Our changing climate and rising sea level is having an impact on our archaeological heritage. New Zealand Archaeology Week provides an opportunity to raise awareness of these changes.

In March 2020, prior to New Zealand’s Covid-19 lockdown, Auckland Museum archaeologists carried out a small excavation in a large coastal midden on Otata Island in the Hauraki Gulf, Tikapa Moana, in partnership with landowners and Ngāi Tai ki Tāmaki. The aim of the excavation was to record information from the important site before it is lost to erosion.

The results of this project will also provide a baseline for understanding the changing marine environment around Otata and a valuable comparison for modern surveys being carried out.

In January 2018, huge swells in the Hauraki Gulf caused widespread damage to coastal areas. In only a few hours the previously stable, vegetated coastline of Otata had been reduced by up to five metres, exposing the 50 meter length of midden. The waves removed shingle from the beach, which previously offered protection to the midden, which put it at increased risk of damage from further storms.

The Otata midden highlights the vulnerability of heritage sites as more intense weather events, coastal erosion and sea level rise is expected in the future. There are more than 2000 recorded archaeological sites in the inner Hauraki Gulf, including defensive pa sites, kumara pits and midden, with many of these in low lying at-risk areas. These sites are important to help understand early Māori use of the Gulf.

As it is not practical or feasible to build sea walls to protect them, archaeological excavation is the only way to preserve this important information.  

The Otata project is enriched through its partnership with Ngāi Tai ki Tāmaki, incorporating Te Ao Māori into the results by looking at traditional knowledge and oral history alongside the archaeological record. Climate change, sea level rise and increased storm surge is already having a detrimental impact on coastal archaeological sites. Unfortunately, with many likely to be destroyed or severely damaged in the coming years, a huge amount of information about the past will be lost. This project hopes to demonstrate how archaeological investigation, coupled with mātauranga Māori, can be used to support anecdotal and contemporary climate data in the development of climate change responses, resource management plans and conservation. For further developments, watch this space.


Image caption: Auckland Museum archaeologists, Auckland Museum staff, Ngāi Tai ki Tāmaki​ representatives and members of the Neureuter Family on Otata Island


Blog: Excavating Otata Island: A Midden Revealed by Auckland Museum Assistant Curator, Archaeology Emma Ash. Published 30 April 2020