beginnings in the 1950s. The following decades brought a growing interest in diving activities and a rising number of diving schools and clubs. Whilst Malta has today established itself as a diving tourism destination, responsible access to underwater cultural heritage sites was not always entrenched in dive operations or institutionally recognized. The protection and management of underwater cultural heritage has recently been firmly established within Heritage Malta, the national agency for museums, conservations, and cultural heritage. This paper is intended to outline the trajectory of Malta’s underwater cultural heritage management and to present the innovative and state of the art public access system that is managed by the Underwater Cultural Heritage Unit within Heritage Malta.

From Discovery to Public Consumption: The Process of Mapping and Evaluating Underwater Cultural Heritage in Malta

The in situ promotion and preservation of underwater cultural heritage sites is one of the main ideas of the UNESCO Convention on the Protection of Underwater Cultural Heritage. Currently, most shipwrecks are found in water shallower than the 50 m contour. The continued technological advances and increases in technical diving and deep-water exploration point towards a shift in this statistic, which is set to increase exponentially in the not-too-distant future. Thus, it is imperative to look at ways in which such directives can be implemented. This paper will highlight the synergy between existing remote sensing technologies and the management of underwater cultural heritage with examples of on-going research projects, such as Malta’s approach to surveying and implementing a scoring system for historic wreck sites based on local and global considerations of historic and natural conditions of site elements. Such an approach allows for the scaling of sites based on a number of parameters and provides instructive information for the creation of management strategies. The intention here is to demonstrate how large-scale remote sensing surveys can make major contributions to site management, which, in turn, facilitates the decision-making process in terms of how and what information is transmitted to divers and members of the public.

Evaluating the Potential of Augmented Reality Interfaces for Exploring Underwater Historical Sites

Underwater cultural heritage sites represent an attractive and exciting experience for diving tourists, even if often it is complicated for them to understand the significance and value of the remains that are usually strongly damaged and covered by the marine organisms. Thanks to the recent advancements in technologies that overcome these problems, augmented reality is nowadays possible even in such harsh conditions, opening new possibilities for enhancing the diver’s experience. However, no user study has formally evaluated the usefulness and usability of augmented reality in open sea underwater environments. This paper presents two novel solutions for underwater augmented reality: a compact marker-based system for small areas, and a complex acoustic system for large areas. Both of them were deployed at an underwater cultural heritage site and evaluated by ten divers in experiments analyzing their perception and remembrance, interests, and user experience. For comparison, the same study was also performed with non-divers assessing the marker-based system on land. Results show that both systems allow divers to encounter new and exciting moments and provide valuable insights for underwater augmented reality applications.

A multi-camera system for the integrated documentation of Underwater Cultural Heritage of high structural complexity; The case study of M/S Helma wreck

High structural complexity is quite common in underwater archaeological sites and perhaps on top of the list when it comes to challenges regarding 3D reconstruction. Advances in underwater robotics and optical sensors are providing solutions for high quality data acquisition for mapping and documentation of underwater cultural heritage (UCH) sites. This paper presents a workflow for the detailed 3D reconstruction of a disintegrated shipwreck from the 1920’s in Trondheimsfjord, Norway, a wreck site of high 3D structural complexity at 55 meters depth. The work focuses on the use of seven multi-purpose optical sensors, like low-cost action cameras, omnidirectional cameras, a depth camera and an RGB camera attached to an Underwater Hyperspectral Imaging sensor, all mounted on a Remotely Operated Vehicle (ROV). The 3D reconstruction of the wreck site was carried out offline, through the implementation of a typical Structure-from-Motion pipeline. Only one camera, considered as the master camera of the system, was connected to the ROV’s control system and to the navigation sensors, hence providing georeferenced images. With the assumption that all seven cameras were moving jointly in 3D space, an approach for estimating the relative positions of the six stand-alone cameras, with respect to the master camera, was followed. The geometric configuration of the multi-sensor system allowed scaling and georeferencing of all created 3D models, and a more rapid alignment process of the big amount of collected imagery data. The presented case study highlights the advantages of multi-vision setups for UCH documentation, such as near 360° field of view with robust geometry; full 3D coverage of challenging objects of interest; the possibility of sensor’s synchronization invariant approaches, and not least minimization of maneuvering and bottom time.

The Accessible Underwater Cultural Heritage Sites (AUCHS) as a sustainable tourism development opportunity in the Mediterranean Region

This article is about the multi-dimensional value of the Accessible Underwater Cultural Heritage Sites (AUCHS) for coastal areas and islands in the Mediterranean Region, especially as an opportunity for sustainable blue growth. It is an attempt to underline the need for the broad promotion of Underwater Cultural Heritage (UCH) and to highlight the contribution of innovative technologies for direct and indirect accessibility to underwater cultural heritage remains. The paper further demonstrates how the AUCHS can become niches of touristic development for an area whilst offering multifaceted socioeconomic benefits to the local communities.

Marine Robots Mapping the Present and the Past: Unraveling the Secrets of the Deep

Underwater cultural heritage sites are subject to constant change, whether due to natural forces such as sediments, waves, currents or human intervention. Until a few decades ago, the documentation and research of these sites was mostly done manually by diving archaeologists. This paper presents the results of the integration of remote sensing technologies with autonomous marine vehicles in order to make the task of site documentation even faster, more accurate, more efficient and more precisely georeferenced. It includes the integration of multibeam sonar, side scan sonar and various cameras into autonomous surface and underwater vehicles, remotely operated vehicle and unmanned aerial vehicle. In total, case studies for nine underwater cultural heritage sites around the Mediterranean region are presented. Each case study contains a brief archaeological background of the site, the methodology of using autonomous marine vehicles and sensors for their documentation, and the results in the form of georeferenced side-scan sonar mosaics, bathymetric models or reconstructed photogrammetric models. It is important to mention that this was the first time that any of the selected sites were documented with sonar technologies or autonomous marine vehicles. The main objective of these surveys was to document and assess the current state of the sites and to establish a basis on which future monitoring operations could be built and compared. Beyond the mere documentation and physical preservation, examples of the use of these results for the digital preservation of the sites in augmented and virtual reality are presented.

Atlas of Shipwrecks in Inner Ionian Sea (Greece): A Remote Sensing Approach

Underwater cultural heritage (UCH) sites constitute an important part of the overall cultural heritage both nationally and globally as they carry cultural, environmental, scientific, technological, political, economic and social viewpoints. UCH includes not only submerged sites and buildings, but also vessels and aircrafts. The Inner Ionian Sea in Greece is a place rich in a significant number of shipwrecks with a timespan ranging from ancient times right through to the 20th century. The results herein present the study of ancient, World War I (WWI), World War II (WWII) and more recent shipwrecks in the inner Ionian Sea. A total of 11 out of 36 known shipwrecks in the area have been systematically studied using marine remote sensing and ground truthing techniques. The marine remote sensing sensors include: side scan sonars, sub-bottom profilers and multi-beam echo-sounders. At each wreck site, the condition of the wreck, the debris field and man-made activities were determined based mainly on acoustic data. The history of each wreck is also briefly documented. The conclusion of the current research work is that there is an immediate need for a shipwreck protection framework in the Inner Ionian Sea; wrecks included in this work are a highly important part of UCH and man-made activities (e.g., fishing) threaten their integrity.

A hybrid augmented reality guide for underwater cultural heritage sites

Modern technologies allow us to experience cultural heritage sites in new and exciting ways. Recent improvements in mobile computing provide tools capable of running augmented reality in real-time performance. Augmented reality is the perfect medium for visualizing and interacting with cultural heritage sites including both buildings and artefacts. Currently, this is possible on land, but sites located in the sea under water are hard to access and present many challenges. In this paper, we present a novel augmented reality guide for divers to present ancient lost buildings at underwater archeological sites. The prototype system runs on a smartphone sealed in a waterproof case and uses a hybrid approach (markers and inertial sensors) to localize the diver on the site. Accuracy of the tracker is measured in a laboratory in a simulated underwater environment. The application was experimentally evaluated at an underwater archeological site in Italy in Baiae. A pilot study with ten expert divers was performed, and their feedback, obtained directly in water, showed that this new experience significantly enhances user experience in underwater archeological sites.

Application of veratraldehyde as a temporary consolidant for relics at underwater cultural heritage sites

Because it is often difficult to preserve fragile relics in situ at underwater cultural heritage sites, it is sometimes necessary for relics to be extracted and moved to a controlled environment on land for protection and study. This paper discusses the feasibility of using the volatile organic compound veratraldehyde as a temporary consolidant for underwater fragile relics extraction. The results show that different materials (iron, tile, sand, wood) under water can be bonded together and extracted when using veratraldehyde. The fact that veratraldehyde is difficult to spread on the surface of underwater objects is a problem that can be solved by adding a layer of strong hydrophobic polypropylene (PP) fibres onto the object, serving as a ‘package' for the relics. Under laboratory conditions, we used veratraldehyde and PP fibres to extract broken tiles from underwater sand onto an exhibition stand. The broken tiles, in both condition and distribution, were safely and completely retained as the veratraldehyde was slowly removed by the soaking process. This work fills a gap in knowledge about temporary consolidant materials in underwater archaeology, and provides a new method for extracting underwater fragile cultural relics without damaging them.

A comparison of biodegradation caused by Teredinidae (Mollusca:Bivalvia), Limnoriidae (Crustacea:Isopoda), and C. terebans (Crustacea:Amphipoda) across 4 shipwreck sites in the English Channel

The need to protect underwater cultural heritage from biodegradation is paramount, however with many sites needing funding and support, it is hard to prioritise, thus the ability to identify high risk sites is crucial to ensure resources are best placed. In doing so a clear understanding of environmental conditions acting upon a site and abundance and composition of species present is essential to this identification. Therefore, the aim of this study was to assess the rate of biodegradation on four underwater cultural heritage sites in different marine environments by placing a series of wooden test panels in direct contact with the exposed structure on the sites. Upon recovery, test panels were photographed, X-rayed, and wood boring and sessile fouling species were identified and counted. The damage attributed to each species was recorded with CAD software. Results indicated a significant difference between sites, with HMS Invincible having the highest abundance of marine wood borers and the highest rate of surface area and volume degradation; whilst vestigial evidence of marine wood borers was found on the London, it would appear the environmental conditions had significantly impeded their survival. The study indicated further factors such as sediment type and coverage, availability of wood and the proximity of other colonised sites were also determining factors controlling the abundance of marine wood borers and the rate of biodegradation.

A Framework for Managing Diver Impacts on Historic Shipwrecks

Shipwrecks are becoming increasingly popular and, therefore important attractions for recreational scuba divers. Divers’ usage of these sites has the potential to create a range of adverse impacts on their cultural heritage values. Impacts associated with recreational scuba diving include boat anchor and mooring damage, impairment of site integrity and stability, the effects of intentional and unintentional contact with shipwrecks and artifacts, as well as divers’ exhaled air bubbles coming into contact with shipwrecks. While these consequences may not present a major threat in comparison to other human impacts, such as fishing activities, extractive industries or commercial salvage, their cumulative effect can be significant, particularly at sites where visitation levels are high. Unlike natural events such as storms, diver impacts can be controlled and managing these impacts is an important component of a heritage management strategy for any site. Heritage managers face the difficult challenge of, on the one hand, balancing divers’ access to important underwater cultural heritage sites, and on the other hand, protecting these sites. This paper outlines the causes and nature of potential recreational diver impacts on shipwrecks, briefly describing a range of management approaches that can mitigate such impacts, and presents a framework for the management of diver impacts on cultural heritage values of historic shipwrecks. The framework is designed to assist managers in deciding on appropriate management actions and priorities for particular sites.