Coastal Adaptations – Did They Emerge in the Late Holocene?

Australia: The Land Where Time Began

Coastal Adaptations – Did They Emerge in the Late Holocene?

At Princess Charlotte Bay, on the eastern side of Cape York Peninsula, the bay had formed around a sandstone plateau, that was crescent-shaped, and looked out over silt and mud flats, with islands clustered at the eastern end, excavation was carried out by John Beaton in 1970. Walaemini Shelter is the site with the earliest evidence of occupation at this location, radiocarbon dating estimating an age of 5,480 (5,450-5,595) BP for a marine shell midden. Endean Rockshelter on Stanley Island contained evidence of human use of the islands which indicated that cultural activities occurred which dated to 2,350 (2,330-2,495) BP, though no earlier. Evidence for the consumption of molluscs was found in those as well as other rockshelters in the mid- and Late Holocene (Beaton, 1985), which was supplemented by kangaroo and turtle meat. It was observed that in shell middens on the mudflats there was a similar economic focus. Only one of the middens, the South Mound that was 2.4 m deep, that was dated by a large series of radiocarbon analyses, was reported on by Beaton, that were estimated to be between 1,700 and 1,000 years old. The earliest level of the shell mound was found to date to later than 2,000 BP, though the mudflats began building up at about 4,000 BP.

A surprising chronology of human occupation in the region was displayed (Beaton, 1985). There were 2 occasions he believed foragers did not use landscapes that were newly formed (Beaton, 1985). The first of these was about 7,000 BP when the sea rose to levels that were almost at the present day level, a time when the ocean was brought to the foot of the plateau; yet 1,500 years later humans arrived in the area based on the earliest known archaeological evidence. It had been reasoned by Beaton that foragers would have been displaced by rising sea levels and appeared in Princess Charlotte Bay if they had been on the coast 7,000 BP, but he could not find any evidence of their presence he concluded that foragers had not focused on marine resources in the Pleistocene and Early Holocene. Beaton also recognised that was a second failure to immediately exploit marine resources, saying that people did not use marine resources when they arrived in the area 5,500 BP, instead gradually making use of marine resources over an extended period of time. The evidence for his conclusions was the absence of archaeological evidence of the use of islands before 2,350 BP and the absence of shell mounds that would indicate intensive exploitation of mollusc beds until even later.

It was suggested by Beaton that these delays in the settlement of the area around Princess Charlotte Bay resulted from reduced marine productivity and low diversity of species in the near coastal waters that was caused by rapid sea level rise. According to Beaton marine ecosystems were unstable and foods were scarce after the sea level rose – which made for extremely difficult conditions for foragers. It was speculated by Beaton that the rise of the sea level was so disruptive that large populations of humans could only rarely be sustained on the coast until much later, once the marine environments had stabilised. Beaton hypothesised that there was a significant ‘lag time’ between the arrival of the sea at its current position, and the development of marine resources to such a level that they could sustain large populations of humans. He suggested that a consequence of late emergence of rich marine landscapes was that population increased substantially late in Australian pre-history.

Beaton (1985) argued in a review of other coastal areas that the coastal lag time he had inferred for Princess Charlotte Bay also occurred elsewhere. He concluded that early middens were only 5,000-6,000 years old, and were formed long after the sea had risen to its present level. Beaton believed that this was evidence that coastal concentrated occupation was often prevented until long after the disruption caused by the rising sea level, only occurring after the marine ecosystems had stabilised. The idea that the coastal economies had been the earliest and most fundamental strategies of foragers during the Pleistocene was denied by this ‘coastal lag’ model, and he hypothesised instead that in all locations specialised use of the coasts was a late a late phenomenon, emerging after a long period during which marine resources were not exploited intensively.

The coastal lag model of Beaton reproduced in several ways elements of the ‘progression’ model of life in the Pleistocene. This was a process that occurred uniformly across Australia, and is an image of coastal exploitation becoming more sophisticated and intense over time. Following the rise of the sea level ecological disruption occurred in a number of regions, and there is evidence that in some localities intense coastal exploitation of the kind seen historically developed only in the Late Holocene. During and following changes in the levels of the ocean reorganisation is inevitable, as a consequence of altered levels of the ocean the reality of major changes in the coastal ecology during the mid- and Late Holocene, does not mean that the image of coastal life suggested by Beaton is correct.

It is not easy to assess coastal occupation at Princess Charlotte Bay during the Pleistocene and Early Holocene. Beaton believed that it was indicated by the lack of debris of occupation between 7,000-5,500 BP that humans were not present, but Hiscock suggests this may not be a sound conclusion. Evidence has been found at Walaemini Shelter that people were present in the area 5,500 years ago, that is the only evidence of human activity that has been found that dated to that period, not even at Alkaline Hill Shelter that is few kilometres away has produced any evidence. Also, at Walaemini Shelter a dense marine shell midden was found in the oldest cultural deposit which revealed that foragers in Princess Charlotte Bay had collected marine molluscs and caught birds. Open-air middens would have existed at that time, though none have been preserved, as part of the same system of use of coastal resources. Not much evidence has been preserved that would indicate humans were using the landscape between 5,500-4,000 BP, and Hiscock suggests that the absence of earlier archaeological sites may simply be an indication of the extent of the destruction of material that has occurred in that region. It is not surprising that early middens at Princess Charlotte Bay were destroyed; traces of coastal middens can be obliterated rapidly by cyclones (M.K. Bird, 1992), and special conditions, such as chenier ridge buildup during storm surges and cyclones (O’Connor & Sullivan, 1994), help preserved middens dating to the mid- and Late Holocene. Better preservation in recent millennia may be a reflection of the image of more sites and coastal occupation that was more intense in the Late Holocene, rather than a change of the use of resources.

Whichever is the case, the history of resource use at Princess Charlotte Bay is not an indication of early coastal economies elsewhere. Archaeological sites dating to the Pleistocene have now been found at places close to the ancient coastline, in places where people could possibly have exploited coastal resources (Neal & Stock, 1986). The remains of marine animals have been preserved at a few of these places, such as Mandu Mandu Creek Shelter and Koolan Island Shelter, which makes it clear that during the Pleistocene some people were capturing and consuming sea foods (Morse, 1988; O’Connor, 1989a, 1999b; Bowdler, 1990, 1999). Also, evidence has been found of people exploiting marine foods during the Early Holocene in rock shelters in Tasmania, the West Kimberley region (O’Connor, 1994) and the Whitsunday Islands (Barker, 2004), which demonstrates that coastal foraging was occurring much earlier than the mid- to Late Holocene.

It was argued by Beaton that environmental disruptions associated with the rising sea level prevented the intensive exploitation of marine resources by humans until the mid- to Late Holocene, when stability was achieved in marine ecosystems which enabled focused exploitation of marine resources. Hiscock suggests this is not likely to have been true for all coastal areas as they had very different environmental and social histories during the Holocene. It has been demonstrated by archaeological investigations that the settlers persisted in coastal landscapes in times of dramatic environmental change by making adjustments to their economic activities. Humans living in coastal areas had a long history of adapting to environmental changes that were caused by rising sea level. Oceans had been rising since the close of the LGM, not only at the start of the Holocene. During the mid- to Late Holocene rising sea levels simply continued an already existing process of transforming the coastline instead of creating new problems for foragers. The tropical coastline in the region of the Whitsunday Islands, to the south of Princess Charlotte Bay, is an outstanding example of an economic change in coastal foraging over an extended period of time.

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