From issue: May 2002

Snatching Knowledge from the Sea

by Chris Jacomb & Rachel Darmody

Investigation of a South Otago archaeological site threatened by coastal erosion has yielded valuable information about early Maori life in New Zealand.

Excavating sea mammal and moa remains at Watsons Beach, South Otago, in December 2001. Picture: Chris Jacomb

Two years ago Ken Tustin was walking along Watsons Beach on the South Otago coast to the family crib at Bull Creek when he noticed shell midden eroding out of the sand dunes. On closer inspection, he and his wife Marg found several Maori artifacts lying on the surface, including quartzite butchering knives and stone fishing-lure shanks, as well as the bones of moa and sea mammals. Recognising the significance of the find, they contacted local Ngai Tahu kaumatua Martin Palmer and since then the site has been a centre of attention in South Otago.

Butchering knives made from silcrete which were found at Watsons Beach. Picture: Chris Jacomb

Watsons Beach is located in a sandy bay about forty kilometres south of Dunedin. The archaeological site was first recorded as a small exposure of mussel midden by Jane Teal in 1977 during an Historic Places Trust survey. Since then a considerably larger area has been exposed than was first recorded. By 2000 the site was visible as patches of midden material intermittently exposed over 300 metres of low, eroding sand dunes.

An umu (earth oven) at Watsons Beach. The erosion of at least a metre of sand from the site at this point has left only the base of this umu exposed. Picture: Chris Jacomb

The local Ngai Tahu representatives, Moturata Taieri Whanau, were concerned at the rapid deterioration of the site and contacted Otago University and the Historic Places Trust for assistance. The University's Anthropology Department made a detailed record of the site and monitored its condition over several months. Then in December 2001 the Trust undertook a salvage excavation to rescue archaeological information before it was washed away. A large excavation team worked on the site for a week. The team included Trust staff, Ngai Tahu, archaeological consultants, and students from Otago University.

Excavation in progress at Watsons Beach, December 2001. Picture: Chris Jacomb

The excavation showed that the site was probably limited to a single dune ridge and was shallow and discontinuous, indicating relatively brief occupation. The main activities at the site revolved around fishing, shellfish gathering, and fowling, as well as moa and sea mammal butchering and consumption. There was also evidence for stone tool making, as well as possibly some ceremonial activity involving red ochre. One of the most interesting results from the excavation was the discovery of several concentrations of small bird bones and many parrot beaks. The birds were generally too small to have provided much meat and were more likely to have been hunted for their colourful feathers.

Sites with evidence of moa hunting are relatively rare on the South Otago coast. Between the Otago Peninsula and the Clutha River mouth sparse moa remains have been reported from only a few sites. Although not much moa bone was recovered from Watsons Beach, tracheal rings sugge st that at least one moa was killed nearby, since the head, neck and feet were normally left at the kill site. A relatively large amount of moa eggshell was found.

Stone for tool manufacture appears to have been obtained from various sources. Adzes were made of argillite that may have come from both Southland and Nelson quarries. Stone knife blades were made from silcrete and porcellanite that probably came from Central Otago. The many small tools and flakes of obsidian found indicate contact with the North Island since the nearest source of that stone is near Lake Taupo.

The Watsons Beach site is one of only a small number of open coastal sites to have been systematically investigated in southern New Zealand. The artifacts and food remains found indicate that the site was occupied during the earliest phase of Maori settlement, probably about 600-700 years ago. Detailed analysis of the material recovered will yield important information about early Maori settlement and interaction with the environment on the South Otago coast.

The site is one of an alarming number of Maori archaeological sites to have been damaged recently by what appears to be an increased rate of coastal erosion in southern New Zealand. The cause is not yet known. It may be related to unusually heavy seas from both southerly and easterly weather patterns. Rising sea levels could also be a factor. Other southern sites known to have been affected include Masons Bay and others on Stewart Island; Papatowai and Jacks Bay in the Catlins; Sandfly Bay and Purakanui on the Otago Peninsula; and Kaitorete Spit and Tumbledown Bay in Canterbury. The University of Otago has carried out two excavations at Purakanui as a result of coastal erosion damage and the Trust has been involved in salvage excavations of a site on Kaitorete Spit exposed by wave action. It is not only natural processes that cause erosion. Hundreds of sites are damaged or destroyed every year by people with four-wheel-drive vehicles and horses, as well as by grazing stock and sand extraction.

This is not unique to New Zealand. Coastal erosion is one of the most serious threats to archaeological sites throughout the world. Along England's east coast unrecorded sites are being uncovered by erosion, while well known sites are disappearing into the sea. In Scotland a pilot project called "Shore Watch" monitors the condition of exposed coastal sites. International research has shown that identifying areas subject to erosion is a priority if we want to save archaeological sites in high-risk coastal areas.

In New Zealand further study is needed to determine the extent of the threat from coastal erosion, to prioritise remedial action on particular sites and to establish how best to manage the land on which these sites are located. Historic Places Trust staff are seeking to involve key stakeholders in such studies to ensure that strategies are put in place to manage coastal sites before they are lost forever.

Chris Jacomb is the Historic Places Trust's Archaeologist, Southern Region and Rachel Darmondy its Archaeologist, Lower Northern Region.