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Title A name given to the resource The Periplus Maris Erythraei Creator An entity primarily responsible for making the resource Casson, Lionel Publisher An entity responsible for making the resource available Princeton University Press Date A point or period of time associated with an event in the lifecycle of the resource 1989 Type The nature or genre of the resource Book Zotero Translator Casson, Lionel Item Type Book Date A point or period of time associated with an event in the lifecycle of the resource 1989 Place Princeton, N.J Publisher An entity responsible for making the resource available Princeton University Press Title A name given to the resource The Periplus Maris Erythraei Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource New Light on Maritime Loans: PVindob.G 40882 Creator An entity primarily responsible for making the resource Casson, Lionel Date A point or period of time associated with an event in the lifecycle of the resource 1990 Type The nature or genre of the resource Journal Article Zotero Author Casson, Lionel Item Type Journal Article Date A point or period of time associated with an event in the lifecycle of the resource 1990 Pages 195-206 Publication Title Zeitschrift für Papyrologie und Epigraphik Title A name given to the resource New Light on Maritime Loans: PVindob.G 40882 Volume 84 https://apconf-much.org/proceedings/files/original/13c4043d24fd8aa226688a96e05d2248.pdf 20904f40b57b3fb135f8541dcd0715fa PDF Text Text The Maritime Cultural Landscape of the Port of San Jacinto and the galleon shipwrecks in Ticao Pass, Central Philippines Catherine E. Villamor (Graduate student, University of the Philippines, School of Archaeology) ABSTRACT During the Spanish colonial period, European explorers noted that Ticao Island in the Central Philippines was the source of water, wood, and other galleon provisions. Hence, the Port of San Jacinto in Ticao was one of the last ports the galleons touched before sailing into the Pacific, and vice versa. Ticao Pass is the graveyard of galleons such as Encarnación (1649) and Santo Cristo de Burgos (1726) to the east of the island. Through the years, local histories have been written about the island's glorious past as a galleon port. However, only a little archaeology has been done on this subject. Thus, this study aims to report the status of the archaeological research on Ticao’s role in the galleon trade. This paper charts relevant historical sites, i.e., potential archaeological sites, for future reconnaissance. The resources available to conduct the work include ethnohistorical data, archival maps, maritime charts, archaeological reports, site discovery forms, and artefacts. These resources are deemed ample to illustrate the maritime cultural landscape of the Port of San Jacinto, the underwater archaeology of the galleon shipwrecks in Ticao Pass, and the lasting impact of galleon trade in the island, especially in the town of San Jacinto. Keywords: Ticao, Port of San Jacinto, galleon trade, galleon shipwrecks List of Figures Figure 1. Locational map of San Jacinto, Ticao Island and Ticao Pass - Murillo-Velarde map (1734) Figure 2. The location of the galleon shipwrecks in Ticao Pass Figure 3. Maritime Cultural Landscape of Port San Jacinto Manila-Acapulco Galleon Trade (1565-1815) Figure 4. a. Reproduction of Cosme Bertodano’s Plano de el Puerto de San Jacinto (1792); b—Plan & View of St. Jacinto on Ticao (1763); and c. Plano de el Puerto de San Jacinto (1792) INTRODUCTION The history of Ticao Island in Central Philippines (Figure 1) is primarily intertwined with maritime traditions. In the Spanish colonial period, Ticao Pass was part of the treacherous route of the ManilaAcapulco Galleon Trade (1565-1812 CE) known as the Embocadero or the Paso de Acapulco (Schurz 1939). So, the Port of San Jacinto on this island ‘was celebrated for it served as a harbour for the famed galleons’ (Montero 1886, 338). It was also the source of water and wood; thus, it was the last port the galleons touched before sailing to the Pacific (Careri 1983). This paper investigates the extent of archaeological research on the role of Ticao Island and Ticao Pass in the Manila-Acapulco Galleon Trade. It reviews the underwater archaeology done on the galleon shipwrecks in Ticao Pass. The study also illustrates the maritime cultural landscape of the galleon port of San Jacinto from archival maps, nautical charts, and ethnohistorical accounts, which could be investigated archaeologically. Ultimately, this work discusses the lasting impact of the galleon trade on Ticao Island, especially in San Jacinto. 1 �Figure 1. Locational map of San Jacinto, Ticao Island and Ticao Pass [Satellite image: ESRI World Imagery] in relation to the route of Manila-Acapulco Galleon Trade as shown in the Murillo-Velarde map (1734), the overview map on this figure [Source: Library of Congress] METHODS Library and archival research were conducted to gather historical and archaeological data that are relevant to the roles of Ticao in the Manila-Acapulco Galleon Trade. This research also involves georeferencing archival maps published from 1565 to 1815 and geotagging relevant placenames and spatial references from ethnohistorical accounts using QGIS version 3.28.2. Some ethnohistorical 2 �sources are not directly linked to the galleon trade but apply to the maritime traditions in Ticao Island within its period, such as indigenous warfare, sea piracy, and slave raiding. RESULTS AND DISCUSSION According to Schurz (1939), from Cavite on Manila Bay, the galleons passed through the Embocadero towards San Bernardino Strait. However, storms would often coincide with the voyage, hence ‘galleons were… frequently becalmed for days’ (La Follette and Deur 2018, 169) and were ‘always delayed at San Jacinto on Ticao, or some other port in the vicinity’ (Schurz 1939, 222). The Galleon Shipwrecks in Ticao Pass Since Ticao Pass is part of the galleon trade route, it became the graveyard of galleons and other vessels during the Spanish colonial period. Some of the galleons that were wrecked in this passage were Nuestra Señora de la Encarnación (1649 CE), Santo Cristo de Burgos (1726 CE), San Cristóbal (1733 CE), Magallanes (1793 CE), and San Andrés (1798 CE) (Philippine Commission of Independence 1923; Schurz 1939; Warren 2012) (Figure 2). In the past thirty years, at least two of those galleons have been investigated archaeologically, namely Nuestra Señora de la Encarnación (1649 CE) and Santo Cristo de Burgos (1726 CE). Jago-on and Orillaneda first discussed the investigations of Encarnación and Santo Cristo de Burgos in the essay ‘Archaeological Researches on the Manila Galleon Wrecks in the Philippines’ (2019). Encarnación On its way to Manila, on 5 October 1649, Nuestra Señora de la Encarnación was struck by a typhoon near Bulan, Sorsogon. This maritime tragedy is attributed to Encarnación’s late departure from Acapulco. Two hundred passengers died, and all its cargo was sunk along with the galleon (Warren 2012, 195). On 28 November to 10 December 1985, the National Museum of the Philippines investigated the possible wreck of Encarnación. According to them, it was located approximately 1.5 kilometres westnorthwest of Bulan. Their team could not recover the ceramics and other cargoes of the galleons. On the other hand, they found ‘the double wall sidings of a wooden ship, the base of its mast, a probable cannon with heavy encrustations and a large piece of heavily rusted iron’ (Cuevas 1985, 1). An archaeological excavation was conducted from 28 December 1985 to 22 January 1986, where the team exposed wooden planks and ballast stones. However, due to strong currents, the team ceased the excavations ‘temporarily’ for their safety (Malones 1986, 1-2). Based on the available records, the wreck of Encarnación has not been re-excavated since then. 3 �Figure 2. The location of the galleon shipwrecks in Ticao Pass Santo Cristo de Burgos The Acapulco-bound Santo Cristo de Burgos was hit by a typhoon near the shores of Ticao Island on 23 July 1726 CE. The galleon was described as a ‘500-ton fully laden vessel with a valuable cargo and unspecified number of passengers and more than 250 sailors. The only casualty of this tragedy was the ship’s master of the galley (Fish 2011, 508). However, while the, ‘crew and the passengers escaped… the cargo was mysteriously burned’ (Schurz 1939). Therefore, this maritime disaster underwent severe scrutiny from the Spanish authorities, who received tons of charges from aggrieved merchants (Schurz 1939, 260). They discovered that the galleon sunk during the storm because it was not anchored in its usual anchorage in the Port of San Jacinto. In October 1726 CE, the investigation committee concluded that the captain, chief pilot, and six officers were guilty of the loss of the galleon and its cargo. They were imprisoned, and the government seized their properties to compensate the aggrieved parties (Fish 2011). The National Museum of the Philippines surveyed the possible Santo Cristo de Burgos wreck site in July 1985. This underwater survey was mentioned and charted by Conese in the article ‘Underwater Archaeology in the Philippines’ (1989). The wreck, first discovered by a fisherman, is about 4.5 kilometres north of the Port of San Jacinto. Based on the survey form, they recovered tradeware sherds, earthenware sherds, and glass bottle pieces. Three anchors were also taken ashore, one of which was 15 feet long. From April to May 2004, the Far Eastern Foundation for Nautical Archaeology, Inc. (FEFNA) launched the Santo Cristo Archaeological Exploration Project in San Fernando, approximately 10 kilometres south of the Port of San Jacinto. The artefacts recovered included an iron ring, a shell artefact, and ceramics (Alba 2004). It is important to note that the area FEFNA explored is about 14 kilometres from the San Jacinto Wreck Site. Moreover, the report for this exploration project did not reference the San Jacinto Wreck Site, which was first considered as the possible wreck site of Santo Cristo de Burgos. 4 �The Maritime Cultural Landscape of the Galleon Port of San Jacinto Figure 3. The Maritime Cultural Landscape of the Port of San Jacinto during the Manila-Acapulco Galleon Trade (1565-1815 CE) According to Westerdahl (2011, 735), ‘The occurrence of historic shipwrecks must have relied on a logistic network of the past which could be recorded in the same process’. Currently, the galleon port of San Jacinto has not been investigated archaeologically. Hence, archival maps and ethnohistorical accounts were reviewed to illustrate its maritime cultural landscape during the Manila-Acapulco Galleon Trade. Westerdahl (1992, 6) defines maritime cultural landscape as ‘the whole network of sailing routes, old as well as new, with ports and harbours along the coast, and its related constructions and remains of human activity, underwater as well as terrestrial’. In the Port of San Jacinto, this network includes places that are relevant to maritime activities (e.g., trade, shipbuilding, and piracy), such as sources of provisions, docks, ports, shipyards, and fortifications (Figure 3). These landmarks were geotagged based on the Bertodano 1792 CE map (Figure 4a) and ethnohistorical sources. In the late 1600s, Italian adventurer Gemelli Careri notes in his travel accounts that San Jacinto was a ‘good port with the conveniency of fresh water and wood and is, therefore, the last land the ships bound for New Spain touch at’ (Careri 1983, 42). Based on the Dalrymple 1763 CE map (Figure 4b) and the notes on the Bertodano 1792 CE map (Figure 4c), the most accessible source of freshwater for the vessels (such as the galleons) was the river northeast of the Punta de Bodega called Aguada. The other sources were the tributaries of the Estero de Santa Rosa. There were also two wells on both sides of the bay. 5 �Figure 4. a. Reproduction of the Cosme Bertodano’s Plano de el Puerto de San Jacinto (1792) by Príncipe de la Paz; b. Plan & View of St. Jacinto on Ticao (1763) by Alexander Dalrymple; and c. Plano de el Puerto de San Jacinto (1792) by Cosme Bertodano [Sources: Biblioteca Nacional de España and Archivo Museo Naval de Madrid] 6 �On the other hand, the wood was probably acquired from the ‘hillocky’ cove on both sides of the anchorage (See Figure 3b). In particular, the Patag, east of Población, was the area where hardwoods such as Ipil (Intsia bijuga), Barayong (Afzelia rhomboidea), and Hamorawon (Vitex parviflora) were sourced during the Spanish colonial period (Merillo 1981). Due to its proximity to the port, it was probably also the source of wood for the galleons. In addition, along the Port of San Jacinto, there were places relevant to the prosaic maritime activities. To the east of the Punta de San Juan was a ‘historical beach’ where small indigenous watercraft such as banca (small dugout boat) and cumpit (fishing vessel) docked. In addition, based on the local history, Sitio Fabrica near Rondajan was a dockyard for bancas and ships (Merillo 1981). Interestingly, the Real Astillero de Mobo on the island of Masbate was located at Barangay Fabrica (Non 1993; Pelorina 2015). It is important to note that in the Spanish colonial period, ships and other vessels were built in the Philippine archipelago to facilitate fishing, transportation, and trade and were instrumental in fighting against sea pirates and slave raiders (Non 1993). In San Jacinto, inhabitants ‘rode small bancas pretending to be fishing within the town's bay and outside the bay's mouth, which would distract the entrance of sea pirates’ (Merillo 1981, 45). A round-the-clock patrol was also done on land in Rondajan, and because of the rampant piracy, ‘In 1701 a formal union of the settlers was formed with the end in view to protect themselves from the Moro marauders’ (Almodal 1953, 2). This marked the birth of the Población (settlement) in the Port of San Jacinto. Aside from building houses, the inhabitants built ‘more and better fortifications’ (Almodal 1953, 2). Cannons were installed in several areas, such as the Garita Rock (Spanish for ‘sentry box’), the Bagalayag Rock (probably near the Punta de Bodega), and the Binantayan Rock (also known as Binantayan Point) (Merillo 1981). Watch posts (vernacular: bantai/bantay/bantayan) were also established in strategic points such as the Punta de Tajiran, Punta de Binantayan, and Punta Lagan. Moreover, two watch posts were installed on Bantayan hills. There, the sentinels would blow their balalong (hollowed tree trunk) or bodiong (carabao horn or conch) to warn the inhabitants of the incoming raiders (Morado 1953; Barrun 1953; Mallari 1989). More importantly, guards were assigned to the fortress and the church, which served as the primary refuge for the inhabitants amidst intrusions (Merillo 1981). These defence structures protected the inhabitants from the indigenous sea pirates but also against Dutch and British intruders. In 1646 CE, the bay of San Jacinto was the venue of one of the skirmishes of the Battle of La Naval de Manila between the Spanish fleet and the Dutch squadron. On 22 June 1646 CE, a sentinel reported seven Dutch warships approaching the waters of San Jacinto. A day later, the Dutch forces attempted to seize the Garita Rock to ambush two galleons. However, they were vanquished by the local and Spanish forces. As a result, the Dutch seized the Port of San Jacinto until 24 July 1646 CE. More than a century later, during the British Occupation of Manila (1762-1764 CE), one of the ships of the British fleet attempted to anchor in the Port of San Jacinto but received cannon fire from the fortress. On 20 December 1797 CE, the inhabitants of the Población fled after they were warned of the atrocities of some British entities. These intruders were demanding foodstuffs, cattle, and freshwater. When the Spanish and local authorities refused to give in, the intruders fired at the church with ammunition before finally leaving the port (Gerona 2012). The other ports in Ticao Island during the galleon trade Based on the Murillo-Velarde Map (Figure 1), the galleons usually anchored on the Port of Ticao (present-day San Fernando). It was approximately 10 kilometres south of the Port of San Jacinto. Another anchorage lies on the northernmost tip of the island, known as the Port of San Miguel. It was probably a port of call during the galleon trade since the galleons were ‘turning ENE around the Punta de San Miguel and the Punta del Diablo [both in San Miguel]; [before] coasting around the east side of Ticao to the anchorage at San Jacinto’ (Schurz 1939, 222). 7 �The Impact of the Galleon Trade on Ticao Island and San Jacinto When the Spanish arrived, Ticao Island had sporadic communities with trading and burial traditions (See Evangelista and Paniza 1962). Its centre was also named Ticao (present-day San Fernando). According to local history, Ticao became a pueblo in 1701 CE (Merillo 1980). However, unlike the galleon port of San Jacinto, protected by a fortress and at least five watch posts, Ticao was virtually defenceless. As a result, that town was easily crushed by Iranun slave raiders in 1757 CE (Warren 2002). After the atrocities, ‘All the inhabitants of Ticao Island were re-concentrated in the port of San Jacinto’ (Dery 1986, 160). By 1804 CE, San Jacinto was established as the new and only town on Ticao Island (De la Cavada 1876, 262). More than two centuries later, San Jacinto remains a quaint town with a seaport and various fish ports. Its past as a galleon port is immortalised in its church. Now called the Church of the Santo Cristo de Burgos, this parish used to house the relic of Jesus Christ that was saved from the burning galleon Santo Cristo (Gerona 2012, 78). Moreover, the galleon Santo Cristo's tragedy has been integrated into the oral tradition of San Jacinto, which has been passed down in the community for almost three centuries. In terms of resources, the southwest tip of Estero de Sta. Rosa (now the Tutuban River) in the Bertodano 1792 CE map (Figure 3c) is still the source of freshwater in the village of Tutuban. Its tributary pointing to the south is now a fishpond in Pararatngan, leading to Cueva in Burgos's village, ‘the source of the water system in San Jacinto’ (Espares 1953, 6). Lastly, the galleon trade and the Dutch and British intrusions made the port (and later the port town) of San Jacinto cosmopolitan. Hence, it has been passed down through oral tradition and local history that some Dutch, English, Portuguese, and Spanish crewmembers of the frigates and other vessels, such as the galleons, intermarried with the town’s inhabitants (Magdaraog 1968.; Merillo 1981). In particular, the ‘original families’ in the village of Tutuban, where the freshwater for the galleon was acquired, ‘were of mixed breed—Spanish, Dutch, and English’ (Villamor c. 1953, 1). BIBLIOGRAPHY Alba, Larry. Santo Cristo Underwater Archaeological Exploration Project. Unpublished Manuscript, Manila: National Museum of the Philippines, 2004. Almodal, Angeles V. “History and Cultural Life of San Jacinto,” Historical Data Papers (San Jacinto, Masbate). Manila: National Library of the Philippines, c. 1953. Barrun, Hermogenes E. History and Cultural Life of the Barrio [Mabini],’ Historical Data Papers (San Jacinto, Masbate). Manila: National Library of the Philippines, c. 1953. Beyer, H. Otley. “Outline Review of Philippine Archaeology by Islands and Provinces.” The Philippine Journal of Science 77, nos. 3-4 (1947): 205-390. Bolunia, Mary Jane Louise A. “Astilleros: the Spanish shipyards of Sorsogon.” In Proceedings of the 2nd Asia-Pacific Regional Conference on Underwater Cultural Heritage, edited by Hans Van Tilburg, Sila Tripati, Veronica Walker, Brian Fahy, and Jun Kimura. Honolulu, APCONF Committee, 2014. Bureau of Fisheries and Aquatic Resources. Philippine Fisheries Profile 2020. Quezon City: BFAR, 2021. Careri, Giovanni Franceso Gemelli. A Voyage to the Philippines. Translated from Giro del Mondo del dottor D. Gio Francesco Gemelli Careri. Parte Quinta Contenente le Cose più ragguardevoli vedute nell´isole Filippine, published 1700. Translated by Filipiniana Book Guild. Manila: Filipiniana Book Guild, 1983. Conese, Eduardo E. Underwater Archaeology in the Philippines. Unpublished Manuscript, Manila: National Museum of the Philippines, 1989. 8 �Cuevas, Maharlika. Ticao Pass (Bulan) Underwater Archaeological Project: A Field Report. Unpublished Manuscript, Manila: National Museum of the Philippines, 1985b. De la Cavada y Méndez de Vigo, Agustin. Historia geográfica: geológica y estadiśtica de Filipinas. Con datos geográficos, geológicos y estadiśticos de las islas de Luzon, Visayas, Mindanao y Joló; y los que corresponden a las islas Batanes, Calamianes, Balabac, Mindoro, Masbate, Ticao y Burias, situadas al n. so. y s. de Luzon, tompo 1-2. Manila: Imp. de Ramirez y Giraudier, 1876. Dery, Luis C. ‘The Era of the Kris: The Moro Raids in Sorsogon and Kabikolan and their impact on Philippine history, 15711896.’ National Academy of Science & Technology, 11 (1989): 145-166. Evangelista, Alfredo E., and Inocentes P. Paniza. A Preliminary Report on the Archaeological Survey of Burias, Ticao and Masbate Islands (April 1 to May 31, 1962). Unpublished Manuscript, Manila: National Museum of the Philippines, 1962. Espares, Bienvenido A. “History of the Barrio of Burgos,” Historical Data Papers (San Jacinto, Masbate). Manila: National Library of the Philippines, c. 1953. Fish, Shirley. The Manila-Acapulco Galleons: The Treasure Ships of the Pacific: With an Annotated List of the Transpacific Galleons 1565-1815. Milton Keynes: Authorhouse, 2011. Gerona, Danilo M. Las Islas de Masbate: A Beacon of Faith, A Fortress of Resistance. Masbate: Diocese of Masbate, 2012. Gerona, Danilo M. El Puerto Y Astillero Real de Pasacao. Pasacao: Office of the Mayor, 2018. Jago-on, S.C.B., Orillaneda, B.C. “Archaeological Researches on the Manila Galleon Wrecks in the Philippines.” In Archaeology of Manila Galleon Seaports and Early Maritime Globalization, The Archaeology of Asia-Pacific Navigation, vol. 2, edited by Chunming Wu, Roberto Junco Sanchez, and Miao Liu, 129-145. Springer, Singapore, 2019. La Follette, Cameron, and Douglas Deur. 2018. “Views Across the Pacific: The Galleon Trade and Its Traces in Oregon.” Oregon Historical Quarterly 119, no. 2 (2018): 160-191. Magdaraog, Victor. 1968. “San Jacinto, Ticao Island.” In The Historical and Cultural Heritage of the Bicol People, 2 nd Edition, edited by James J. O’Brien. Naga: Ateneo de Naga. Mallari, Francisco. “Camarines Towns: Defenses against Moro Pirates.” Philippine Quarterly of Culture and Society 17, no. 1 (1989): 41–66. Malones, Antonio Jr. The Encarnation. Unpublished Manuscript, Manila: National Museum of the Philippines, 1985 Merillo, Damaso. History of San Jacinto and Ticao Island Masbate. Unpublished Typescript, 1981. Montero y Vidal, Jose. El archipiélago Filipino y las islas Marianas, Carolinas y Palaos. Madrid: Imprenta y Fundación de M. Tello, 1886. Morado, Arturo B. c. 1953. “The Origin of the name “Bagahanglad” and its sitios,” Historical Data Papers (San Jacinto, Masbate). Manila: National Library of the Philippines, c. 1953. Non, Domingo M. “Moro Piracy during the Spanish Period and Its Impact.” Southeast Asian Studies 30, no. 4 (1993): 401419. Pelorina, Renato. “Plunder of Paradise: The History of Forest Denudation of Masbate Island, the Philippines, 1870-1946.” Researchers World: Journal of Arts, Science & Commerce 6, no. 2 (2015): 52-66. Philippine Commission of Independence. Beautiful Philippines: A Handbook of General Information. Manila: Bureau of Printing, 1923. Realubit, Maria Lilia F. Bikols of the Philippines. Naga: A.M.S. Press, 1983. Schurz, William Lytle. The Manila Galleon. New York: E. P. Dutton & Co., Inc., 1939. Villamor, Domingo S. “History and Common Life of the Barrio of Tutuban,” Historical Data Papers (San Jacinto, Masbate). Manila: National Library of the Philippines. c. 1953. 9 �Warren, James Francis. Iranun and Balangingi: globalization, maritime raiding and the birth of ethnicity. Singapore: NUS Press, 2002. Warren, James. ‘Weather, History and Empire: The Typhoon Factor and the Manila Galleon Trade, 1565-1815.’ In Anthony Reid and the Study of the Southeast Asian Past, edited by Geoff Wade, and Li Tana, 183-220. Singapore: ISEAS, 2012. Westerdahl, Christer. “The maritime cultural landscape.” The International Journal of Nautical Archaeology 21, no. 1 (1992): 5-14. Westerdahl, Christer. “The Maritime Cultural Landscape.” In The Oxford Handbook of Maritime Archaeology, edited by Alexis Catsambis, Ben Ford, and Donny L. Hamilton, 733-76. Oxford: Oxford University Press, 2011. 10 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource 2023 Session 12: The Archaeology of the Manila Galleon at the APCONF: past, present and new interpretations. Subject The topic of the resource Session 12 papers Description An account of the resource Papers presented at Session 12 of the 2023 Asia Pacific Regional Conference on Underwater Cultural Heritage Creator An entity primarily responsible for making the resource Asia Pacific Regional Conference on Underwater Cultural Heritage Publisher An entity responsible for making the resource available The Museum of Underwater Archaeology Date A point or period of time associated with an event in the lifecycle of the resource November 2023 Rights Information about rights held in and over the resource Asia Pacific Regional Conference on Underwater Cultural Heritage Language A language of the resource English Rights Holder A person or organization owning or managing rights over the resource. Asia Pacific Regional Conference on Underwater Cultural Heritage Document A resource containing textual data. Note that facsimiles or images of texts are still of the genre text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource The Maritime Cultural Landscape of the Port of San Jacinto and the galleon shipwrecks in Ticao Pass, Central Philippines Description An account of the resource During the Spanish colonial period, European explorers noted that Ticao Island in the Central Philippines was the source of water, wood, and other galleon provisions. Hence, the Port of San Jacinto in Ticao was one of the last ports the galleons touched before sailing into the Pacific, and vice versa. Ticao Pass is the graveyard of galleons such as Encarnación (1649) and Santo Cristo de Burgos (1726) to the east of the island. Through the years, local histories have been written about the island's glorious past as a galleon port. However, only a little archaeology has been done on this subject. Thus, this study aims to report the status of the archaeological research on Ticao’s role in the galleon trade. This paper charts relevant historical sites, i.e., potential archaeological sites, for future reconnaissance. The resources available to conduct the work include ethnohistorical data, archival maps, maritime charts, archaeological reports, site discovery forms, and artefacts. These resources are deemed ample to illustrate the maritime cultural landscape of the Port of San Jacinto, the underwater archaeology of the galleon shipwrecks in Ticao Pass, and the lasting impact of galleon trade in the island, especially in the town of San Jacinto. Creator An entity primarily responsible for making the resource Catherine E. Villamor Publisher An entity responsible for making the resource available The Museum of Underwater Archaeology Date A point or period of time associated with an event in the lifecycle of the resource 2023 Language A language of the resource English Bibliographic Citation A bibliographic reference for the resource. Recommended practice is to include sufficient bibliographic detail to identify the resource as unambiguously as possible. Villamor, Catherine E.. 2023. “The Maritime Cultural Landscape of the Port of San Jacinto and the galleon shipwrecks in Ticao Pass, Central Philippines.” Edited by Jennifer Craig, Jay Mok, T. Kurt Knoerl, and Jose L Casaban. In Proceedings of Fifth Asia Pacific Regional Conference on Underwater Cultural Heritage: Gwangju, The Republic of Korea, November 13-18 2023. The Museum of Underwater Archaeology. URL: https://apconf.omeka.net/exhibits/show/apconfproceedings/item/1959 Asia-Pac Session 12 2023 https://apconf-much.org/proceedings/files/original/86af14bc2aa55c27023df363881bcd22.pdf 3902bc40c22049db084f451751c1fff0 PDF Text Text The post-treatment deterioration of marine archaeological wood – where to now? Godfrey, I. M.1*, Richards, V. L.2 and Cha, M. Y.3 Abstract As waterlogged wood is ubiquitous in excavation sites, being used for structures (ships and buildings), tools, personal effects and for decorative artefacts, this material has been the subject of most conservation research and treatment over the past few decades. The development of disfiguring white deposits on treated timbers from the Skuldelev Viking ships from Roskilde Fjord in the late 1970s was initially treated as a minor cosmetic problem. The seriousness of the situation was soon realized when more timbers were affected and the destruction of timber tissue became evident. Similar problems have also been encountered with the Batavia timbers from Western Australia, the Shinan ship in Korea and artefacts from the Mary Rose in England. Problems associated with the presence of iron corrosion products in treated, formerly waterlogged timbers were further highlighted in 2000 with the development of highly acidic regions on some Vasa timbers and associated artefacts. These outbreaks on the Vasa were thought to be related to the inability of the climate control system to keep the relative humidity in the gallery below 60%. These post-treatment developments prompted a significant period of focused research and conservation activities, this time involving multi-faceted analyses and the development of strategies to address a problem that has the potential to affect all waterlogged timbers excavated from anaerobic sites. This paper reviews the current situation regarding the role that iron species play in promoting the formation of acidic species and in catalyzing the oxidation of reduced sulfur species, cellulose and polyethylene glycol and the steps being taken to reduce post-treatment deterioration of formerly waterlogged wood. The implications for future conservation treatments of waterlogged wood are discussed. Introduction Waterlogged wood is ubiquitous in wet terrestrial or underwater excavation sites, being used for structures (ships and buildings), tools, personal effects and for decorative artefacts. As a result waterlogged wood has been the subject of much conservation research and treatment over the past few decades. The work has been essential because waterlogged wood may be irreversibly damaged by shrinking, cracking, warping and possibly even crumbling into fragments should it be allowed to dry in an uncontrolled fashion (Figure 1). 1 Corresponding author, Dr Ian Godfrey, Department of Materials Conservation, Western Australian Museum, AUSTRALIA, ian.godfrey@museum.wa.gov.au 2 Department of Materials Conservation, Western Australian Museum, AUSTRALIA, vicki.richards@museum.wa.gov.au 3 Underwater Excavation and Conservation Division, National Research Institute of Maritime Culture Heritage , KOREA, cmy040301@nate.com �Figure 1: Cross-sectional view of conserved (top) and untreated wood (bottom) showing the extent of shrinkage if highly degraded wood dries without treatment (Copyright: Western Australian Museum). The aims of all conservation treatments should be to stabilize artefacts so that as much of the original material is preserved as possible, the dimensions of the object are retained and the causes of deterioration are ameliorated. Designated treatments should involve minimum intervention and if possible, applied treatments should be reversible or at least retreatable. Although reversibility is often quoted as an important principle for conservation treatments, it is often very difficult to achieve in practice. As long as dimensional change is avoided, the ability to retreat organic objects is enhanced if voids in structures are left unfilled, allowing future access to either solvents or alternative treatment chemicals. The importance of being able to retreat organic archaeological objects is clearly highlighted in the case of alumtreated waterlogged wood that has subsequently become highly acidic (Braovac and �Kutze in press). If it was not possible to retreat this wood, highly valuable archaeological objects would be lost forever. Many different conservation treatments have been applied to waterlogged wood. Most treatments focused on preserving the wood surfaces and dimensions upon drying. From the mid 19th century to the 1960s, heated, saturated alum solutions [KAl(SO4)2] were the most commonly used treatment for waterlogged wood (Herbst 1861:174-176). The aim was for the alum to displace the water and fill the pores with a material that would solidify when cooled and dried. Unfortunately alum was not able to fully penetrate the wood, was non-uniformly distributed throughout the wood and left it prone to collapse. In addition, over time, many alum-treated objects became highly acidic and deteriorated. In the early 1960s, the raising of the Vasa and excavation of the Skuldelev Viking ships from Roskilde Fjord stimulated further research into waterlogged wood treatment methods. As a result the alum treatment was abandoned and the use of polyethylene glycols (PEG) adopted as the preferred method for the conservation of waterlogged wood. For the past 45 years PEG, applied in different media and with various molecular weight and percentage compositions, has remained the most commonly used treatment for waterlogged wood. In addition to PEG however, many other techniques and chemicals have been used to impregnate and consolidate waterlogged wood. These include sugars and other polysaccharides (Franguelli 1971:339-346; Imazu and Morgós 1997:235-254; Imazu and Morgós 1999:210-214; Imazu and Morgós 2002:413-428; Zhang, et al. 2009:253-269), melamine/formaldehyde (Haas and Muller-Beck 1960:150-158; Wittköpper 1998:277-282), radiation-induced polymerization of vinyl monomers (Braeker and Bill 1979:97-145; Munnikendam 1967:70-75; Tran, et al. 1990:217234), silicone oils (Smith 2003) and acetone-rosin (McKerrell 1972:111-125). Despite the successful application of many of these techniques to waterlogged wood of varying degrees of degradation, none of these methods has overtaken PEG as the main treatment method for these archaeological materials. Post-treatment problems have surfaced however, in PEG-treated archaeological wood. The development of highly acidic regions in the Skuldelev Viking ships (Jespersen 1989:141-152), the Batavia (Ghisalberti, et al. 2002:281307), the Vasa (Sandström 2003), the Shinan ship (Kim and Yang 2004) and on artefacts from the Mary Rose (Wetherall, et al. 2008:1317-28) highlighted issues related to display environments and the complex chemical reactions that continue in waterlogged wood post-treatment. This paper examines the situation with regard to PEG-treated wood, presents the results of the latest research and discusses the implications with respect to the future conservation and research requirements of waterlogged wood. The nature of the problem The acid salts problem associated with PEG-treated wood was first highlighted in the late 1970s when disfiguring white deposits formed on treated timbers from the Skuldelev Viking ships recovered from Roskilde Fjord. The issue was initially treated as a minor cosmetic problem, with the powders simply brushed away and the spots camouflaged with tinted paint. The seriousness of the situation was soon realized when more timbers were affected and the destruction of timber tissue became evident (Jespersen 1989:141-152). Kirsten Jespersen’s analyses identified the white powder as hydrated iron sulfate, formed by oxidation of insoluble iron sulphides (FeS �and FeS2). Astutely, Jerspersen also recommended relative humidity control as being the key to protecting treated timbers from deterioration and encouraged cooperation with chemists to find methods by which iron salts could be removed prior to impregnation treatments. Similar problems had also been encountered with the Batavia timbers and as a result, subsequent research focused on further refining the problem, examining whether the problem was purely chemical in nature or if microbiological activity also played a role (MacLeod and Kenna 1991:133-142). Problems associated with the presence of iron corrosion products in PEGtreated wood were further highlighted in 2000 with the development of highly acidic regions on many Vasa timbers and associated artefacts. These outbreaks were thought to be related to the inability of the climate control system to keep the relative humidity in the display gallery below 60% (Sandström, et al. 2003). High relative humidity is also strongly linked to the development of acidity in the Batavia timbers when the climate control system breaks down and in the Shinan ship due to the naturally high summer humidity and temperatures in South Korea. The Skuldelev ships, the Batavia, the Shinan ship, the Vasa and wooden artefacts from the Mary Rose have common problems related to the complex interactions between the wood and the assorted chemicals incorporated into the wood structure during their immersion in the marine environment and as part of their conservation treatment. Corrosion products from corroding iron objects/fastenings and sulfur produced by sulphate reducing bacteria under anaerobic conditions in the marine environment permeated the timbers prior to excavation. Recovered timbers were then treated with PEG. Storage and/or display in high relative humidity environments encouraged chemical reactions between iron salts, reduced sulfur species, PEG and degraded cellulose that led to the development of highly acidic regions in and on timbers and other wooden artefacts from these iconic shipwrecks (Figure 2). This prompted extensive scientific investigations into the complex chemistry associated with these problems and suitable treatments to reduce acidity and ameliorate further deterioration. �Figure 2. Acid-affected region on a hull timber of the Shinan ship (Copyright: National Research Institute of Maritime Cultural Heritage, Korea). Iron compounds found on and inside acid-affected timbers include reduced and oxidized species, specifically pyrite, goethite, melanterite, rozenite, jarosite, natrojarosite, magnetite, siderotil and siderite (Cha in press; Ghisalberti, et al. 2002:281-307; Jespersen 1989:141-152; MacLeod and Kenna 1991:133-142; Sandström, et al. 2003). Acid levels in iron-rich areas range from pH4 0 to 3.5. Although only very low levels of pyrite were detected in Vasa timbers, relatively high levels of sulfur were found, predominantly in the form of elemental sulfur and thiols 5 of the cysteine6 type (Sandström, et al. 2003). In Batavia timbers however, higher levels of pyrite and only small quantities of elemental sulfur were found (MacLeod and Kenna 1991:133-142). The development of acid salt problems focused attention on the role that iron plays in promoting the formation of acidic species and in catalyzing the oxidation of reduced sulfur species, cellulose and PEG. Catalysed oxidation of reduced sulfur species, such as pyrite and elemental sulfur, leading to the production of sulfuric acid, was initially thought to be one of the main degradation mechanisms occurring in treated archaeological timbers (Ghisalberti, et al. 2002:281-307; Sandström, et al. 2003). While acidic hydrolysis of cellulose and hemicelluloses undoubtedly 4 pH – negative log10 of the hydrogen ion concentration. thiol - an organosulfur compound that contains a –C–SH or R–SH group where R represents an alkane, alkene, or other carbon-containing group of atoms. 6 Cysteine – a thiol-containing α-amino acid. 5 �contributes to deterioration of treated timber, subsequent studies demonstrated that there was less degradation in organically bound sulfur-rich areas of the Vasa and higher levels of degradation in low sulfur, high iron regions (Almkvist 2008). These findings indicated that organically bound sulfur was acting as an anti-oxidant and reducing the catalytic effects of iron compounds in these areas. In addition to the contribution to acid development by the oxidation and hydrolysis of iron salts and the production of sulfuric acid, iron species have also been implicated in free radical reactions, the acid hydrolysis of cellulose and other species, the oxidative depolymerisation7 of cellulose and PEG (Almkvist 2008; Elding in press; Godfrey, et al. in press; Lindfors, et al. 2007:57-63), the depolymerisation of hemicellulose and the formation of increased amounts of low molecular weight organic acids (formic, oxalic, acetic and glycolic acids) in sub-surface Vasa timber sections that have high iron to sulfur ratios (Almkvist 2008). While acetic acid generation can be directly linked to hemicellulose breakdown, the presence of greater amounts of formic acid in PEG-rich areas indicate that oxidative degradation of PEG is the major source of this acid (Almkvist 2008; Godfrey, et al. in press). It became clear that the situation in iron-impregnated, PEG treated wood is far more complex than originally thought, with more than just sulfuric acid contributing to the acidity of the timbers. Where to now? The increased knowledge regarding post-treatment deterioration of waterlogged wood necessarily imposes on cultural heritage professionals the need to carefully consider their actions with regard to the management of this valuable cultural resource. Some of the questions facing heritage management professionals include:  What can be done to minimise further deterioration in archaeological wood that is already in a treated, dry state?  If timbers are excavated with the intent of conservation, how should current treatment regimes be altered to minimise on-going post-treatment deterioration?  For already excavated timbers for which conservation treatments are not yet complete, can treatment regimes be modified to take into account recent research developments?  Should timbers continue to be excavated for study and conservation and if excavation is undertaken, is study, documentation and then re-burial an appropriate preservation management strategy? Conserved, dry wood It is clear that although waterlogged timbers initially appear to be stable after treatment with PEG, deterioration may continue long after the timbers have been dried. As low molecular weight PEGs are hygroscopic8 their presence in wood, combined with elevated relative humidity levels, enables sufficient moisture to be retained for chemical reactions to continue in the ‘dry’ archaeological wood. For already treated archaeological wood there are limited options to minimize further deterioration, all of which come at a significant cost. These options depend on the 7 8 Depolymerisation – a reaction which leads to the break up of polymer chains into smaller units. Hygroscopic – readily absorbs moisture from the air �condition, size and state of the wood - are they part of a hull structure for instance? In this latter case, as typified by timbers in the Vasa, post-PEG treatment options are extremely limited due to the restricted access to individual timbers in the multilayered hull structure. More options are available however for the timbers in the Batavia hull reconstruction as each timber can be individually removed and re-treated if necessary. As first muted by Jespersen (1989:141-152), environmental control of the storage/display environment, primarily by a reduction in the ambient relative humidity, is critical to the mitigation of deterioration mechanisms. While the capital cost for humidity control systems and the on-going running costs are very high, for large objects such as complete hull structures, this may be the only option available to minimise further degradation. The Vasa Museum installed a new air conditioning system in 2004, reducing the relative humidity in the display environment from upper levels of 65 – 70 % to a target range of 51 – 59 %. The effectiveness of this change has been reflected in a dramatic decrease in the number of acidic outbreaks that have occurred following this change in display conditions (Hocker, et al. 2009:469481). By comparison, the conditions in the Batavia display gallery are currently maintained at 47 – 57 %, reduced from 50 – 60 %, in an attempt to reduce the incidence of acidic outbreaks. Conservation professionals continue their efforts to determine the best treatment options for recovered waterlogged wood and to examine methods by which already treated wood can be better preserved. In order to minimise the post conservation problems associated with treated timbers, it is necessary to examine the kinetics of deterioration processes, the rate of oxygen consumption in treated timbers, and the environmental requirements that are needed in order to minimise deterioration processes. Research is continuing in all of these directions with recent research shedding further light on aspects of deterioration processes including PEG degradation (Almkvist and Persson 2005:269-278; Mortensen, et al. 2005:261-267; Mortensen et al. in press), oxygen consumption and measurement in conserved archaeological wood (Matthiesen and Nordvig in press) and the effects of consolidants on moisture absorption (and hence on the rates of chemical reactions) in conserved wood (Jensen, et al. in press). These and more studies are needed in order to fully understand the nature of the problem and the best way(s) to reduce degradation of treated archaeological wood. Treatment of excavated archaeological wood Despite research into alternative impregnation and consolidation regimes, PEG impregnation is still the most widely used treatment method for waterlogged wood. Disadvantages of its use however, include its cost, surface finish (dark, waxy and unnatural colour unless carefully cleaned) and its hygroscopicity that necessitates careful control of the relative humidity of storage and display environments for PEG treated wood. PEG is viewed by some as being only suitable for short-term stabilization because of its degradation over time (Christensen, et al. 2010:1-7). Mikkel Christensen also considers that research is needed in order to develop a more appropriate consolidant that leaves ‘an airy structure in order to allow re-treatment in the future’ and that modern materials science should be applied to develop more durable impregnation regimes, possibly involving ‘foaming a polymer’, a combination of nanoparticles with a polymeric ‘spider web’, a framework using biomimetic �materials such as an artificial lignin or via biomineralisation with an inorganic skeleton (Christensen 2010:1-7). Until such time as a more appropriate consolidant is developed however, PEG use is likely to continue. If this is the case then it is critical that any treatment regime include steps to remove iron compounds from waterlogged wood. The extent of iron removal needed to minimise continuing degradation of polysaccharides and PEG is still to be determined. Research efforts should therefore be made to determine if there is a threshold concentration of iron at which these degradation mechanisms are of minimal impact. Unfortunately the complex nature of deteriorated wood components, incorporated chemicals from the burial environment and the differing grades, concentrations and purities of PEG used to treat archaeological wood, complicate research efforts in this area. In the early 1990s preliminary experiments on the extraction of iron corrosion products from degraded, iron impregnated waterlogged wood found that the use of sodium dithionite in conjunction with diammonium citrate and PEG solutions, at neutral pH, was very effective in removing iron minerals from iron impregnated timber whilst successfully stabilising the wood structure (MacLeod, et al. 1991:119-132; MacLeod, et al. 1994:199-211). More recently, high performance iron chelators, diethylenetriamine pentaacetic acid (DTPA) and ethylenediimino-bis (2-hydroxy-4methylphenyl) acetic acid (EDDHMA), have been successful in removing iron corrosion products from acid-affected, PEG treated waterlogged wood (Almkvist and Persson 2006:678-684). Potential problems with the latter treatment however, include degradation of hemicelluloses due to the alkaline nature of the chelating solution9 and post-treatment removal of the rich red colour that the iron-EDDHMA complex imparts to the wood. While research continues in this area, a comparison of the sodium dithionite/ammonium citrate/PEG treatment with both the DTPA and EDDHMA treatments, found that the former solution was significantly more effective in removing iron from waterlogged wood (Richards et al. in press). Reburial of waterlogged wood Excavation, study, documentation and reburial of waterlogged, archaeological wood may be a valid conservation management option for some, though not all, of these problematic materials. Reburial of excavated archaeological materials has long been used as a management tool, particularly in cases where large numbers of similar artefacts have been recovered, where the conservation budget is insufficient to allow the treatment of all objects, where the display or further research value of objects is limited or when sufficient archaeological information can be obtained from the objects without the necessity of a full conservation treatment (Bergstrand, et al. 2005:9-39; Godfrey, et al. 2004:343-351; Manders, et al. 2008:179-203). Depth of burial has been found to be a very important parameter when relating the degree of wood decay to the local environment. Many authors have shown that the extent of biological degradation of wood decreases considerably with burial depths greater than 50cm (Björdal and Nilsson 2002:235-244; Gregory 1999:78-83). However, recent studies have indicated that to decrease degradation of wood to almost negligible levels the depth of burial may need to be significantly greater than 9 Chelating solution – a solution containing a chemical that binds strongly to a metal, forming a soluble, complex molecule. �50cm (Bergstrand and Nyström Godfrey 2007:207-224; Nyström Godfrey, et al. 2011; Richards, et al. 2009:113-160). So based on past and current research, long-term preservation of reburied wood requires burial depths of over 50cm, in an environment which is sub-oxic to anoxic, is strongly reducing in nature with near neutral pH and dominated by anaerobic chemical and microbiological processes (sulphate reduction and methane production). In addition, the porosity of the reburial sediment should be low and possess almost negligible levels of interstitial organic materials such as dead seagrass, other dead/decaying organic matter or organic pollutants. More importantly, the area in which the material is reburied needs to be stable and not subjected to significant sediment movement through excessive water movement, such as strong current flow, large tidal ranges and frequent storm events (Nyström Godfrey, et al. 2011). Conclusions Although the guidelines for the conservation and preservation of underwater cultural heritage, developed by UNESCO in 2001, strongly endorse the in situ preservation of underwater cultural heritage sites and artefacts (UNESCO 2001), wood will continue to be excavated from at least some underwater sites. Port developments, underwater pipeline construction and dredging operations for example, often interact with shipwreck or other submerged archaeological sites. In these instances, excavation and either documentation, conservation or reburial, even at an alternative site may need to be considered. More research is needed with regard to the development of durable conservation treatments, for the amelioration of deterioration processes in already treated wood and in the development of protocols and guidelines for the effective preservation of waterlogged wood by reburial. Bibliography The chemistry of the Vasa – Iron, acids and degradation, Doctoral Thesis No 2008:57, Swedish University of Agricultural Sciences, Uppsala. Almkvist G. and The movement and stability of PEG in the Vasa wood. In P. Persson I., Hoffmann, K. Straetkvern, J. A. Spriggs and D. A. Gregory (Eds), Proceedings of the 9th ICOM Group on Wet Organic 2005 Archaeological Materials Conference, Copenhagen, 2004, ICOM-CC, Bremerhaven, pp 269-278. Almkvist, G. and Extraction of iron compounds from wood from the Vasa. Holzforschung, Vol. 60, pp 678-684. Persson, I., 2006 Braeker, O. U. and Zum derzeitigen stand der nassholzkonservierung. Zournal fur Schweizerische Archaologie and Kunstgeschichte, Vol. 36, pp Bill, J., 1979 97-145. Bergstrand, T., Reburial as a method of preserving archaeological remains. A Björdal, C.G., presentation of the Marstrand project. In P. Hoffmann, K. Strætkvern, J.A. Spriggs and D. Gregory (Eds), Proceedings of Bohm, C., the 9th ICOM Group on Wet Organic Archaeological Materials Christenssen, E., Conference, Copenhagen, 2004, ICOM-CC, Bremerhaven, pp Gregory, D., MacLeod, I.D., 9-39. Almkvist, G., 2008 �Nilsson, T., Nyström, I., Peacock, E. Richards, V.L. and Turner, G., 2005 Berstrand, T. and Nyström Godfrey, I. (eds), 2007 Björdal C. Nilsson T., 2002 and Cha, M. Y., in press. Christensen, M., Hansen, F. K. and Kutzke, H., 2010 Elding, L. I., in press. Franguelli, R., 1971-1972. Ghisalberti, E. L., Godfrey, I. M., Kilminster, K., Richards, V. L. and Williams, E., 2002 Godfrey I.M., Gregory D., Nyström I. and Richards V., 2004 Godfrey, I., Richards, V., Ghisalberti, E. and Byrne, L., in press. Gregory D., 1999 Reburial and Analyses of Archaeological Remains – Studies on the effect of reburial on archaeological materials performed in Marstrand, Sweden 2003-2005. The RAAR project. Udevalla, Sweden: Bohusläns Museum and Studio VästSvensk Konservering. Available at: <http://www9.vgregion.se/vastarvet/svk/reburial/index.htm> Decomposition of Waterlogged Archaeological Wood, in P. Hoffmann, J.A. Spriggs, T. Grant, C. Cook & A. Recht (Eds), Proceedings of the 8th ICOM Group on Wet Organic Archaeological Materials Conference, Stockholm 2001, ICOMCC, Bremerhaven, pp 235-244. Conservation of shipwrecks in Korea, International Meeting on Protection Presentation and Valorisation of Underwater Cultural Heritage, UNESCO and Chinese Academy of Cultural heritage, Chongqing, November 2010. New materials used for the consolidation of archaeological wood – past attempts, present struggles and future requirements. In Proceedings: Wood Science for Conservation of Cultural Heritage, International Conference on Wooden Cultural Heritage: Evaluation of Deterioration and Management of Change, Hamburg, 2009, pp 1-7. Vasa – Recent preservation research. In Proceedings of the 11th ICOM Group on Wet Organic Archaeological Materials Conference, Greenville, North Carolina, May 2010. Legni preistorici palustri e loro trattamento conservative. Sibrium XI, pp 339-346. The analysis of acid-affected Batavia timbers. In P. Hoffmann, J. A. Spriggs, T. Grant , C. Cook and A. Recht (Eds), Proceedings of the 8th ICOM Group on Wet Organic Archaeological Materials Conference, Stockholm, 2001, ICOMCC, Bremerhaven, pp 281-307. In-situ preservation of archaeological materials and sites underwater. In F. Maniscalco (ed.), Mediterraneum, Massa Editore, Italy, pp. 343-351. Nuclear magnetic resonance spectroscopic analyses of acidaffected waterlogged archaeological wood. In Proceedings of the 11th ICOM Group on Wet Organic Archaeological Materials Conference, Greenville, North Carolina, May 2010. Re-burial of ship timbers in the marine environment as a method of in-situ preservation. In C. Bonnet-Diconne, X. Hiron, �Q. K. Tran & P. Hoffmann (Eds), Proceedings of the 7th ICOM-CC Working Group on Wet Organic Archaeological Materials Conference, Grenoble, France 1998, ARC-Nucléart, Grenoble, pp 78-83. and A method for wood preservation using Arigal C. Studies in H., Conservation, Vol. 5, pp 150-158. Haas, A. Muller-Beck, 1960 Herbst, C. F., 1861 Hocker, E., Dal, L. and Hocker, F., 2009 Imazu, S. Morgós, A., 1997 and Imazu, S. Morgós, A., 1999 and Imazu, S. Morgós, A., 2002 and Jensen, P., Helms, A. C. and Christensen, M., in press Jespersen, 1989 K., Kim, I. J. and Yang S. S., 2004 Lindfors, E.-L, Lindström, M. and Om Bevaring af Oldsager af Træ fundet i Tørvemoser. Antiquarisk Tidsskrift 1858-60, København, pp 174-176. Understanding Vasa’s salt problem: Documenting the distribution of salt precipitations on the Swedish warship Vasa. In K. Straetkvern and D.J. Huisman (Eds), Proceedings of the 10th ICOM Group on Wet Organic Archaeological Materials Conference, Amsterdam, 2007, Rijksdienst voor Archeologie, Cultuurlandschap en Monumenten (RACM), Amersfoort, pp 469-481. Conservation of waterlogged wood using sugar alcohol and comparison of the effectiveness of lactitol, sucrose and PEG 4000 treatment. In P. Hoffmann, T. Daley, T. Grant and J. Spriggs (Eds), Proceedings of the 6th ICOM Group on Wet Organic Archaeological Materials Conference, York, 1996, ICOM-CC, Bremerhaven, pp 235-254. The lactitol conservation of a 6m long timber coffin. In C. Bonnot-Diconne, X. Hiron, Q. K Tran and P. Hoffmann (Eds), Proceedings of the 7th ICOM Group on Wet Organic Archaeological Materials Conference, Grenoble, 1998, ARCNucléart, Grenoble, pp 210-214. An improvement on the lactitol conservation method used for the conservation of archaeological waterlogged wood (The conservation method using a lactitol and trehalose mixture). In P. Hoffmann, J. A. Spriggs, T. Grant , C. Cook and A. Recht (Eds), Proceedings of the 8th ICOM Group on Wet Organic Archaeological Materials Conference, Stockholm, 2001, ICOMCC, Bremerhaven, pp 413-428. Evaluating long-term stability of waterlogged archaeological wooden objects through determination of moisture sorption isotherms and conductivity in conserved objects and impregnation agents. In Proceedings of the 11th ICOM Group on Wet Organic Archaeological Materials Conference, Greenville, North Carolina, May 2010. Precipitation of iron-corrosion products on PEG-treated wood. In I.D. MacLeod (Ed.), Conservation of Wet Wood and Metal: Proceedings of the ICOM Conservation Working Groups on Wet Organic Archaeological Materials and Metals, Fremantle, 1987, Western Australian Museum, Perth, pp 141-152. Conservation of Shinan Ship. The Conservation and Restoration Report of Shinan Ship. National Maritime Museum, Korea, pp 16-37. Polysaccharide degradation in waterlogged oak wood from the ancient warship Vasa. Holzforschung, Vol. 62, pp 57-63. �Iversen, T., 2007 MacLeod, I. D. and Degradation of archaeological timbers by pyrite: Oxidation of iron and sulphur species. In P. Hoffmann (Ed.), Proceedings of Kenna, C., the 4th ICOM Group on Wet Organic Archaeological Materials 1991 Conference, Bremerhaven 1990, ICOM-CC, Bremerhaven, pp 133-142. MacLeod, I. D. and Degradation of archaeological timbers by pyrite: Oxidation of iron and sulphur species. In P. Hoffmann (Ed.), Proceedings of Kenna, C., the 4th ICOM Working Group on Wet Organic Archaeological 1991 Materials Conference, Bremerhaven, 1990, ICOM-CC, Bremerhaven, pp 133-142. MacLeod, I. D., Iron corrosion products and their interactions with waterlogged Brooke, P. and wood and PEG. In P. Hoffmann (Ed.), Proceedings of the 4th ICOM Working Group on Wet Organic Archaeological Materials Richards, V., Conference, Bremerhaven, 1990, ICOM-CC, Bremerhaven, pp 1991 119-132. MacLeod, I. D., Observations on the extraction of iron and chloride from Mardikian, P. and composite materials. In P. Hoffmann, T. Daley and T. Grant Richards, V. L., (Eds), Proceedings of the 5th ICOM Group on Wet Organic Archaeological Materials Conference, Portland/Maine, 1993, 1994 ICOM-CC, Bremerhaven, pp 199-211. Manders, M., The in-situ preservation of archaeological sites underwater. An Gregory, D., evaluation of some techniques. In E. May, M. Jones and J. Mitchell (Eds), Proceedings of the 2nd Heritage, Microbiology Richards, V., and Science, Microbes, Monuments and Maritime Materials 2008 Conference, 28 June – 1 July 2005, Portsmouth, UK, ,RSC Publishing, pp 179-203. Matthiesen, H. and Oxygen measurements in conserved archaeological wood. In Proceedings of the 11th ICOM Group on Wet Organic Nordvig, M., Archaeological Materials Conference, Greenville, North in press. Carolina, May 2010. McKerrell, H., The acetone/rosin method for conservation of waterlogged Roger, E. and wood. Studies in Conservation, Vol. 17, pp 111-125. Varsanyi, A., 1972. Mortensen, M. N., PEG in the warship Vasa and the Viking ship Skuldelev 2. In P. Egsgaard, H., Hoffmann, K. Straetkvern, J. A. Spriggs and D. A. Gregory Shashoua, Y. and (Eds), Proceedings of the 9th ICOM Group on Wet Organic Archaeological Materials Conference, Copenhagen, 2004, Glastrup, J., 2005 ICOM-CC, Bremerhaven, pp 261-267. Mortensen, M. N., Formic acid as a marker molecule for polyethylene glycol Egsgaard, H., degradation in conserved archaeological wood – a radiocarbon Hvilsted, S., and study. In Proceedings of the 11th ICOM Group on Wet Organic Archaeological Materials Conference, Greenville, North Glastrup, J., in press. Carolina, May 2010. Munnikendam, R. Conservation of waterlogged wood using radiation polymerization. Studies in Conservation, Vol. 12, pp 70-75. A., 1967 Nyström Godfrey, Reburial and Analyses of Archaeological Remains – Phase II I., Bergstrand, T results from the 4th retrieval in 2009 from Marstrand, Sweden. �The RAAR project. Udevalla, Sweden: Bohusläns Museum and Studio VästSvensk Konservering. Available at: <http://www9.vgregion.se/vastarvet/svk/reburial/index.htm> In-Situ monitoring and stabilisation of the James Matthews site. In K. Straetkvern & D.J. Huisman (Eds), Proceedings of the 10th ICOM Group on Wet Organic Archaeological Materials Conference, Amsterdam, September 2007, Rijksdienst voor Archeologie, Cultuurlandschap en Monumenten (RACM), Amersfoort, pp 113-160. Iron removal from waterlogged wood and the effects on wood chemistry, in Proceedings of the 11th ICOM Group on Wet Organic Archaeological Materials Conference, Greenville, North Carolina, May 2010. M., The Vasa’s new battle: Sulphur, acid and iron, Vasa Studies 19, and The Swedish National Maritime Museums, Stockholm. and Petersson, H. (eds.), 2011 Richards, V., Godfrey, I., Blanchette, R., Held, B., Gregory, D., and Reed, E., 2009 Richards, V., Kasi, K. and Godfrey, I., in press Sandström, Fors, Y. Persson, I., 2003 Smith, W., 2003 Archaeological Conservation Using Polymers: Practical Applications for Organic Artifact Stabilisation, College Station, Texas A&M University Press. Tran, K., Ramière, Preservation of waterlogged wood, Impregnation with radiationR., and Ginier- curing monomers and resins. In R. M. Rowell and R. J. Barbour (Eds), Archaeological Wood, Properties, Chemistry and Gillet, A., Preservation, Advances in Chemistry Series 225, American 1990 Chemical Society, Washington DC, pp 217-234. Wetherall, K. M., Sulfur and iron speciation in recently recovered timbers of the Mary Rose revealed via X-ray absorption spectroscopy, in Moss, R. M., Journal of Archaeological Science, Vol. 35, pp 1317-1328. Jones, A. M., Smith, A. D., Skinner, T., Pickup, D. M., Goatham, S. W., Chadwick, A. V., Newport, R. J., 2008 Wittköpper, M., Der aktuelle stand der konservierung archäologischer 1998 naßhölzer mit melamin/aminoharzen am RömischGermanischen Zentralmuseum. Arbeitsblätter für Restauratoren Gruppe 8: Holz Heft 2, pp 277-282. Zhang, J. P., Lactitol conservation of the 1st century BC extremely degraded Imazu, S., and waterlogged archaeological wooden figures and objects Morgós, A., excavated at the tomb of one of the kings of the ancient Sishui 2009 Kingdom in China. In K. Straetkvern and D.J. Huisman (Eds), Proceedings of the 10th ICOM Group on Wet Organic Archaeological Materials Conference, Amsterdam, 2007, Rijksdienst voor Archeologie, Cultuurlandschap en Monumenten (RACM), Amersfoort, pp 253-269. Convention on the Protection of the Underwater Cultural UNESCO, Heritage, UNESCO, Paris. 2001 � Document A resource containing textual data. Note that facsimiles or images of texts are still of the genre text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource The post-treatment deterioration of marine archaeological wood - where to now? Subject The topic of the resource Session 7 Preservation and conservation of wet archaeological materials and site management Description An account of the resource As waterlogged wood is ubiquitous in excavation sites, being used for structures (ships and buildings), tools, personal effects and for decorative artefacts, this material has been the subject of most conservation research and treatment over the past few decades. The development of disfiguring white deposits on treated timbers from the Skuldelev Viking ships from Roskilde Fjord in the late 1970s was initially treated as a minor cosmetic problem. The seriousness of the situation was soon realized when more timbers were affected and the destruction of timber tissue became evident. Similar problems have also been encountered with the Batavia timbers from Western Australia, the Shinan ship in Korea and artefacts from the Mary Rose in England. Problems associated with the presence of iron corrosion products in treated, formerly waterlogged timbers were further highlighted in 2000 with the development of highly acidic regions on some Vasa timbers and associated artefacts. These outbreaks on the Vasa were thought to be related to the inability of the climate control system to keep the relative humidity in the gallery below 60%. These post-treatment developments prompted a significant period of focused research and conservation activities, this time involving multi-faceted analyses and the development of strategies to address a problem that has the potential to affect all waterlogged timbers excavated from anaerobic sites. This paper reviews the current situation regarding the role that iron species play in promoting the formation of acidic species and in catalyzing the oxidation of reduced sulfur species, cellulose and polyethylene glycol and the steps being taken to reduce post-treatment deterioration of formerly waterlogged wood. The implications for future conservation treatments of waterlogged wood are discussed. Creator An entity primarily responsible for making the resource Godfrey, I. M. Richards, V. L. Cha, M. Y. Date A point or period of time associated with an event in the lifecycle of the resource November 2011 Asia-Pac Session 7 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Naval Warfare in Ancient India Creator An entity primarily responsible for making the resource Chakravarti, Prithwis Chandra Date A point or period of time associated with an event in the lifecycle of the resource 1930 Type The nature or genre of the resource Journal Article Zotero Author Chakravarti, Prithwis Chandra Item Type Journal Article Date A point or period of time associated with an event in the lifecycle of the resource 1930 Issue 4 Pages 645-64 Publication Title Indian Historical Quarterly Title A name given to the resource Naval Warfare in Ancient India URL http://ccbs.ntu.edu.tw/FULLTEXT/JR-ENG/cha.htm Volume 4 India Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource India’s Contribution to World Thought and Culture Creator An entity primarily responsible for making the resource Chandra, Lokesh Publisher An entity responsible for making the resource available Vivekananda Rock Memorial Committee Date A point or period of time associated with an event in the lifecycle of the resource 1970 Type The nature or genre of the resource Book Zotero Author Chandra, Lokesh Item Type Book Date A point or period of time associated with an event in the lifecycle of the resource 1970 Place Madras Publisher An entity responsible for making the resource available Vivekananda Rock Memorial Committee Title A name given to the resource India’s Contribution to World Thought and Culture India Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Trade and Trade Routes in Ancient India Creator An entity primarily responsible for making the resource Chandra, Moti Publisher An entity responsible for making the resource available Abhinav Publications Date A point or period of time associated with an event in the lifecycle of the resource 1977 Type The nature or genre of the resource Book Zotero Author Chandra, Moti Item Type Book Date A point or period of time associated with an event in the lifecycle of the resource 1977 Place New Delhi Publisher An entity responsible for making the resource available Abhinav Publications Title A name given to the resource Trade and Trade Routes in Ancient India India https://apconf-much.org/proceedings/files/original/77710d6077603fe8957d2fc6dab9a195.pdf 5c710db27a5bc588c9f61d14659dc159 PDF Text Text In-situ preservation In Tropical Seas: Case Study on the Avondster Shipwreck Chandraratne Wijamunige Abstract The VOC ship Avondster sunk on 2nd July 1659 when anchoring near the beach in Galle Bay, geographically located in the southern part of Sri Lanka. She was re-discovered in 1993 and subjected to a series of research projects including excavation in the bow, stern and mid-ship areas. Due to construction work in Galle Harbour it was important to protect the shipwreck in situ. The environment in the Galle Bay badly affected the wreck site and it was a big challenge to overcome all the harmful factors that were likely to damage the remains of Avondster. In order to preserve Avondster a plastic net was introduced as a protective layer over the wreck site. This was monitored constantly throughout and after the research period. The protective layer was used over the fragile timbers for nearly 8 years before a violent tsunami hit Galle Bay in December 2004. Despite the serious damage caused on the land by the tsunami, it had less effect on the site and the covering-plastic net was still intact. From that time on monitoring has continued every two months. This paper discusses in detail the present condition of the in situ protection and its validity as a preservation technique in the conditions found in tropical seas. Introduction The requirements to preserve the underwater cultural heritage (UCH) are now emphasized in the maritime archaeological field more now than previously. Due to new technology and well developed equipment diver numbers have increased. Some divers are engaged in various tasks and functions that can be harmful to the UCH in many ways. Submerged archaeological remains are regularly found all over the world day-by-day due to increased diving activities. The idea of preserving in-situ as seen in parts of the European continent and other economically developed countries prior to the year 2000. This trend is seen in the Asian region after the year 2000. For example, in Sri Lanka there were more than 30 maritime archaeological sites reported in the Southern coastal belt, of which 26 are in Galle Bay harbour. Despite the scarcity in human and technological resources, funds and minimal political involvement; the Maritime Archaeology Unit (MAU) team was able to record and do research on most of these sites during the last decade. In a developing country, such as Sri Lanka, the new trend to conduct insitu preservation and analysis is a better option than to excavate. It is an efficient way to scientifically identify the deterioration threats on recorded UCH sites which are being continuously discovered, and to rebury them and/or utilize other protection methods. Excavation costs huge amounts of money. In both the International Council on Monuments and Sites (ICOMOS) 1996 Charter and Article 01 of the United Nations Educational, Scientific and Cultural Organization (UNESCO) 2001 Convention on the Protection of Underwater Cultural Heritage (2001 Convention) emphasis is placed on, “in-situ protection should be the first option” (Prott 2003:xxiii). �One of the pioneer countries to have undertaken in-situ conservation methods on UCH is the Netherlands. Since the early 1980s they have identified the needs of in-situ preservation and practiced it with their projects. One of these was a project to conserve more than 30 sites in-situ in Zuiderzee - bed in the flevopolders area. Further in 1988 the BZN3 shipwreck site, which was owned by Dutch East India company (VOC), was protected physically and by the law (Manders, et al. 2004:1251-1252). In the same manner several shipwrecks were preserved in-situ in Europe, Australia and Canada: the wooden shipwreck in Red Bay, Canada (Manders, et al. 2008:179-194); the German 14th century merchant vessel Darssar Cog (Manders, et al. 2008:189); the 4th century Roman quay in the Netherlands (Manders, et al. 2008:190); and in Australia, the William Salthouse (1841) in Victoria and the James Matthews wreck (1841) in Fremantle (Manders, et al. 2008:192). Different methods were followed to preserve these sites considering the following facts: location, deterioration threats, environment, utility to the public and the technological improvements during that period. For example, sacrificial anode (see Godfrey, Richards and Cha this volume) treatment was used to preserve the metal parts of the James Matthews wreck in Fremantle, Western Australia (see Carpenter and Richards this volume). Thus far, Sri Lanka has only one example regarding in-situ conservation, the Avondster shipwreck situated in Galle Bay harbour. The purpose of this paper is to discuss the process of in-situ protection implemented on the Avondster shipwreck and its necessity, success or failure. History of Avondster Shipwreck The Avondster was originally a British ship (30-40 meters in length), captured and modified by the Dutch (http:cf.hum.uva.nl/galle/). The vessel was constructed with two decks and the capacity was 250-260 tonnage. After a long life span of long distance trans-oceanic voyages it was assigned to short-haul coastal runs. It was wrecked on July 2nd 1659 while anchored in the Galle Bay harbour (Parthesius, et al. 2005:220). After the ship was discovered in 1993 the site was monitored; it became clear that the wreck was increasingly exposed through changes in the dynamics of the seabed, and it was considered important to implement a rescue archaeology project on the site to safeguard this important collection (Manders, et al. 2004:1253). The wreck lies close to the shore, in 6 metres of murky waters (Figure 1). From the year 2001 until the end of 2004 important sections of the ship have been excavated and conserved in-situ. Explorations revealed in-situ wooden parts of the hull, brick construction of the galley, six iron cannons and one of the ship’s anchor. At the time when the yacht sunk the rudder was separated from the stern section because it struck the sandy sea bed (http:cf.hum.uva.nl/galle/). The rudder now lies 18 meters away from the main shipwreck. �Figure 1. Location of the Avondster/Site L. (Photo – WA museum) Reasons for Preservation in situ Even before the official discovery of the Avondster shipwreck, looters collected artefacts from the surrounding zone. With the monsoon activities every year the sea bed become rough with high waves and exposed to erosion. It had become a common practice of the local divers to collect exposed artefacts and things moving on the sea bed after the monsoon season (Carpenter 1996:44-50) The marine drive, built by the Road Development Authority of Sri Lanka in the late 1960’s, reduced the distance between the seashore and the wreck to 90 meters (previously it was about 150 meters); and in 2002, with the second stage of this development, reduced it to 70 meters. These developments and the construction of the stone barrier to stop sea erosion caused rapid changes to the coastal seabed. The natural sand and sediments which existed for hundreds of years shifted every year (Parthesius, et al. 2007:159). The high slope of the stone barrier directly impacted the seabed adjacent the beach, where the Avondster shipwreck lies. The waves from the open ocean struck the stone barrier with more force than the natural shore. This rolling wave pattern moved the sand from side by side causing erosion on the wooden wreck parts. The explorations made during the years 1997, 1998 and 1999 emphasized that the movable artefacts should be excavated and undergo sustainable conservation to prevent further erosion. This was included in the aims for the Avondster 2001 field season project (Parthesius, et al. 2005:221-222). In both theory and practice in-situ conservation is an acceptable method for Sri Lanka. I will explain why, first, through the legalities. This country’s legislature has the capacity to provide what is needed to protect the UCH. Under the Sri Lankan law conservation of both maritime heritage and UCH is included (Antiquity Ordinance No.19 of 1940 and it’s Amendment No.24 of 1998). �Avondster is one of the well preserved oldest wooden yachts found in Sri Lanka. As such there is a responsibility to keep it protected from damaging physical factors. At the time that three excavation trenches were initiated at the site there were neither maritime archaeologists armed with enough technological and scientific knowledge available in the country nor the infra-structural facilities needed with the MAU. The necessity of conserving this type of heritage for further scientific method study by future generations influenced the direction for its preservation. Though the legal protection bans treasure hunters, looters and fishermen, it isn’t enough to protect against the natural physical, chemical and biological processes. Avondster is situated in a place facing direct impact from tidal movement and/or changes in water circulation and sediment erosion (Manders, et al. 2004:1253), these actions cause an aerobic environment within which more oxygen enters the exposed wreckage creating good conditions for wood-borers and many bacteria (Bonke, et al. 2007:133). Also the fresh water flowing from two networks of gutters coming from the city increased this situation and brought more bacteria. It was a common scene to see the waste and garbage coming from the city floating in the water over the Avondster. During the first archaeological excavation on Avondster, on its front bow section, we were able to identify and observe the quick deterioration on the wooden parts after they were exposed. Due to above circumstances we had to cover the Avondster site. In February 2003 we decided to do a test project. A 4 x 4 meter area on the Avondster bow section was selected for the purpose. The highest parts of the hull's timber were coming out from the sea bed up to one and a half feet. A black plastic net (100% polypropylene and 60% density) was used for this purpose (Parthesius, et al. 2007:162). In order to prevent the net moving with the swell old iron chains were placed on it using plastic zip-ties/ty-raps (small plastic straps use to tie things). After covering it was monitored twice a week for one month. During the first month success was observed. At the end of the first month tears were seen in a number of points on the net. A sand deposit 10-15 cm thick was found under the net. As the marine growth has covered the small holes of the net any further deposit of sand could not be identified. The marine growth on the net helps to gather sand on the net and keep it stable (Weerasinghe and Manders 2003:10). Although it was believed for some period that the test programme would be a success and that we can use this system for the rest of the wreck, when we checked the situation a few month later (the diving was stopped for nearly four months due to the monsoon rain) the whole plastic covering was destroyed by the high waves. It was not strong enough to resist it. This helped us to understand the situation in this area and to select a more suitable net of greater strength and to better secure it. �Covering the shipwreck In implementing the main in-situ project after the failure of the first test our challenge was to select a more suitable and stronger net. We had to check many samples for the strength and for the density (strength by checking the material and try to tear it and density by checking the size of the holes of the net). Finally the 100% polypropylene and 40% - 50% density manufactured in Israel was selected as the most suitable net. The area needed for coverage on the Avondster shipwreck was estimated to 400 square meters. Fourteen pieces of 25 x 4 meter size nets were purchased. The specialty of this net was that it is stronger and wider than the previous one. With less density the holes in the net will help sand to permeate and deposit under it. The covering was placed in November 2003 from the bow section. Before taking the strip of net to the sea it was rolled from both sides to the middle. After placing it on the wreck the rolled strip was unrolled to the each side covering the wreck. In order to prevent the net from swinging some bags of sand were placed on both ends. The second net was placed overlapping the first one and the ends tied with plastic threads (zip-ties/ty-raps). In total four strips of net covered the ship from bow to mid-ship. Sand bags were put on some sharp wooden edges to prevent the damage caused to the net by swells (Weerasighe and Manders 2003:9). On some points we covered the wreck with some sand by using a water dredge in reverse, especially on the excavated areas. Monitoring and stabilization We placed sand bags on the net to prevent movement and damage but it did not stop it completely. The movement of the net helps sand and silt go though the net. Fine sand and silt deposits are quite suitable for the creation of a stable anaerobic environment (Richards 2007: 119-120). As such, the swinging motion of the net is similar to a filter (sieve) used for removal of gravel and pebbles from the sand used in construction (Author’s personal experience). In the preliminary monitoring and maintenance programme the team of divers always paid attention in the prevention of damages to the net and measured the sediment deposition. Monitoring by way of visual observation, was made four times within one week after the process of conservation. Thereafter monitoring was made in the aforesaid manner once every two weeks. Monitoring revealed within the first week that sand deposits under the net ranged from 5-15cm. Our MAU Avondster in-situ Data Sheets from fieldseasons 2005-2009 recorded minimum deposition was observed on the starboard side and the maximum was deposited towards the port side. We did not expect to see sand deposits on every part equally. We noticed the port side gained more sand than the starboard. Minimum deposition was observed towards the west corner of the bow section. The mid-ship area was not covered because there was an ongoing excavation on that area. In April 2004 two strips of nets were used to cover the 4 meter space towards the stern section from the galley. After placing the net it was covered with sand immediately because the monsoon season was beginning and there was no time to let the net �fill naturally. We did not try to cover the galley because it stands nearly 5 feet above the sea bed. After the excavation of the mid-ship area, the decision was made to cover the trench through the same system. After the excavation the trench was filled with sand using the water dredge in reverse, and again after the net was laid. Also two strips of net were placed on the trench. During the diving in May to September we noticed the nets were damaged in several places due to the high waves. The nets were loosened and moving from side to side. The nets on the excavation trench were in bad shape. The hull was exposed in this area and the net was torn badly in some places. Especially the places near the wooden parts of the hull. But we were not able to do anything about these issues due to the rough sea conditions. Our MAU Dive Report for October 2004 recorded that this work resumed and the tears were covered with sand bags. The sand is resting on the nets again and the net at the stern area is in good shape. Up to December 23rd 2004 these visual monitoring activities were conducted, together with the excavation, on the end of the stern section. During a period of three months, from October to December, we noted a sedimentation pattern had formed that was conducive to an anaerobic environment. Three days after the end of the Avondster project on December 26th 2004 a strong tsunami wave hit Sri Lanka destroying many coastal areas. The city of Galle was also badly affected and the MAU laboratory and the diving unit were completely destroyed. Luckily no one was hurt because it was a Sunday and the unit was closed. It took more than three months to get-back on to our feet and start work. The MAU building was partly reconstructed and most of the artefacts and equipment that were left were brought to a new building inside the Galle fort. In March 2006 we did our first dive on the Avondster to find out its situation. We were expecting to see more damage on the galley, which was in an unstable situation even before the tsunami and to examine the damage to the nets. The site was completely covered with sand. We were not able to see any wooden parts at the bow section. It was covered with a thick layer of sand, including the edges of the nets. The upper part of the galley was located and the brick structure was well intact. Two cannons and some wooden hull parts were detected at the stern section. The condition of the galley gave us hope for the rest of the wreck. The whole seabed was destroyed with waste and debris that came with the tsunami. A lot of fibreglass (from boats) hung all over the Avondster site. We also noticed few large tree logs on the site that we worried were harmful to the galley. �Figure 2. Location of the covering nets and the control points for monitoring (Drawn by R. Muthucumarana). The day we had our fist dive we had very bad visibility. During the following months we did more diving on Avondster and found out the wreck survived without further damage. The sand layers deposited under and on the net withheld against the tsunami wave firmly and protected the wreck. Forming a system for monitoring As there was no sufficient equipment to do the biological and chemical analysis of the shipwreck we decided to monitor the sediments on the wreck. The sedimentation level was measured manually. In November 2005 four aluminum poles were hammered and fixed vertically around the wreck near the net. Each was 3.5 meters long and had a 2 inch diameter. They were secured at 1.5 meters depth and each pole stood 2 meters above the seabed. Two were fixed near the bow section and two near the stern. Rods were not placed in the center of the shipwreck because it was thought that it would damage the artifacts attached to the vessel. The poles were marked using plastic tape and zip-ties/ty-raps. Zipties/Ty-raps were used to mark 5cm intervals. In order to find the poles more easily during occasions of low visibility, the rods were inter-connected with nylon rope. A diving data sheet was prepared to record the measurements. The monitoring work was begun in November 2005 and is planned to continue through the coming years (once every two months). During the monsoon season this is expected to be difficult and also when the team going on the field work out of the Galle region. �Result Analysis Generally inside the Galle bay there are no seasonable and noticeable deferences in pH level (see Godfrey, Richards and Cha this volume), salinity, water temperature and Oxygen percentage. Also we didn’t have the sophisticated and necessary equipments to measure these things regally. The only topic given attention is sedimentation or its fluctuations. Most of the time anaerobic biological situations are formed due to the thickness of the protective sand layer or direct impacts caused by this. It is generally accepted that an anaerobic biological situation is formed under a sand layer with a minimum of 15 cm coverage (Richards 2007: 116-117). However, this is based on the type of protective layer. For example, a protective layer made of core sand or pebbles, of somewhat large size, is not as stable as a protective layer made of silt or fine sand. The spaces among the large particles circulate oxygen creating a welcoming environment for organisms. As such, not only the thickness of the protective layer but the composition and the steadiness were also considered. Table 1.Sedimentation levels taken from the measuring poles from 2005- 2009 (MAU Avondster In-situ Data Sheets 2005/2009) Pole Pole Pole Pole Date B C D A 2005/12/04 2006/04/26 2006/10/27 2007/03/30 2007/11/04 2008/04/30 2008/12/16 2009/04/08 2009/10/12 9cm 17cm 11cm 15cm 13cm 18cm 4cm 20cm 26cm 13cm 22cm 16cm 23cm 19cm 28cm 14cm 24cm 32cm 15cm 28cm 24cm 33cm 36cm 46cm 42cm 55cm 63cm 23cm 34cm 32cm 41cm 48cm 56cm 44cm 71cm 92cm �Chart 1Sedimentation levels taken from the measuring poles from 2005- 2009 (MAU Avondster In-situ Data Sheets 2005/2009). At the time when the monitoring system was established in November 2005; a considerable level of erosion had occurred towards the starboard side of the shipwreck. At the time, we start the monitoring a 40-50 cm sand mound was observed on the net along the port side hull. This sand mound was recorded as established up to December 2009 when monitoring work ceased. Data extracted from the aforementioned diving data sheets are given below. The sediment level on the net or on the middle of the wreck was taken between A-C and B-D poles with a bubble-level which was attached to a string. Table 1 summarizes the data collected. �Chart 2a and b. Measurements taken from the poles and from the sand mound near the port side hull 2005- 2009 (Dive reports from 2005/2009) Conclusion Preserving organic wreckage in tropical and shallow seas with high oxygen concentration and temperature is a challenge. In these conditions the wrecks can vanish without any trace (Manders, et al. 2004:1253). There is no 100% reliability with regard to the success of the in-situ preservation even after 8 years of process. The wreck is still open to the risk of natural, biological and human factors. To some extent the wreck is protected from looters and fishermen. Before covering the wreck, after the monsoon activities, there were a lot of loose artefacts moving on the seabed around the wreck. Now that situation is fully controlled. Deep in the mid-ship area within an excavation trench we found a thick layer of steady protective silt with well protected wooden/organic remains. The trench is now fully filled with sand and may have a stable anaerobic environment. The effectiveness of the polypropylene net covering was quite successful. The edges that can be found in some places are still in good strength, so we recommended this type of net we used in other tropical regions attempting in-situ preservation projects. By using the 2 meter wide stripes to cover the wreck the advantage is ease of access to excavate or re-open the wreck site, or a part of a site. We can easily remove the sand by a water dredge and uncover the exact area we seek by removing the associated strip. There is no need to cut or remove the whole net. �Overall we can report that the port site of the wreck’s hull is relatively safe and some parts of the starboard side is exposed, especially during the monsoon season. Bibliography Amendment No. 24 1998 Bonke, H., Parthesius, R., Ketel, C.V.D.P., 2007 Carpenter, J., Richards, V., 1996 Green, J., Parthesius, R., 1997 Law No. 19 1940 Manders, M.R., Chandraratne, W.M., Dayananda, A.M.A., Muthucumarana, R., Weerasena, K.B.C., Weerasinghe, K.D.P., 2004 Manders, M.R., Gregory, D.J., Rechards, V., 2008 Parthesius, R., Millar, K., Devendra, S., Green, J., 2003 Parthesius, R., Millar, K., Devendra, S., 2004 Parthesius, R., Millar, K., Jeffery, B., 2005 Prott, L.V., 2003 Amendment No.24 of Antiquity Ordinance No.19 1998. Artifacts Catalogue Avondster Site, 1998-2004, Centre For International Heritage Activities, The Netherlands. Conservation in Galle, interim report of the Galle Harbour Project. "Galle - A Port City In History", in Papers from the seminar Australian Centre For Excellence in Maritime Archaeology. Antiquity Ordinance No.19 of 1940. “The Physical Protection of a 17th century VOC shipwreck in Sri Lanka”, in Current Science, Volume, 86. No.09. India. In-situ Preservation of Archaeological Sites Underwater An Evaluation of Some Techniques, The Netherlands. Avondster Project Report 2001-2002, Amstradam Historisch Museum, The Netherlands The Mutual Heritage centre, Sri Lanka. Avondster Project. Galle 2001-2004, Mutual Heritage Cooperation Sri Lanka, The Netherlands, Australia. "Preliminary Report on the excavation of the 17th century Anglo - Dutch East- Indiaman Avondster in bay of Galle Sri Lanka", in The International Journal of Nautical Archaeology. "Finishing The Interrupted Voyage", in Papers of the UNESCO Asia Pacific workshop on the 2001 convention on the protection on the underwater cultural heritage, Institute of �Richards, V., Carpenter, J., Parthesius, R,. 2007 Art and Low, UNESCO. Avondster conservation survey report, Department of Materials Conservation, Western Australian Maritime Museum, Excavation report of the VOC ship Avondster, Special Publication No.1, Centre For International Heritage Activities, The Netherlands. "In-situ Monitoring and Stabilisation of the James Mathews Shipwreck site", in Proceeding of the 10th ICOM Group on Wet Organic Archaeological Materials Conference, Amsterdam. Richards, V., Godfrey, I., Blanchette, R., Held, B., Gregory, D., Reed, E., 2007 Weerasinghe, K.D.P., The Physical Protection of The Avondster Wreck Site, Manders, M., Attachment 02, Maritime Archaeology Unit, Sri Lanka. 2003 Dive reports, 2005 to Dive reports, Maritime Archaeology Unit, Fort, Galle. 2009 � Document A resource containing textual data. Note that facsimiles or images of texts are still of the genre text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource In-situ preservation In Tropical Seas: Case Study on the Avondster Shipwreck Subject The topic of the resource Session 7 Preservation and conservation of wet archaeological materials and site management Description An account of the resource The VOC ship Avondster sunk on 2nd July 1659 when anchoring near the beach in Galle Bay, geographically located in the southern part of Sri Lanka. She was re-discovered in 1993 and subjected to a series of research projects including excavation in the bow, stern and mid-ship areas. Due to construction work in Galle Harbour it was important to protect the shipwreck in situ. The environment in the Galle Bay badly affected the wreck site and it was a big challenge to overcome all the harmful factors that were likely to damage the remains of Avondster. In order to preserve Avondster a plastic net was introduced as a protective layer over the wreck site. This was monitored constantly throughout and after the research period. The protective layer was used over the fragile timbers for nearly 8 years before a violent tsunami hit Galle Bay in December 2004. Despite the serious damage caused on the land by the tsunami, it had less effect on the site and the covering-plastic net was still intact. From that time on monitoring has continued every two months. This paper discusses in detail the present condition of the in situ protection and its validity as a preservation technique in the conditions found in tropical seas. Creator An entity primarily responsible for making the resource Chandraratne Wijamunige Date A point or period of time associated with an event in the lifecycle of the resource November 2011 Asia-Pac Session 7 https://apconf-much.org/proceedings/files/original/f922292752e79d078ebe19de938e1369.pdf 4e1024ff4569424e1760c102dc03a31f PDF Text Text Bottom Trawling and the Damage to Underwater Cultural Heritage: An Overview of the Destruction and Possible Steps Forward Charlotte Jarvis (The Ocean Foundation, Threats to Our Ocean Heritage Project Leader) ABSTRACT Trawling has long been regarded as a damaging practice and marine ecologists have lobbied for restrictions. The damage to Underwater Cultural Heritage (UCH), however, has received less attention, though it is just as consequential. This paper looks at UCH damage case studies and the impacts of heritage loss and then suggests steps forward. The case studies in the paper will include the damage to UCH across the ocean and in the Mediterranean and Black seas. Shipwrecks are as much part of the marine landscape, and thus of importance to ecologists, as they are to the cultural, historical landscape. Yet nothing has been done to seriously limit trawling and protect the underwater cultural landscape and archaeological impacts and data are missing from biological reports on the process. No underwater policies based on cultural preservation have been formulated to manage offshore fishing. There is a preferred policy for in situ preservation in the 2001 UNESCO Convention on the Protection of Underwater Cultural Heritage and some practical measures for site managers to address the threats from bottom trawling but if in situ preservation is to be supported, more needs to be done. Moorings can be added and shipwrecks, if left in place, can become artificial reefs and places for more artisanal, sustainable hook-and-line fishing. However, what is needed most is for states and international fishing organisations to ban bottom trawling at and around identified UCH sites, as has been done for some seamounts. This work is part of the Threats to Our Ocean Heritage project, a UN Decade for Ocean Science approved Action discussing this issue of Trawling, Deep Seabed Mining, and Potentially Polluting Wrecks. The expected results include ocean literacy that increases awareness of the issue to a wider range of stakeholders including international organisations, states, and institutions with the authority to effectuate change. Keywords: Underwater Cultural Heritage; Bottom Trawling; Maritime Archaeology List of abbreviations Exclusive Economic Zone (EEZ) National Research Council (NRC) Nautical Miles (nm) Remotely Operated Vehicle (ROV) Underwater Cultural Heritage (UCH) United Nations Educational, Scientific and Cultural Organization (UNESCO) List of figures Figure 1: A beam trawler and an otter trawler. Figure 2: A diver examining fishing debris on a shipwreck. Figure 3: The intensity of trawling around the globe, focused in coastal regions in tonnes per kilometres squared. Figure 4: Evidence of fishermen respecting prohibited zones in Southwest Turkey. INTRODUCTION Trawling has been recognised as a catastrophically damaging practice with lasting negative consequences on seabed ecology and marine life. Less well known though are the dramatic effects trawling has also had on maritime archaeology sites. Although legislation limiting trawling may help biological communities rebound, the archaeological material lost can never be recovered. Restrictions must be passed as soon as possible to prevent further material and heritage destruction. 1 �Bottom, or beam, trawling refers to the practice of pulling a net behind a boat to catch fish. Trawling grew from a need to keep up with declining fish stocks and developed further with technological changes and increased demands, though fishermen constantly complained about the problems in overfishing it created. All three trawling revolutions—invention, mechanisation, and later deep-water expansion—have been met with controversy and pushback from the public and conservationists alike (Roberts 2008, 133). Yet nothing has been done to seriously limit the practice and protect the submerged cultural landscape. Crucially, archaeological impacts and data are also missing from biological reports and published articles on the practice. Trawling developed from the practice of fishing with a net, but that older style was more controlled. Fishermen knew what they were going to pull up each time and rarely had surprises. With bottom trawling, nets are weighted to keep them low along the sea floor and a large beam on deck spread the nets wide to increase catch. This practice of dragging nets along the bottom of the sea, according to historian Jeffery Bolster (2012), redefined the fisherman’s relationship with the fish and it became an exploitative relationship. The practice has enabled humans to both exploit the sea and destroy their own history at the same time. There is no doubt that trawling has decimated fish stocks globally and brought hardship on fishing communities. Today’s boats must work an estimated 17 times harder than in the past because there are literally fewer fish in the sea (Roberts 2012, 44). With one pass by a trawler, boulders can be displaced, large epifaunal invertebrates removed and damaged, and sediment re-suspended (Freese et al. 1999, 119). Structural components of fish habitats are removed, and biodiversity is lost. The effects have been likened to clear cutting a forest, or strip mining. This paper serves as a call for action to address the threats to our ocean heritage from the long history of the destructive activities of bottom trawling. Calum Roberts (2012, 6) writes that the ‘impacts [of trawling] are discussed in isolation and different meetings and by different people who never quite see the picture’. He is referring to different people within the marine scientific fields such as those focused on fishery sciences or pollution. His point holds true, though, with a group of people many do not consider to be ocean heritage professionals: maritime archaeologists or underwater cultural heritage professionals. Although efforts to illustrate sustainability in seafood, such as the Marine Stewardship Council stamp, may attempt to show safe fishing practices, one can never be sure of the wider harm being done, especially to UCH. Some conservationists, including Roberts (2008, 348), argue that trawling should be limited to locations where it does not harm the ecological landscape. Maritime archaeologists and marine ecologists need to communicate and work together to lobby for moratoria on trawling. Shipwrecks are as much part of the marine landscape, and thus of importance to ecologists, as they are to the cultural and historical landscape. History of Trawling First Revolution As far back as 1376, the English parliament was already worried about the destructive nature of trawling to fish populations and habitats, noting that trawling ‘runs so heavily and hardly over the ground when fishing that it destroys the flowers of the land’ and takes so many fish ‘to the great damage of the commons and the destruction of the fisheries’ (Petition by the Commons to King Edward III, 1376 seen in Bolster 2012, 235). Trawling in Europe continued sporadically through the medieval and early modern periods until the early nineteenth century when the industrial revolution pushed trawling technology further. 2 �Second Revolution By 1840, fishermen, using sail power, were already noticing depleted stocks, so changes developed out of a necessity to compensate for a declining catch. Enter steam-powered vessels, which could gather four times more fish per catch than a sailing vessel (Bolster 2012, 237). These vessels were not limited by weather and had the strength to power nets with chain reinforcements on the seafloor. This, by the end of the nineteenth century, enabled the transition to the otter trawl, where two ‘doors’ are used to open the nets easily, accommodating larger nets (NRC 2002, 14). Figure 1: A beam trawl (top) and otter trawl (bottom). (Source: Ecomare, licensed under the Creative Commons Attribution-Share Alike 4.0 International) Third Revolution Arguably the most detrimental technological advance came after World War II. Factory-sized, freezer-equipped trawlers appeared and changed fishing practices. These vessels had stern ramps to accommodate larger nets and brought quick-freeze facilities, storage, and fishmeal processing machines onboard. Trawling spread to the deep sea, spearheaded by the Soviet Union but quickly growing into a global industry. The 1950s and 1960s saw the rise of echo sounders and access to areas beyond the reach of shallow trawls. But these new fishing grounds often had rough seafloors that shredded the nets. In response, an innovation was born that significantly increased the destructive power of the trawls. ‘Rockhopper gears’, up to one metre in diametre and weighing hundreds of kilos, are massive steel rubber rollers and chains attached to trawl nets, enabling them to grate flat over the seafloor, destroying everything in their path (Atkinson 2012, 16) 3 �Commercial fishermen now had the technology to send their boats out for longer, fish further away, and fish faster with larger nets (NRC 2002, 12). Eastern European nations took this to a new level, creating ‘floating towns built for the sole purpose of processing marine life into food’ (Roberts 2008, 189). Biologically productive deep seamounts became the new targets and using sonar, vessels could trawl through a large group of fish taking in 50 to 60 tons in a few minutes (Roberts 2008, 291). Today, trawling has grown to previously unimaginable rates. The nets used cut paths through the seafloor at least 100 metres wide and four stories tall, pulling in fish at staggering and unsustainable rates. Many nets are made of synthetic materials which do not break easily when snagged, allowing for higher powered vessels (Brennan 2016, 158). These nets also make up the largest portion of marine debris and plastic pollution in the ocean. With improved gear and electronics, vessels can map the seafloor, fish very close to bottom features, drag nets over rougher seafloor than before (Dorsey 1998, 2), and decimate fish populations and UCH sites across the ocean. This destruction of natural heritage has been well documented and there are some promising studies in UCH damage from trawling that will be explored next. Figure 2: A diver examines debris left from fishing gear in the Stellwagen Bank Marine Sanctuary, a nationally protected area in the United States that allows trawling and fishing within its borders. Almost all wrecks in this protected area have been impacted by trawling (Marx 2010) (Image source: National Oceanic and Atmospheric Administration, https://stellwagen.noaa.gov/protect/shipwrecks.html). 4 �CASE STUDIES Coastal Trawling and the Continental Shelf Coastal seas are some of the most ecologically productive areas with delicate plants and marine life and complex ecological systems. A 2021 report found that trawling is the most intense in the territorial (12 nautical miles (nm) offshore) seas of coastal states (Steadman et al. 2021, 5; Pauly, Zeller, and Palomares 2020) and is illustrated in figure 3. Figure 3: The intensity of trawling around the globe, focused in coastal regions in tonnes per kilometre squared (Source: Pauly, Zeller, Palomares 2020, printed under Creative Commons Attribution Non-Commercial 4.0 International License). Coastal trawling is also particularly destructive to UCH, since it is where most known wrecks are located (Atkinson 2012, 11). For example, of the more than 100 shipwrecks in Turkish waters, 16 were observed within trawling boundaries in the Aegean Sea to quantify damage. Researchers found these wrecks with trawl scars running across the site (Brennan et al. 2012). Off the coast of Northern Italy, the Mercure wreck was discovered after historic material was found in a trawl net, and further research showed that trawling nets had spread the vessel and is artefacts across an area of 100 meters (Atkinson 2012, 53). Many wrecks in the Asia Pacific region lie in areas of heavy trawling activity and the wreck timbers have already been damaged. For example, Sten Sjostrand identified 15th- and 16th-century wrecks off the coast of Malaysia, and both were damaged by the time he returned even though the 15th-century wreck once stood 1.8 metres off the seabed (Atkinson 2012, 49). Three kilometres west of Ko Si Chang, Thailand, the Chang I wreck was found when trawl nets stuck to it during a survey in 1981, and archaeological survey markers were left behind. By the time archaeologists revisited the site in 1983, the markers were missing, likely sheared off by trawl gear (Green et al. 1986, 108). Off the coast of New South Wales, Australia, many wrecks have been impacted by scallop dredgers including the City of Launceston, Euralba, Eleutheria, the Isis, and the Lady Darling (Atkinson 2012, 53). 5 �It is not just shipwrecks being destroyed, though. Rising sea levels have put many prehistoric landscapes under coastal waters today. Among the sites worst affected by trawlers is Doggerland, a 30,000-square-kilometre area inhabited during the Mesolithic period (8,000 years ago), which is now under the waters of the North Sea. Hundreds of stone tools have been dragged up over the centuries as it has been bulldozed by trawlers (Atkinson 2012, 68). This area is a valuable example of a site that is both a paleo seascape as well as a site of past human inhabitation. Also in the North Sea, near Brown Bank, Dutch fishermen found items dating to 7200-6000 BC and near Colijnsplaat, Netherlands, when Roman alter stones were dragged up. Even a Neanderthal skull fragment has been found in this area. Off the coast of England, a Saxon period longshore post was visible at low tide, with trawl damage obvious. There are many examples of this in North America too. As a result of deglaciation and isostatic uplift, many sites of the First Americans are now covered by water. Fishermen off the coast of New England have reported findings of tools from the Middle Archaic period and off Virginia a mastodon skull and a stone biface were discovered (Atkinson 2012, 55, 56, 64, 66). Submersible surveys have also discovered shipwrecks that have already been damaged by trawlers on the Continental Shelves (12nm to 200nm from the coast and >200 m deep). In the Bulgarian Black Sea, trawling methods reach down about 100 m on the shelf (limit of trawling depth here) to catch sea snails, clams, and other benthic species and have been a significant practice for decades, unregulated by the government (Prahov et al. 2021, 748 and 749). Since 2010, surveys have been conducted to monitor the damage to wrecks, but no adequate prevention measures have been taken (Prahov 2021, 749). The issue of heritage destruction by trawling is also important to the Asia-Pacific Region because traditionally, trawling studies with UCH have focused on European and North American waters, even though roughly 50 per cent (over the last decade of available data) of all bottom trawled fish come from the continental shelf/EEZs of Asian nations or the foreign fleets of Asian countries (Steadman et al. 2021, 5). Deep Sea Trawling and The High Seas As technology improved and moved further out to the seamounts in the deep sea, more UCH sites must be protected from trawling. The deep-water sites are further from anthropocentric damage and valuable resources due to their in-accessibility. Remotely Operated Vehicle (ROV) technology has allowed previously impossible deep-sea (more than 200 m deep) exploration and has revealed beautiful, complex habitats. Stunning corals and rich communities are now visible, yet most already showed trawl scars and broken fishing gear. Today’s trawls can reach depths of 2000 m and everywhere scientists look they see evidence of trawling destruction and no evidence of recovery (Victorero et al 2018, 2). There is also evidence of trawl damage on deep-water wrecks off the coast of Turkey along its Mediterranean, Aegean, and Black Sea shores (Brennan et al 2016). Michael Brennan’s (et al 2012, 55) work in studying wrecks in Aegean Turkish waters below diving depth, showcases the damage trawling can do and the high stakes of what is being lost. The studied sites range in depth from 82410 m deep and cover centuries of history (Brennan et al 2012, 64). In the Black Sea, Ereğli E, one of the oldest deep-water wrecks yet discovered, could have been one of the most significant wrecks ever found in the area, but by the time it was found in 2011, it had already been nearly destroyed by trawling (Brennan et al 2016, 84). In the Pacific, though New Zealand is the only main participant of deep-water trawling over seamounts in the high seas of the South Pacific, there are a handful of active vessels in the North and the existing and potential future damage done must be discussed (Thomas 2022). There are hundreds of years of history preserved on the Pacific seafloor and immeasurable quantities of intangible cultural heritage that need to be protected. 6 �FRAMEWORK The case studies and research show how bottom trawling is not only a threat to our natural heritage but are clearly a major threat to UCH. The stories of our societies and our ancestors are wrapped in intangible connection with the ocean and captured on the seafloor as artefacts, shipwrecks, and remains of those lost or buried at sea. Marine global heritage has largely been based on natural heritage. However, UCH is also ocean heritage and must be respected in the same way. Cultural heritage and natural heritage are intertwined when it comes to the ocean. UCH can support ecological marine biodiversity and helps boost sea connectivity. Natali Pearson and Benjamin Thompson (2023, 3) argue that it is beneficial for sites with high UCH and high natural heritage to cooccur and be used strategically together. Over time, shipwrecks come into equilibrium with the marine environment around them and become part of the benthic topography (Brennan 2016, 172). Trawling rapidly destroys this equilibrium, which often has been balanced for centuries (Brennan et al. 2013, 99). Shipwrecks often function as artificial reefs providing habitats, shelter, and adding hard materials to an otherwise soft seafloor. Michael Brennan’s (2016, 172 ; Krumholz and Brennan 2015) research on the Knidos shipwrecks along the Aegean coast of Turkey indicates that lightly trawled ancient wrecks with structures on the seafloor still exhibit more fish population and biomass than heavily trawled wreck sites with little or no structure remaining. Through this process of ‘spill over’, protected shipwrecks can help increase the strength of surrounding fish stocks. Shipwrecks can be as indispensable to the seafloor ecology as a natural coral reef or seamount. Thus, shipwrecks should not be viewed solely in a cultural significance context; they are part of the natural ocean landscape as well as our cultural history. RESULTS The results of this paper are a suggestion of steps forward. Underwater policies formulated to manage offshore fishing based on cultural preservation are lacking. Some trawling restrictions were placed after backlash in the 1990s when ecologists and fisheries experts, well aware of the dangers of trawling, lobbied for more restrictions. This research and advocacy for regulation are a good start. There is a preferred policy for in situ preservation by archaeologists and historians codified in the 2001 UNESCO Convention on the Protection of Underwater Cultural Heritage but some practical measures for site managers to address the threats from bottom trawling are needed. If in situ preservation is to be supported, moorings should be added for shipwrecks that are destinations for ecocultural tourism. As artificial reefs they may be appropriate places for more artisanal, sustainable hook-and-line fishing. However, what is needed most is for states and international fishing organisations to ban bottom trawling at and around identified UCH sites, as has already been done for some seamounts. Most importantly, trawling damage should not be allowed as a justification for salvage. The author recognises that these results cannot be achieved without the voice and support of the fishing community. Wrecks, however, also present problems to fishermen. When nets snag, gear is lost or ruined and can be costly to replace. Shipwrecks can also endanger the lives of those onboard vessels. In Britain from 1976 to 2005 around 16 vessels capsized after gear was snagged on obstructions and many lives were lost (Atkinson 2012, 3). Although some shipwreck sites have only been found because of fishermen’s reports, there is no requirement for fishermen to do so. Collaboration and partnership between archaeologist and fisherman is needed and archaeologists must understand the context fishermen operate in to communicate effectively (Brennan et al. 2012, 62; see Figure 4). 7 �Figure 4: Evidence of fishermen respecting prohibited zones in Southwest Turkey: dark grey area shows a zone where trawling is prohibited, dots show visible trawl scars on the seabed (Source: Brennan et al. 2012, 62 reprinted with permission). What we do with trawling can pave the way for other important ocean exploitation. Climate change will continue to threaten our oceans (for example, sea-level-rise sinking previously terrestrial sites) and we know ecologically why it is important to protect the ocean. While there are many unknowns in deep sea biodiversity and ecosystem services, what we do know clearly points to vast and far-reaching damage. In other words, we know enough from existing trawling damage that tells us we should stop similar practices, like seabed mining. We cannot predict undiscovered historical significance. Trawling is a clear and present threat not only to fish populations and habitats, but also to submerged cultural landscapes. There should not be a choice between humans and the natural world. Restrictions such as the options above, must be passed as soon as possible to prevent further material and heritage destruction. Acknowledgements Thank you to The Ocean Foundation, The Lloyd’s Register Foundation Heritage and Education Centre, ICOMOS-ICUCH, and Ocean Decade Heritage Network for their support of this paper and the Threats to Our Ocean Heritage project. Thank you to Mark Spalding, Ole Varmer, Alexandra Refosco, Michael Brennan, Jim Delgado, Louise Sanger, and Ben Ferrari for their help developing the ideas that are reflected here. Thank you to Claire Zak and Sheri Kapahnke for hosting a session and a dynamic discussion on Coastal UCH sites at the EAA meeting in 2022 that sparked the idea to pursue this research. 8 �Bibliography Atkinson, Christopher Michael. “Impacts of Bottom Trawling on Underwater Cultural Heritage”. Master’s Thesis, Texas A&M University, (2012). Bolster, W. Jeffrey. The Mortal Sea: Fishing the Atlantic in the Age of Sail. Cambridge, Mass. London: Belknap Press of Harvard Univ. Press, 2012. Brennan, Michael L., Robert D. Ballard, Chris Roman, Katherine L.C. Bell, Bridget Buxton, Dwight F. Coleman, Gabrielle Inglis, Orkan Köyağasıoğlu, and Tufan Turanlı. “Evaluation of the Modern Submarine Landscape off Southwestern Turkey through the Documentation of Ancient Shipwreck Sites.” Continental Shelf Research 43 (2012): 55–70. Brennan, Michael L., Dan Davis, Chris Roman, Ilya Buynevich, Alexis Catsambis, Meko Kofahl, Derya Ürkmez, J. Ian Vaughn, Maureen Merrigan, and Muhammet Duman. “Ocean Dynamics and Anthropogenic Impacts along the Southern Black Sea Shelf Examined through the Preservation of Pre-Modern Shipwrecks.” Continental Shelf Research 53 (2013): 89–101. Brennan, Michael L. “Quantifying Impacts of Trawling to Shipwrecks.” In Site Formation Processes of Submerged Shipwrecks, edited by Mathew E. Keith, 157-178. Gainesville: University Press of Florida, 2016. Brennan, Michael L., Dan Davis, Robert D. Ballard, Arthur C. Trembanis, J. Ian Vaughn, Jason S. Krumholz, James P. Delgado, et al. “Quantification of Bottom Trawl Fishing Damage to Ancient Shipwreck Sites.” Marine Geology 371 (2016): 82–88. Freese, Lincoln, Peter J. Auster, Johnathan Heifetz, and Bruce L. Wing. “Effects of Trawling on Seafloor Habitat and Associated Invertebrate Taxa in the Gulf of Alaska.” Marine Ecology Progress Series 182 (1999): 119–26. Green, Jeremy, Rosemary Harper, and Vidya Intakosi. “The Ko Si Chang One Shipwreck Excavation 1983-1985. A Progress Report.” International Journal of Nautical Archaeology 15, no. 2 (1986): 105–22. Krumholz, Jason S., and Michael L. Brennan. “Fishing for Common Ground: Investigations of the Impact of Trawling on Ancient Shipwreck Sites Uncovers a Potential for Management Synergy.” Marine Policy 61 (2015): 127–33. Marx, Deborah. “Fishing Threatens Historic Shipwrecks.” INA Quarterly 36(4) (2010): 8. National Research Council (U.S.) (NRC), ed. Effects of Trawling and Dredging on Seafloor Habitat. Washington, D.C: National Academy Press, 2002. Pauly, Daniel, Zeller, Dirk, Palomares, Deng. Editors. Sea Around Us Concepts, Design and Data, 2020. seaaroundus.org. Pearson, Natali, and Benjamin S. Thompson. “Saving Two Fish with One Wreck: Maximizing Synergies in Marine Biodiversity Conservation and Underwater Cultural Heritage Protection.” Marine Policy 152 (2023): 105613. Prahov, Nayden, Bogdan Prodanov, Kalin Dimitrov, and Kiril Velkovsky. “The Negative Impact of Human Activities on Underwater Cultural Heritage: Case Studies from the Bulgarian Black Sea Littoral.” (2021): 743-750. Roberts, Callum. The Unnatural History of the Sea. Washington: Island Press, 2008. Roberts, Callum. The Ocean of Life: The Fate of Man and the Sea. New York: Viking, 2012. Steadman, Daniel, John Thomas, Vanessa Villanueva, Forrest Lewis, Daniel Pauly, M.L. Palomares, Nicolas Bailly, et al. New Perspectives on an Old Fishing Practice: Scale, Context and Impacts of Bottom Trawling, 2021. Thomas, Karli. “New Zealand’s Bottom Trawling Isolation Continues in the South Pacific.” Deep Sea Conservation Coalition, September 29, 2022. https://savethehighseas.org/2022/09/29/new-zealands-bottom-trawling-isolationcontinues-in-the-south-pacific/. Victorero, Lissette, Les Watling, Maria L. Deng Palomares, and Claire Nouvian. “Out of Sight, But Within Reach: A Global History of Bottom-Trawled Deep-Sea Fisheries From >400 m Depth.” Frontiers in Marine Science 5 (2018). 9 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource 2023 Session 13: Major Threats to Underwater Cultural Heritage Subject The topic of the resource Papers presented at Session 13 of the 2023 Asia Pacific Regional Conference on Underwater Cultural Heritage Description An account of the resource Session 13 papers Creator An entity primarily responsible for making the resource Asia Pacific Regional Conference on Underwater Cultural Heritage Publisher An entity responsible for making the resource available The Museum of Underwater Archaeology Date A point or period of time associated with an event in the lifecycle of the resource November 2023 Rights Information about rights held in and over the resource Asia Pacific Regional Conference on Underwater Cultural Heritage Language A language of the resource English Rights Holder A person or organization owning or managing rights over the resource. Asia Pacific Regional Conference on Underwater Cultural Heritage Document A resource containing textual data. Note that facsimiles or images of texts are still of the genre text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Bottom Trawling and the Damage to Underwater Cultural Heritage: An Overview of the Destruction and Possible Steps Forward Description An account of the resource Trawling has long been regarded as a damaging practice and marine ecologists have lobbied for restrictions. The damage to Underwater Cultural Heritage (UCH), however, has received less attention, though it is just as consequential. This paper looks at UCH damage case studies and the impacts of heritage loss and then suggests steps forward. The case studies in the paper will include the damage to UCH across the ocean and in the Mediterranean and Black seas. Shipwrecks are as much part of the marine landscape, and thus of importance to ecologists, as they are to the cultural, historical landscape. Yet nothing has been done to seriously limit trawling and protect the underwater cultural landscape and archaeological impacts and data are missing from biological reports on the process. No underwater policies based on cultural preservation have been formulated to manage offshore fishing. There is a preferred policy for in situ preservation in the 2001 UNESCO Convention on the Protection of Underwater Cultural Heritage and some practical measures for site managers to address the threats from bottom trawling but if in situ preservation is to be supported, more needs to be done. Moorings can be added and shipwrecks, if left in place, can become artificial reefs and places for more artisanal, sustainable hook-and-line fishing. However, what is needed most is for states and international fishing organisations to ban bottom trawling at and around identified UCH sites, as has been done for some seamounts. This work is part of the Threats to Our Ocean Heritage project, a UN Decade for Ocean Science approved Action discussing this issue of Trawling, Deep Seabed Mining, and Potentially Polluting Wrecks. The expected results include ocean literacy that increases awareness of the issue to a wider range of stakeholders including international organizations, states, and institutions with the authority to effectuate change. Creator An entity primarily responsible for making the resource Charlotte Jarvis Publisher An entity responsible for making the resource available The Museum of Underwater Archaeology Date A point or period of time associated with an event in the lifecycle of the resource 2023 Language A language of the resource English Bibliographic Citation A bibliographic reference for the resource. Recommended practice is to include sufficient bibliographic detail to identify the resource as unambiguously as possible. Jarvis, Charlotte . 2023. “Bottom Trawling and the Damage to Underwater Cultural Heritage: An Overview of the Destruction and Possible Steps Forward.” Edited by Jennifer Craig, Jay Mok, T. Kurt Knoerl, and Ole Varmer. In Proceedings of Fifth Asia Pacific Regional Conference on Underwater Cultural Heritage: Gwangju, The Republic of Korea, November 13-18 2023. The Museum of Underwater Archaeology. URL: https://apconf.omeka.net/exhibits/show/apconfproceedings/item/1904 Asia-Pac Session 13 2023 https://apconf-much.org/proceedings/files/original/779bfc67e84459b29291b623f43572d6.jpg 1e358f69411f0e41a80cf9ca8e430a5a Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Poster Session 2014 Description An account of the resource Posters presented at the Asia-Pacific Regional Conference on Underwater Cultural Heritage Still Image A static visual representation. Examples of still images are: paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type "text" to images of textual materials. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Boats of Central Vietnam: Maritime ethnography and European archives Description An account of the resource Poster presented at the 2014 Asia-Pacific Regional Conference on Underwater Cultural Heritage Creator An entity primarily responsible for making the resource Charlotte Minh Ha PHAM Date A point or period of time associated with an event in the lifecycle of the resource 7/9/2014 Asia-Pac Poster 2014