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.