Regular visitors to Jessica’s Nature Blog will no doubt have noticed the frequency with which photographs and articles are posted about the many variations to be seen in the shells of the British Native, Flat, or European Oyster, Ostrea edulis Linnaeus. Variation in oyster shells has been a subject that has interested me for many years - mainly because of its implication for the understanding of this particular marine mollusc in archaeological contexts. You can see these previous oyster shell posts by clicking here for the Oyster Variations category.
The following is the first instalment of an 8 part summary of the work I have been undertaking on Flat Oyster shell specimens from archaeological and present day contexts under the title Two thousand years of eating oysters in the UK: an archaeological perspective. The contents of these parts will be as follows:
Part 1 - Introduction and Background to the research
Part 2 – Methods
Part 3 – Caveats to analyses of the archaeological data
Part 4 – A few results: Size differences
Part 5 – A few results: Infestation differences
Part 6 – Exploitation models: the evidence considered as a whole
Part 7 – The general picture: Roman, Medieval, and Modern
Part 8 – Future work and References
Two thousand years of eating oysters in the UK:
an archaeological perspective
Easily observable features in oyster shells from archaeological excavations can provide important evidence of where the oysters came from and the way they were exploited by man.
The shells of the European flat oyster (Ostrea edulis L.) are immensely variable and reflect the natural environment in which the mollusc was living as well as the human activities associated with their collection, their use as food, and the method of their disposal. There have been extensive studies of large oyster middens from early periods worldwide, such as those at Ertebölle in Denmark, Mesolithic sites in Scotland, and later with the colonial period in the Americas. However, relatively little work has been undertaken on the more recent archaeological oyster deposits of the last two thousand years in the United Kingdom where mostly the quantities of shell are smaller and the sites can be inland as well as coastal, and both urban and rural.
This article gives a very brief overview of the methods and preliminary results of investigations that have been made into oysters from excavations of these relatively recent archaeological sites in Britain – using observations of their macroscopic characteristics. It is based on a series of published and unpublished reports made to archaeological organisations, and also the doctoral thesis: A study of the variation in oyster shells from archaeological sites and a discussion of oyster exploitation (Winder 1993).
BACKGROUND TO THE RESEARCH
Awareness of this potential research opportunity was raised in the 1970’s when a surge of construction development and its associated archaeological investigation uncovered large quantities of marine mollusc shells. An example of this was the excavation of Saxon Hamwic in Southampton where vast numbers of marine shells were recovered, mainly oyster, from domestic rubbish pits. The archaeologists had hundreds of large museum boxes full of mud-caked shells in store and wanted to know what to do with them.
Had these shells, they wanted to know, any potential for site interpretation? If so, could they be used to indicate how important marine molluscs were in the diet of the community? Where did the shellfish come from? Was it possible to establish the locations being fished in order to understand how far afield people were going for food and to suggest trade links and routes? How intensively were the shellfish beds being exploited – how much effort and organisation was invested in the activity?
Another aspect which intrigued archaeologists was whether some degree of oyster cultivation had been taking place. Were the oysters fished from natural (wild) beds or were they farmed, cultivated and subjected to more commercially orientated activities? It had always been assumed by historians that the Romans introduced oyster cultivation to Britain but could this be substantiated from the archaeological record?
The problem for the archaeo-malacologist is to discover what actually survives in the oyster shells that can possibly help to answer the questions posed by the archaeologists about the way people have exploited oysters in the past. Much of what is already known about the oyster and man relationship can be found in the general literature, particularly accounts from the 19th and early 20th century discussing eating, fishing and farming oysters. Despite some serious gaps in the periods covered, and not a few misunderstandings, this older literature contains some very useful information – including a quotation from the Roman poet Lucilius who said:
“When I but see the oyster’s shell,
I look and recognise the river, marsh or mud,
Where it was raised.”
It is clear from allusions in the literature that, in fresh oyster shells at least, it is possible to observe variations that could be attributed to the place of origin. This idea was developed by Alfred Bell in the Essex Naturalist of 1921 where he meticulously described variations of British oyster shell shape, ascribing sub-species and variety names to specimens from different locations. Unfortunately, it seems likely that his descriptions may have been based on just a single specimen in some cases.
So, the task in hand was first to decide which particular surviving characters in the oyster shells might be useful in answering the questions posed by the archaeologists; and second, how to analyse the recorded information in a meaningful scientific way. This will be discussed next, in Part 2 of this account, which will briefly describe the basic methods used in the research.
N.B. Please leave a comment or e-mail me directly on firstname.lastname@example.org if you would like to ask any questions or to have a free copy of the complete article sent to you as a pdf file. This article is just a very brief summary of my archaeological oyster research. A small selection of references to publications and reports will be provided with the article.
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