Historic Shipwrecks Research Articles

A fuzzy evidential reasoning-based approach for assessing the navigation obstruction risk of shipwrecks in the Yangtze river

ABSTRACT This paper aims to evaluate the navigation obstruction risk represented by shipwrecks in shallow waters based on a fuzzy evidential reasoning approach. The purpose of this approach is to establish a hierarchical decision-making framework that considers ship conditions, traffic environment, distance from sensitive areas, and natural environment; to derive the belief rule base using the IF-THEN rule with a belief structure; and to obtain the crisp values of navigation obstruction risk of shipwrecks via evidential reasoning. This approach is applied to the navigation obstruction risk assessment of 10 historical shipwrecks in the Yangtze River, and the evaluation results are consistent with historical data. Consequently, this approach can be used for assisting in shipwreck salvage decision-making in navigable waters.

UNDERWATER CULTURAL HERITAGE AS A TOOL FOR IMPLEMENTING THE GLOBAL GOALS OF UN SUSTAINABLE DEVELOPMENT

The article analyses new approaches to respond to the challenges set out in the United Nations 2030 Agenda. The subject is relevant because seventeen Sustainable Development Goals are defined, which are a universal call to action for humanity to reduce poverty, overcome hunger, protect the planet and ensure that by 2030 all people live in peace and prosperity. According to the UNESCO Convention on the Protection of the Underwater Cultural Heritage (2001),sites that fall under its protection include archaeological remains of ships, historic structures, submerged landscapes, sunken cities, and ancient fishing structures. Such sites must have been underwater for at least 100 years. They must also be partially or completely, periodically or permanently submerged in the waters of the ocean, sea, lake or river. On the basis of analyzing the studies of foreign and domestic scientists, the author found out that with responsible use and management of underwater cultural heritage sites, it is possible to achieve effective methods of conservation and sustainable economic development of humanity. This is possible by increasing and accumulating knowledge of the oceans. In particular, stone tidal weirs, which are underwater cultural heritage sites, were investigated. Using these ancient structures for fishing today could be an effective solution to the problem of hunger. The study found that protecting underwater cultural heritage sites and the areas in which they are located ensures the conservation of marine resources. And this is one of the Sustainable Development Goals. The relationship between the protection of heritage sites and the prosperity of marine ecosystems helps to create livelihoods for local communities through dive tourism. Organizing underwater tourism at historic shipwreck sites can create new jobs. And this will lead to an increase in the welfare of the population. Quality management and responsible use of underwater heritage sites will lead to increased tourist flows. And this will contribute to the sustainable development of cities and communities. Thus, underwater cultural heritage is characterized by the integrity of cultural, natural, archaeological, tangible and intangible heritage. Such knowledge can be applied to solve the problems of our time. This makes heritage an important tool for achieving certain objectives of the Global Programme for Sustainable Development as defined in the United Nations 2030 Agenda.

Environmental Scanning Electron Microscopy of copper alloy artefacts from unidentified shipwreck sites: Clues to the identity of shipwrecks on Kenn Reef, Coral Sea

This study investigates the use of Environmental Scanning Electron Microscopes (ESEM) as a tool for identification of historic shipwrecks. Copper alloy fasteners from unidentified shipwreck on Kenn Reef in the Coral Sea, were sampled and analysed to determine the chemical composition of each artefact. When combining this data with known evolution of copper alloying for wooden ship construction, historical and archaeological data, the results provided valuable insight into the possible date range for these wrecks. Specifically, comparison to known wrecks in the vicinity of Kenn Reef could be linked to these previously unidentified sites. Results are promising and ESEM analyses proved to provide valuable, reliable data, yet also highlighted limitations and areas for further investigation and research.

Paleo-tropical cyclone activity over the last millennium inferred from shipwreck relics in the Xisha Islands, northern South China Sea

The prediction of the impact of long-term climate change on tropical cyclone (TC) activity has become a global concern, for which paleotempestology could provide crucial information about TC activity before instrumental archives. The ancient shipwrecks could alternatively be applied to retrieve paleo-TC activity owing to strong TC activity being among the dominant causes of historical shipwrecks. This study presents a preliminary study exploring the potential relationship between the shipwrecks and TC activity based on the compilation of shipwreck relics and chronological assessments of porcelains associated with the shipwrecks in the Xisha Islands, in the northern South China Sea (SCS). The compilation generally spans from the Song Dynasty to the Qing Dynasty (approximately 960 to 1850 CE), showing relatively enhanced shipwreck events during the time interval between 1400 and 1700 CE, consistent with the increased moisture and flood events during this period from other adjacent sedimentary records. Further analysis suggests that paleo-TC activity was controlled by multiple mechanisms concerning the El Niño Southern Oscillation (ENSO), the movement of the Intertropical Convergence Zone (ITCZ), and Asian dust emissions. Frequent ENSO events and the southward retreat of the ITCZ would have contributed to increased moisture in tropical regions promoting TC activity during the Little Ice Age (LIA), while the dust would strengthen TC activity through atmospheric circulations. Additional work combining the archaeological and sedimentary archives should be indispensable to further understand the climatic connections and potential mechanisms of TC processes, under climate change and relevant mitigation measures.

Substrate Specificity of Biofilms Proximate to Historic Shipwrecks.

The number of built structures on the seabed, such as shipwrecks, energy platforms, and pipelines, is increasing in coastal and offshore regions. These structures, typically composed of steel or wood, are substrates for microbial attachment and biofilm formation. The success of biofilm growth depends on substrate characteristics and local environmental conditions, though it is unclear which feature is dominant in shaping biofilm microbiomes. The goal of this study was to understand the substrate- and site-specific impacts of built structures on short-term biofilm composition and functional potential. Seafloor experiments were conducted wherein steel and wood surfaces were deployed for four months at distances extending up to 115 m away from three historic (>50 years old) shipwrecks in the Gulf of Mexico. DNA from biofilms on the steel and wood was extracted, and metagenomes were sequenced on an Illumina NextSeq. A bioinformatics analysis revealed that the taxonomic composition was significantly different between substrates and sites, with substrate being the primary determining factor. Regardless of site, the steel biofilms had a higher abundance of genes related to biofilm formation, and sulfur, iron, and nitrogen cycling, while the wood biofilms showed a higher abundance of manganese cycling and methanol oxidation genes. This study demonstrates how substrate composition shapes biofilm microbiomes and suggests that marine biofilms may contribute to nutrient cycling at depth. Analyzing the marine biofilm microbiome provides insight into the ecological impact of anthropogenic structures on the seabed.

Performance Space and Stage Technologies: A Comparative Perspective on Theatre History ed. by Nawata Yuji and Hans Joachim Dethlefs

Reviewed by: Performance Space and Stage Technologies: A Comparative Perspective on Theatre History ed. by Nawata Yuji and Hans Joachim Dethlefs Pascale Aebischer (bio) Performance Space and Stage Technologies: A Comparative Perspective on Theatre History Edited by Nawata Yuji and Hans Joachim Dethlefs. Bielefeld: transcript Verlag, 2022. Pp. 176. Nawata Yuji and Hans Joachim Dethlefs's edited collection arises from "Towards a Global History of Culture," a research project based at Chuo University in Tokyo. In March 2020, the project was forced to pivot from in-person exchanges at a symposium to the alternative format of this volume. Consequently, until the final chapter in which Nawata seeks to offer categorizations and sketch out the global circulation of "cultural techniques," the book offers a starting point for comparison rather than an overarching comparative argument. As someone trained in early modern studies, I found Ishida Yuichi's analysis of the role of central perspective in Catholic churches (with a focus on Italy) particularly illuminating: the discussion of altar pieces and how they related to theatrical set designs and the creation of a "theatrum sacrum" as a place for seeing God's miracles struck me as an important context for understanding the connection between spiritual values and perspectival set designs in secular performance spaces. This was also one of the few chapters that seemed to pick up implicitly, if not explicitly, on another contribution to the volume: preceded, as it is, by Dethlefs's chapter on the early modern German reception of Vitruvius's and Serlio's architectural tracts regarding theatre design, Ishida's argument seemed to offer a possible answer to why Walter Hermann Ryff (the subject of Dethlefs's contribution) was so suspicious of perspectival design in the theatre. That comparative connection, however, is never actually articulated within the volume and it is the reader who has to do the work of joining the dots. Other chapters open up windows into fields, periods, and cultures with which I had little prior acquaintance: Seo Tatsuiko's essay on the theatrical elements of a Chinese novel, The Tale of Li Wa, set in Tang dynasty (ninth century) Chang'an, intricately maps the urban landscape of the novel before, in a surprise twist, suggesting that there is a global "four quadrant structure of love drama" that is "universal." Mitsuma Yasuyuki's consideration of semicircular theatre in ancient Babylon springs a similar surprise in the sudden turn from a scene analysis of the presentation of Crassus's head to the reading out of letters. However, there is little in this chapter to link it either to stage technologies or the semicircularity of the theatre advertised in the title. Three chapters focused on entertainment culture leading up to and around the turn of the twentieth century are connected by little more than rough simultaneity: Hioki Takayuki's investigation of stage machinery and special effects in Kabuki theatre is fascinating in the detailed insight it affords [End Page 588] into the staging of historical shipwrecks. It is worlds apart from Itoda Soichiro's investigation of the legislation that changed what could be defined as "theatre" in Berlin between 1870 and 1890 and, consequently, the expansion and subsequent decline of the theatre industry in the German capital. The section closes with Enomoto Yosuko's exploration of the Lyceum Theatre in Shanghai and its role in "expressing to the Chinese what Western art was" (p. 125). The book's final section contains two essays alongside Nawata's conclusion. Ito Masaru's essay on the Leningrad School's approach to theatre spaces is concerned exclusively with the theoretical writing in the 1920s of A. Gvozdev, the head of the Department of Theatre History at the Institute of Art History in Leningrad. Kai Van Eikels's discussion of projection technology stretches from Piscator via Peter Brook to the more recent work of Robert Lepage, the Japanese collective Dumb Type, and Frank Castorf's staging of Erniedrigte und Beleidigte in 2001, in which video projections of actors who remained inaccessible to the audience frustrated the audience's desire to see the actors' "laboring-for-the-audience" (p. 155). The book thus offers an eclectic selection of essays that offer valuable insights into...

Combining Historical, Remote-Sensing, and Photogrammetric Data to Estimate the Wreck Site of the USS Kearsarge

Colombia has hundreds of historical shipwrecks, but systematic research on this topic is scarce, which makes locating wreck sites problematic. Colombia is home to the Caribbean archipelago of San Andres, Old Providence, and Santa Catalina. Its complex environmental conditions make it a “ship trap”. On 2 February 1894, the USS Kearsarge ran aground on Roncador Cay, one of the Archipelago’s islets, and the location of the wreck site remains uncertain. Due to its role in the American Civil War, the Kearsarge is important naval heritage. Based on historical and cartographic records, orthophotographs, Landsat images, and light-detection-and-ranging (LiDAR) data, this study aimed to estimate the location of the wreck site in a Geographic Information System (GIS). Court-martial records, particularly nautical data and astronomical coordinates, were reviewed, including a study from 1894 indicating the wreck’s location on a map without coordinates. Nautical charts were also analyzed to find the Kearsarge wreck symbol. To identify the wreck site’s ordnance, logbooks and information on previous salvage efforts were examined. The analysis of nautical charts revealed a few shipwrecks, but not the Kearsarge. Historical and remote-sensing data were processed in a GIS, along with the most recent nautical chart of Roncador Cay from 2017, to obtain a possible geographical location. This resulted in coordinates, which were used to detect features associated with the USS Kearsarge in the processed data. Although the wreck was not detected, the data helped to estimate the approximate coordinates for where the wreck could be located, quantifying our degree of uncertainty.

80 years later: Marine sediments still influenced by an old war ship

Historic shipwrecks form an anthropogenic landmark in marine environment, yet their influence on the local geochemistry and microbiology remains largely unexplored. In this study, sediment and steel hull samples were taken around the V-1302 John Mahn, a World War II shipwreck, at increasing distance from the wreck, in different directions. Polycyclic aromatic hydrocarbons (PAH’s), explosives, and heavy metal levels were determined and related to the microbial composition. Benz(a)anthracene and fluoranthene remain present at the mg kg-1 level, probably originating from the coal bunker. These PAH’s indicate that the wreck is still influencing the surrounding sediments however the effects are very dependent on which side of the wreck is being studied. Known PAH degrading taxa like Rhodobacteraceae and Chromatiaceae were more abundant in samples with high aromatic pollutant content. Moreover, sulphate reducing bacteria (such as Desulfobulbia), proven to be involved in steel corrosion, were found present in the biofilm. This study shows that even after 80 years, a historic shipwreck can still significantly steer the surrounding sediment chemistry and microbial ecology.

Intuitively visualizing spatial data from biogeographic assessments: A 3-dimensional case study on remotely sensing historic shipwrecks and associated marine life

Biogeographic assessments aim to determine spatial and temporal distributions of organisms and habitats to help inform resource management decisions. In marine systems, rapid technological advances in sensors employed for biogeographic assessments allow scientists to collect unprecedented volumes of data, yet it remains challenging to visually and intuitively convey these sometimes massive spatial or temporal data as actionable information in geographically relevant maps or virtual models. Here, we provide a case study demonstrating an approach to bridge this data visualization gap by displaying coastal ocean data in a 3D, interactive online format. Our case study documents a workflow that provides resource managers, stakeholders, and the general public with a platform for direct exploration of and interaction with 3D data from hydrographically mapping shipwrecks and marine life on the continental shelf of North Carolina, USA. We simultaneously mapped shipwrecks and their associated fish using echosounders. A multibeam echosounder collected high-resolution multibeam bathymetry of the shipwrecks and detected the broad extent of fish schools. A calibrated splitbeam echosounder detected individual fish and fish schools. After processing the echosounder data, we built an interactive, online 3D data visualization web application complemented by multimedia and story text using ESRI geographic information systems. The freely available visual environment, called “Living Shipwrecks 3D,” allows direct engagement with the biogeographic assessment data in a customizable format. We anticipate that additional interactive 3D data applications can be constructed using a similar workflow allowing seamless exploration of complex spatial data used in biogeographic assessments.

The Australian Management of Protected Underwater Cultural Heritage Artifacts in Public and Private Custody

AbstractThis article briefly outlines underwater cultural heritage artifact management in Australia from an unregulated collecting environment in the 1940s–1960s to the increasingly regulated environment of the present. In 1993, in conjunction with new legislation, an amnesty was declared in order to inventory artifacts collected from now-protected historic shipwrecks that were in private hands. The amnesty period concluded with approximately 20,000 artifacts notified at a time when information was being stored in a range of formats and to different standards. Today, the Australian Government manages the possession, custody, and control of approximately 500,000 underwater cultural heritage artifacts, most of which are in collecting institutions, with one-tenth in public custody. This article highlights the contemporary legislative, policy, and administrative framework for the management of underwater cultural heritage artifacts in Australia, particularly those that remain in the possession of private individuals and are subject to trade.

Queen Anne’s Revenge Coal Conundrum: Origins of Coal Found in Association with a Historic Shipwreck

<i>Queen Anne’s Revenge</i> Coal Conundrum: Origins of Coal Found in Association with a Historic Shipwreck

Historic Wooden Shipwrecks Influence Dispersal of Deep-Sea Biofilms

Wood arrives on the seabed from natural and anthropogenic sources (e.g., wood falls and wooden shipwrecks, respectively) and creates seafloor habitats for macro-, meio- and microbiota. The way these habitats shape microbial communities and their biogeographic patterns in the deep sea requires study. The objective of this work was to investigate how historic wooden-hulled shipwrecks impact the dispersal of wood-colonizing microbial biofilms. The study addressed how proximity to wooden shipwrecks shapes diversity, richness, and community composition in the surrounding environment. Study sites included two historic shipwrecks in the northern Gulf of Mexico identified as wooden-hulled sailing vessels dating to the late 19th century. Two experimental microbial recruitment arrays containing pine and oak samples were deployed by remotely operated vehicle proximate (0–200 m) to each shipwreck and used to establish new wooden habitat features to be colonized by biofilms. The experiments remained in place for approximately 4 months, were subsequently recovered, and biofilms were analyzed using 16S rRNA gene amplification and sequencing for bacteria and archaea and ITS2 region amplification and sequencing for fungi to determine alpha diversity metrics and community composition. The work examined the influence of wood type, proximity to shipwrecks, and environmental context on the biofilms formed on the surfaces. Wood type was the most significant feature shaping bacterial composition, but not archaeal or fungal composition. Proximity to shipwrecks was also a significant influence on bacterial and archaeal composition and alpha diversity, but not on fungal communities. In all 3 domains, a peak in alpha diversity and richness was observed on pine and oak samples placed ~125 m from the shipwrecks. This peak may be evidence of an ecotone, or convergence zone, between the shipwreck influenced seabed and the surrounding seafloor. This study provides evidence that historic wooden shipwrecks influence microbial biofilm dispersal in the deep sea.

Shipwrecks are not the ultimate attracting features in a natural marine environment-the case of Karaburun, Turkey

Shipwrecks attract divers. Therefore, decommissioned marine vehicles are used as artificial reefs for recreational diving tourism around the world. We examined divers' attitudes towards shipwrecks and their function as an ecological enhancers. The study was carried out in the Karaburun Peninsula, Turkey, where two passenger ships were sunk as artificial wreck reefs to attract diving tourism. Using a questionnaire survey accompanied by face-to-face interviews, of both certified divers and non-certified discovery divers we collected information about divers reefs preferences, perception of artificial reefs as well as their socio-demographic characteristics, dive experiences etc. Differences in divers’ wreck (historical or artificial) and reef preferences (natural reefs or artificial wrecks) were analyzed with the Mann-Whitney U test. Overall, divers held the position that artificial wreck reefs provide ecological benefits on fish diversity and stocks (p < 0.05), and experienced divers supported this position more that novice ones. However, experience and number of annual dives did not affect this notion. Non-certified respondents were mostly neutral towards the ecologic and management statements. However, the majority of divers (84%) preferred to dive on natural reefs rather than on shipwrecks. Similarly, most of them (83%) preferred diving to historical shipwrecks which sank in wars or accidents, and not on ships intentionally sunk as attractions. These findings, which are in line with previous literature, put a question mark on the growing practice of sinking nearly any ship to create diving attractions.

Structural factors driving benthic invertebrate community structure on historical shipwrecks in a large North Atlantic marine sanctuary

Shipwrecks are irreplaceable historical resources and valuable biological habitats. Understanding the environmental and anthropogenic factors affecting shipwrecks is critical for preservation in situ. We used remotely operated vehicles to study the benthic invertebrate communities on four shipwrecks in Stellwagen Bank National Marine Sanctuary (SBNMS, North Atlantic, USA). Shipwrecks included coal schooners and a passenger steamer, all >100 years old. These large, complex structures hosted dense populations of invertebrates (34 species), especially on high-relief and overhanging substrata. Some species that are otherwise rare in the community may proliferate through asexual reproduction and form dense populations on shipwrecks. We also investigated impacts of entangled fishing gear on the invertebrate communities on each shipwreck and found that areas with the most ghost gear have lower species richness and different community structure. Fishing, particularly bottom trawling, damages shipwrecks and poses a threat to these valuable cultural resources and biological habitats in SBNMS.

Bone diagenesis in the marine environment‐I: Characterization and distribution of trace elements in terrestrial mammalian bones recovered from historic shipwrecks

AbstractUnlike the chemical composition and diagenetic modification of buried bones, subaqueous archaeological bone diagenesis has not been studied in detail. This observational work presents a macroscopic and microscopic characterization of 11 variably preserved archaeological terrestrial mammalian bones submerged in seawater and/or surrounded by marine sediment for 169–347 years. In situ trace element analysis was undertaken to identify geochemical fingerprints of diagenesis. The analyzed bones belong to a collection of underwater archaeological faunal materials excavated from four shipwreck sites. With one exception, all archaeological bones were fragmented, some were also heavily stained, and in two samples, the damage to the cortical layer was extensive. Bioerosion was assessed by scanning electron microscopy (SEM), and bone trace element chemistry (by laser ablation inductively coupled mass spectrometry—LA‐ICP‐MS) was compared with that of an unsubmerged modern sheep bone control. In the control, several trace elements were low in concentration (weighted mean concentration &lt;1 ppm; Cr, Co, Ni, Cu, Y, rare earth elements, Th, U). In the submerged archaeological bones, the weighted mean concentration of Li, Cr, Cu, and U was enriched relative to the modern sheep bone, whereas Rb and Ba were depleted. The best‐preserved bone, recovered from Batavia, showed less variation in trace element patterns compared with the more poorly preserved bones. The only archaeological bone with preserved macroscopic structure and cortex showed a gradual decrease in trace element concentration from the outer surface towards the medullary cavity, whereas in samples where more cortical damage was noted, the distribution of these elements is more irregular. With the exception of Cu and Cr, the elements focused on in this work (Li, U, Rb, and Ba) are nonessential to life, supported by their low concentration in the modern sheep bone (with the exception of Ba). The results suggest that early macroscopic and microscopic diagenetic alteration influences the concentration and distribution of chemical elements in submerged bones and that in situ trace element analysis provides clues for the reconstruction of taphonomic trajectories.

Study of the Historic Shipwreck Sites Area Development for Marine Ecotourism in Thousand Islands

The historic shipwreck sites are a part of the Maritime Archaeological Resources. They are currently occupying an important position as one of the non-conventional marine resources with blue economy potential in it. Sites are usually found in the conditions that have been integrated with the marine ecosystem in their environment. Some have even been completely covered with coral reefs, so that this uniqueness becomes the added value of the site for a tourist attraction. The research was carried out in Thousand Islands waters, which having kept many records of the maritime history of the Nusantara Archipelago for centuries and in their current development, the Jakarta∧s Thousand Islands are included as one of the Marine Tourism Village areas (Desa Wisata Bahari/Dewi Bahari). The purpose of this research is to determine the value of the shipwreck sites potency which are suitable for marine ecotourism development area in Thousand Islands waters and for obtaining the sustainable management model that can be integrated with the ecosystem in their environment. The research methods used sites surveys, focus group discussions, and interviews. Data processing was done by using Site Significance Assessment analysis. The result shows there are 4 (four) of historic shipwreck sites potency area in Thousand Islands waters which can be recommended as the attraction for marine ecotourism with the model of the Marine Eco Archaeological Park (MEA Park). These sites areas include 1)Shinta wreck in Pari Island waters, 2) Tabularasa wreck in Pramuka Island waters, 3) Poso wreck in Karang Congkak waters, and 4) Papatheo wreck in Sepa Island waters.

Diving Deeper into Wreck Diver Motivations and Attitudes

Increased demand by dive tourists for high-quality underwater wreck sites requires managers to balance heritage conservation and tourism at these vulnerable sites to ensure quality diving experiences while protecting underwater cultural heritage. Integral to effective management is a comprehensive understanding of wreck diver characteristics, motivations, and attitudes. This paper reports the outcomes of an international survey of 724 wreck divers including demographics, dive experience, motivations to wreck dive and attitudes to underwater cultural heritage protection. Wreck divers are motivated to see historic shipwrecks, artefacts, and marine life. Most are generally supportive of management controls to protect underwater cultural heritage. Conceptual models of wreck divers’ motivations and attitudes were developed to illustrate nuanced complexities in motivations and attitudes, which can inform management strategies to support operational decisions and destination marketing.

Deep-sea shipwrecks represent island-like ecosystems for marine microbiomes

Biogeography of macro- and micro-organisms in the deep sea is, in part, shaped by naturally occurring heterogeneous habitat features of geological and biological origin such as seeps, vents, seamounts, whale and wood-falls. Artificial features including shipwrecks and energy infrastructure shape the biogeographic patterns of macro-organisms; how they influence microorganisms is unclear. Shipwrecks may function as islands of biodiversity for microbiomes, creating a patchwork of habitats with influence radiating out into the seabed. Here we show microbiome richness and diversity increase as a function of proximity to the historic deep-sea shipwreck Anona in the Gulf of Mexico. Diversity and richness extinction plots provide evidence of an island effect on microbiomes. A halo of core taxa on the seabed was observed up to 200 m away from the wreck indicative of the transition zone from shipwreck habitat to the surrounding environment. Transition zones around natural habitat features are often small in area compared to what was observed at Anona indicating shipwrecks may exert a large sphere of influence on seabed microbiomes. Historic shipwrecks are abundant, isolated habitats with global distribution, providing a means to explore contemporary processes shaping biogeography on the seafloor. This work is a case study for how built environments impact microbial biodiversity and provides new information on how arrival of material to the seafloor shapes benthic microbiomes.

Sacralization in the Mary Rose and Kronan assemblages: An inconsistently recorded anomaly

AbstractThis study aims to promote consistent observations of sacralization, a relatively common form of lumbosacral transitional vertebrae (LSTV). Sacralization can inform on genetic affiliation. There are four types, ranging from enlarged transverse processes to bony ankylosis. Complete sacralization reportedly occurs in 1.5%–14% of archeological and modern populations, yet clinical studies can conflate types, resulting in rates as high as 46%. Archeologically obtained sacra and lower lumbar vertebrae from two historical shipwrecks (16th century English warship Mary Rose and 17th century Swedish warship Kronan) are compared via gross observation. These semi‐documented individuals, fit enough to be on a warship during battle, have a documented cause, manner, and date of death. The assemblages yield 120 sacra; complete sacralization is compared between the crews. Both crude and true prevalence of bony ankyloses are recorded with χ2 analyses testing significance. Both samples have 16.7% true prevalence of complete sacralization, with 38.3% of Mary Rose sacra and 26.7% of Kronan sacra showing some variant of LSTV. It is possible the high rates of sacralization shown in both crews are related to the samples being drawn from similar populations: a Swedish clinical study finds a similar rate of 13.9% for “complete” sacralization. However, reported rates of less than 1.0% in other archeological samples suggest that true sacralization is inconsistently recognized. Finally, clinical and archeological studies either conflate all types or fail to state their diagnostic criteria, reducing the ability to accurately compare findings.

Analysis of Water Quality in Historical Shipwreck Sites to Support the Development of Marine Ecotourism in the Thousand Islands

Thousand Islands has become the main focus of the marine tourism development in Special Capitol Region of Jakarta (DKI Jakarta). In this regard, one of the marine tourism objects proposed to be further developed is historical shipwreck diving as a new marine ecotourism attraction in the Thousand Islands. The historical sites of shipwrecks that are widely scattered underwater are expected to give added value to the beauty of underwater panorama because most of the sites have been covered with coral reefs adding to the uniqueness to the underwater diving attractions. However, the high activity on the North Coast of Java area and surrounding islands tends to affect the water quality and the presence of shipwrecks assuming it will be used for the development of diving tourism. This study aims to determine the carrying capacity of water quality on shipwrecks based on in situ water quality measurement and image analysis. The method of data collection and analysis carried out is a combination of in situ measurements at the location; analysis of water samples with laboratory testing and analysis of Landsat 8 satellite imagery. The result showed that nutrient and orthophosphate values of nitrate, which supported the life of marine biota and micro-algae that helped the biota’s biofouling process, increased the site’s attractiveness from 0.094 – 0.101 mg/L and 0.005 – 0.008 mg/L, respectively. Furthermore, other water quality values measured are still in accordance with quality standards for marine life survival on shipwrecks and ecotourism, especially dive spots with clear water visibility.