On a one off NAS course, a team of archaeologists from St Andrews University recently partnered with the University of Dar es Salaam to teach Tanzanians how to research and preserve their local underwater heritage. These researchers, Edward Pollard, Richard Bates, Ellie Graham, and Elgidius Ichumbak, tell their story below.

Students learning to recognise and interpret unusual rocks on the reef at low tide.

In March, the Nautical Archaeology Society supported Underwater Recorder and Surveyor Skills Days in the western Indian Ocean in Tanzania involving the Universities of Dar es Salaam and Saint Andrews funded by Scottish Funding Council. The course took place at the UNESCO World Heritage Site of Kilwa Kisiwani, one of the most important medieval sultanates along the east African coast. Tanzania is part of the Swahili Coast that played an important commercial role exporting commodities such as mangroves, gold, ivory, cloves and slaves, as well as importing cloth, glass, beads, porcelain and incense. This trade along the east coast of Africa is recorded in Classical texts written in Egypt such as Ptolemy’s Geographia and the sailor’s handbook to the Red Sea and beyond called Periplus of Erythrean Sea. Sailing was helped by reliable seasonal monsoon winds and, from around the 7th century, a noticeable increase in artefacts can be found in East African ports such as in the Lamu Archipelago, Malindi and Kilwa that originated in China, Arabia and India.

Although there is earlier evidence dating back to the Middle Stone Age, the main port of Kilwa grew from a fishing and iron-working community at the end of the 1st millennium AD. Kilwa Kisiwani means ‘Kilwa at the island’ in Swahili and is situated within a mangrove-fringed submerged estuary or ria, protected from the Indian Ocean by the coral reefs and raised limestone cliffs. The Kilwa Sultanate was established in the 11th century issuing coins for its expanding trade but excavations and conservation efforts within the settlement in the 1950s and 60s recorded an increase in wealth in the late 13th to 14th century. This was when Kilwa controlled the gold trade that reached the coast at Sofala in modern Mozambique. This wealth is reflected in the surviving architecture though often overgrown and eroding at Kilwa including the domed Great Mosque and the palace of Husuni Kubwa. A Kilwa copper coin has been found inland at Great Zimbabwe where the gold was mined. The Moroccan traveller Ibn Battuta visited Kilwa in 1331, and arriving pilgrims would have been attending one of the largest mosques in Sub-Saharan Africa.

Using the planning frame on the harbour seabed.

The Portuguese led by Vasco da Gama made Kilwa pay tribute in 1502, which resulted in a prominent fort in 1505 overlooking the harbour known to the local people as the Gereza (Swahili for prison, ironically from the Portuguese ingreja meaning a church). After this, Kilwa declined as it lost control of the gold trade, along with suffering attacks by inland and other coastal groups though there was some resurgence in the 18th century involving slave trading with French coffee plantations in Reunion and Mauritius. It is a relatively quiet place today with occasional tourists though cargo-carrying, ferry and fishing vessels can be observed including dug-out canoes, some with outriggers, and dhows with lateen sails.

This coast has unrecorded evidence of shipwrecks and other maritime technology but archaeological research has been limited, which the Nautical Archaeology Society training is starting to alleviate. The aims were to give locals experience of recognising, recording, conservation and reporting cultural features on the seabed so that they would use the skills elsewhere so a marine sites and monuments record can be developed for Tanzania. All this information can be used to encourage Tanzania and other countries in the region to sign the UNESCO Convention on the Protection of the Underwater Cultural Heritage. Furthermore, the team wanted to start investigating how archaeological sites and coastal communities are affected by climate change as a result of the surrounding dynamic environment along with anticipated future severe storms and sea level rise. Drones were used to record and model the present state of eroding palaces, fort, mosques and intertidal shipwrecks. A day of heritage celebration was held on Kilwa Kisiwani inviting island and mainland schools and communities for traditional games, tours of the ruins, and a barbeque of banana, goat and fish.

Students taking part in lectures in the classroom.

Students came from the Zanzibar Institute of Marine Sciences, Kilwa Tourism Information Centre, Ministry of Natural Resources and Tourism, University of Dar es Salaam, and Tanzania Marine Parks and Reserve Unit. During the course, the team practiced offsets on the intertidal zone in an area of volcanic black basalt, an exotic rock on the coral coast that would appear to be the ballast of a ship that had run aground on the fringing reef. This site also includes fragments of storage jars from southern Iran dated to the late 8th to 10th century. We then repeated the exercise on an underwater site up around 10m deep that presented challenges in visibility and strong currents. This appears to have been an anchorage with a stone anchor that has been dated to the 11th century AD at Siraf in the Persian Gulf. Pottery finds from another ballast spread near the anchor range from the 13th to the 16th century. On the last day of underwater fieldwork, it was decided after careful recording on the seabed to lift two artefacts for training in conservation and further study of date, purpose and origin at the University of Dar es Salaam. It is hoped that future expeditions can expand this training and research revealing the worldwide significance of this important maritime culture.

To continue reading about this research, find their article in the IJNA here.

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