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History of the AOTEA SCIENTIFIC RESERVE The Sandhills By Owen Wilkes (1)
Owen Wilkes 13 Sept 2001
The block of land known as Oioroa at Aotea North Head was gazetted a scientific reserve in 1978, with the intention of preserving the the numerous archaeological sites which had been partially investigated by Auckland university archaeologists, and the spectacular sandhills.
This paper summarises the archaeological work which has been done so far in and around the Reserve and tries to evaluate the archaeological values still present in the Reserve which warrant future preservation.
ARCHAEOLOGICAL WORK DONE
Most of the work done in and around Aotea Scientific reserve (ASR) was done by anthropology students in the early seventies under the overall direction of Richard Cassels who was then a lecturer in the Anthropology Department of Auckland University. The work done can be summarised under three headings: site recording, excavation, and midden analysis.
Site recording
Cassels and his co-workers carried out field recording of all detectable archaeological sites around the northern shores of Aotea harbour and up the coastline from Aotea North head to Ruapuke beach.
The recording was not of very high quality - generally only sketch maps were drawn of pah sites etc, but the site records are still valuable because many of the sites recorded then have disappeared entirely since, through natural erosion, farming activities etc.
About 50 sites were recorded. Manuaitu pah was accurately mapped using a plane table and autoreduction alidade.
A particularly significant aspect of the field archaeology of the Aotea peninsula (north of ASR) is the widespread evidence of former horticultural activity, in the form of modified kumara soils, borrow pits (which supplied coarse sand for mulching kumara), ditch-and-bank fences, and garden terracing.
One of Cassels students wrote a paper about the modified soils. He was able to show that there are about 100 ha of old kumara gardens on the peninsula. These were supplied with sand from 380 borrow pits, each averaging 260 cu m, giving an astounding total of 102 000 cu m excavated and spread onto gardens - in pre-wheelbarrow times!
Excavation Cassels and co-workers carried out excavations on several small sites on land just outside the northwest corner of ASR. The sites each consisted one or two house terraces with associated kumara storage pits and shell middens.
The results were published by Aileen Fox and Cassels as "Excavations at Aotea, Waikato, 1972-75" in the Records of the Auckland Institute & Museum.
Cassels had earlier investigated prehistoric settlement patterns in the inland Waikato, and the work at Aotea was intended to discover any differences there might be between the patterns of inland and coastal settlement.
It appeared that at each of the Aotea sites was occupied more or less permanently by a quite small group of people, probably a single family, who were engaged in a variety of activities including gardening, fishing, shellfish gathering, woodworking and stone tool making. The people were living there from about 1450 to 1550 AD.
The results of the excavation are quite valuable because so little archaeological excavation has been done on the Waikato-King Country coastline, and because it was done in conjunction with the midden analysis described next.
Overall the work gives us quite a good picture of everyday life of ordinary people in peaceful times - the sort of information which tends to be lacking from traditional history which is more concerned with important people and warfare.
The sites excavated by Cassels have since been destroyed by farm cultivation.
Midden analysis
Cassels and his students sampled about 150 of the shell midden heaps that were then exposed in ASR. About a bucketful was taken from each midden, and it was sorted out into shellfish species and weighed. All this involved an enormous amount of unpaid involuntary student labour.
At the same time the biomass of living shellfish in the harbour was also studied, and the "standing crop" calculated. Experimental harvesting of shellfish was carried out in the harbour.
Cassels never published his results, but he did give a conference paper about them in Christchurch in 1973.
His data is filed in the NZ Archaeological Association site records and I have recently been reanalyzing some of it.
Overall the percentages of different shellfish were
cockle = 53%.... pipi = 37% .... tuatua = 7%.... mussel = 3%
Cassels was able to show that tuatua were the "most preferred" shellfish, but they were also the species in shortest supply. Pipi was the mainstay, and cockle was avoided when possible, but eaten when others were not available,and therfore ended up being the most eaten.
Times to collect a meal for a family were calculated for the various species:
cockle 1.5 hours
pipi 1
tuatua 4
mussel 0.5
The food value was calculated:
cockle = 106 cal/kg.... pipi = 133... tuatua = 133... mussel = 153
This shows why mussel was so popular - there was more meat on it relative to the weight of shell, and it was far more easily harvested.
Tuatua was
presumably preferred for its taste. For cockle and tuatua the energy consumed in gathering and transporting was probably comparable to the energy obtained from the food (Cassels calculated that a 60 kg woman carrying a 25 kg load of shellfish burned up 3.6 cal/minute on the flat, 9.5 cal/min on a sandhill, etc etc. All very scientific but perhaps not very realistic!)
Standing crop was the crunch.
Assuming there were 300 people living around the harbour and that 65% of their calories came from shellfish, then the standing crop was:
cockle 399 days per year
pipi 93
tuatua 1
mussel 30
In other words there was more cockle in the harbour than anyone wanted to eat. Pipis could provide all the calories the hypothetical human population needed for about one quarter of the year.
Tuatua were in very short supply and no doubt some sort of rahui was in force.
By looking at the distribution of shellfish species in the various middens Cassels was able to show that people were mostly eating the shellfish that were nearest - which probably means that they journeyed to and camped at the various places so as to harvest the shellfish there rather than carry the shellfish to their permanent homes.
Distance to resources was important in those days, when everything had to be carried on a human back.
Within any particular shell heap or layer there was generally more pipi at the bottom and more cockle at the top. This would seem to indicate that in any particular shellfish "season" people cleaned out the local pipi first, and then started on the cockle.
All these results could have important bearing on the re-establishment of shellfish stock in the harbour today and for their future management. It is a pity that Cassels did not do more of this kind of work.
THE SITUATION TODAY
Probably two thirds of the midden heaps sampled by Cassels have now disappeared - mostly they have blown away, although a few of them are reburied. A few sites have emerged from the sand that were not visible when Cassels was active.
On the other hand ASR is now far more unique archaeologically today than it was then, because other similar assemblages of sandhill middens along the Waikato west coast are now largely destroyed while, relatively speaking, ASR is well preserved.
In particular there has been massive destruction of sandhill sites by ironsand dredging at Taharoa and pinetree logging at Kawhia. Sandhill sites at Nukuhakari and on Raglan north head have probably suffered worse wind erosion than those in ASR. Sites on the Smith and Morrison properties are now hidden by marram grass.
URGENT WORK THAT NEEDS TO BE DONE
The most urgent issue at ASR exactly how fast the sand is being destroyed, that needs to be worked on is establishing moving and how fast archaeological sites are being destroyed.
Some idea of sandhill air photos, and there happening now we need movement in the past can be got from looking at old are air photos going back to 1943. But to tell what is good datum points from which to carry out measurements at, say, one-year intervals, ground near the foot of each important sites. I suggest that waratahs be driven into the approaching dune in the vicinity of the more important sites.
The best way of determining how fast the middens are being destroyed is by re-photographing them at regular intervals.
Many of them were photographed by Cassels in the early 70s and by Lands & Survey ranger John Greenwood in the late 70s, but I have so far been unable to re-locate more than 2-3 of these photos, and they are undated.
I started taking photos in 1997, and already it can be seen by looking at these photos that the middens are being blown away much faster than I at least previously thought.
As a first step to trying to control erosion of sites I suggest that a geology student be encouraged to write a thesis on the geomorphology of the dunes - the mechanisms/that form them and move them, and the possible mechanisms for controlling their movement.
POSSIBLE FUTURE ARCHAEOLOGICAL WORK
Cassels made an important and worthwhile start to investigate a quite important topic - the inter-relationships between a prehistoric group of people and their local
environment. It could be very helpful for future environmental management and protection if his work was carried further.
The biggest weakness in the Cassels work is that he had no chronological control. No-one knows how old the midden heaps are or whether they were accumulating
simultaneously or consecutively. The most important need is for good carbon dating of as many of the Cassels middens as can be re-identified.
The midden analysis techniques used by Cassels were relatively crude. Using modern techniques a lot more information could be got from much smaller samples. For example fine-mesh sieving can yield tiny fish otoliths which can be identified, so that a picture of fishing activities can be built up even if there is no ordinary fishbone present (because it was usually eaten by kuri).
Microscopic examination of the shellfish themselves can indicate at what time of the year it was harvested, oxygen isotope analysis can indicate the temperature of the water in which the shellfish grew. Measuring the size of the shellfish could give an idea of the harvesting pressure being put on the harbour environment. All this could be done with very little further damage to the middens.....more on Aotea Scientific Reserve
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