Hi Shellfishguy (do you have another name?) - have you had a look into SHARP's oystershells? There seems to be quite a lot of those. Why have you focused on mussels?

Hello Eve! My interest in Sedgeford started with a sample of the oysters in ditch fill 302 of old Trench 3. My report on this should be in the site archive. The focus on the mussels was imposed on me by the evidence, a gully packed with mussels in last year's trench. I hope to get back to the oysters when we re-open the area around old Trench 3, probably year after next.

Phil: Oysters are quite big and tough, but can't last for long in fresh water. Sea-water is about 30-35 parts per thousand (ppt) salt, so that's the outside concentration oysters are designed for. They expect some sea-water to leak in across their skin and gills because they are saltier inside than outside. Water solutions tend to try to mix until concentrations are equal; if they are separated by a membrane that is weakly permeable to water, this produces a pressure difference between the two sides of the membrane, called the osmotic pressure. The greater the concentration difference beteen the two sides of the membane, the greater the osmotic pressure, and the faster the water leaks across the membrane into the saltier side. Oysters can pump the water back fast enough to compensate if the water outside them is brackish (down to about 18ppt), but if the water outside the oyster is less salty than that, effectively their biological bilge pumps fail, and they slowly swell up until they die. So holding tanks could only work if they can be filled with at least brackish water.

It's also very useful for the holding or fattening tanks to get flushed at least once in a while by fresh sea-water (washing out fouled water and replacing it with fresh water full of plankton, oyster food). So holding tanks could only be sited no further inland than the tops of estuaries.

And I am

Greg Campbell

Hello Phil. If the water at March is salty enough due to sea-water to be worth boiling for salt, it would probably be alright for refreshing oysters. But I doubt that the salt-panners would want oysters in their tanks, since oysters do excrete, and do have some bacteria which you wouldn't really want in your salt. Salt is hugely expensive in fuel terms to boil down, so the head salt-merchant wouldn't like off stuff in his goods.

Also, the salt content gets way over the 45-50ppt that oysters can stand (the osmotic pressure means water is pulled out of the oyster through its skin and gills faster than it can pump it in), so the oyster merchant might end up putting his oysters into water that was either too fresh or too salty. If the water in the river is brackish, it would be more likely that they just hung the nets or baskets (or whatever they used) full of oysters straight in the river. If there were specialist oyster tanks, they would have hardly any oysters in them (the idea was to sell them to Durobivae, not leave them in tanks).

I also bet there was no need for tanks ove that distance: I bet it would have taken far less than three days for professionals to get freight from King's Lynn to Peterborough by water. I make it about 35 miles and nearly level. Canal boats (originally pulled by horses) expect to do about 4 miles an hour, so that distance would take about a full day. Fly-boats, smallish canal boats specialising in perishable cargoes, like cheese, which changed tired for fresh horses regularly and moved all day and all night, could get from Ellesmere Port to Birmingham (65 miles, including locks) in a day. In 18th century Canada, furs destined for Europe were brought from deep in the wilderness by river in big canoes by teams called voyageurs. A team of 7-10 voyageurs would expect to take about 3 tons of freight about 50 miles a day.

'Peterborough to Lynn, ma'am? Step aboard, I'll get ye home fur yur supper...'

I am concerned about the term 'farmed'. They may have been harvested within 24 hours, but telling whether they were farmed, dredged directly from natural beds, dredged from fattening beds, or hand-collected is far more tricky. I would like to see what the oysters at Sawtry looked like before making any comments.

It's much in favour at the moment in archaeology to create a hypothesis, think up ways to test it, and examine the evidence. That sounds all well and good, but can lead us to believe that we have found the explanation for a pattern in the archaeological record, when that pattern was in fact caused by some behaviour which we have not explained. In fact there may be multiple explanations for the same pattern that are different for different periods. I'm not too sure that patterns in the remains that we think are caused by differences in gender or status aren't just projections of our own concerns and perspectives onto the past. I prefer looking at heaps of data for the patterns, and creating explanations for those patterns.

So I would not be looking at Sawtry oysters knowing in my head what farmed, fattened or natural-bed oysters look like so I can announce what they are to you: I would be looking at Sawtry oysters to see whether they can guide me into telling apart farmed, fattened or natural-bed oysters. Modern oysters are almos fished out, so the only records for the nature and extent of natural oyster reefs are in archaeological sites.

Hi Phil, this is off the topic of oysters, but since you brought it up, what is constructivism? I don't know anything about the different theories of archaeology and don't know what these different terms mean. (I am very envious of you and others in Britain living surrounded by archaeology and excavations. I would love to do a degree in archaeology - but here is would mean going to school as a full=time student, and I think it would focus on Canadian archaeology, understandably, but it isn't something an amateur can easily get involved with as a volunteer.)

hi Eve, I am lucky enought to have found a flexible university. Anglia Ruskin. I am able to fit in my degree around work and family life (wife and three children). Only issue is that part time means it will take six years. good thing is by the end on six years I will have a fair amount of field experience. I now have excavating experience other than SHARP albeit only a couple of test pits and loads of surveying and desk based assessments with my course.

Constructivism recognises that we each have thoughts, notions and feelings which 'get in the way' of an unbiased theory of what it is we are excavating. These thoughts etc. may be as a result of our ethnicity, our gender, race or religion just for starters. The films we watched as kids or the books we read, our parents opinions and a whole host of other influences affect our perception of the past. Extreme constructivists will argue that it is impossible to interpret archaeological raw data scientifically because of these influences.

A brilliant example. The theorist would find names for the two different stances taken. Possibly feminist for the women and androcentric for the blokes. Could it have been a harvesting accident??? What is wrong with a woman involved in a swordfight? or a man killed by his jealous wife?
What a fabulous subject archaeology is.

Naturally self-sustaining beds of oysters (where there are enough grown-up oysters making baby oysters to replace at least all the oysters harvested) were common all along European Atlantic coasts until the 1930s or 1940s. They didn't occur everywhere, but you wouldn't have to go far to fish for some. Reefs (oysters which attached naturally to each other forming large structures) are harder to trace, but probably survived in large numbers until the last quarter of the 19th Century.
Now, native oysters are now close to finished, due to unsutainable fishing combined with diseases (many of which were spread by oystermen transferring oysters beteen beds for fattening). There are now about two dozen self-sustaining beds. Seven small bays in Ireland, three or four West Scottish sea lochs, one in Belguim, three or four in north Brittany, and in the estuaries of the Thames, Exe and Fal and in Southampton Water/Solent in England. Accidental or intentional introductions have led to beds in the Danish Lymfjord, Lough Ine in Ulster (the Solent beds may be the result of accidental introduction in the 1960s). Almost all of these are almost dredged out.

Oyster reefs are extinct everywhere in Europe (inlcuding the Med and the Black Sea). If anybody finds one they would be given statutory protection.

Most Atlantic native oysters are farmed, mostly by the French (in Arcachon Bay) and the Spanish (in Cantabria). Most oysters are now native oysters, but Crassostrea gigas, a species introduced from Japan. Escapes are now taking over beds that might have been colonized by natives, and building reefs along the Dutch coasts.

Regarding the fatal injuries post I consider that it would be almost impossible to tell the difference. I cannot think of a Saxon example but the Romans were supposed to be very good at amputations and apparently it was a fairly common operation. There are various illustrations of Romans walking with crutches who we assume have had their legs amputated but how many skeletons have been found to confirm this - none. Thus I suspect it is fairly difficult to tell from the skeleton what actually happened.

Hacked skellies - I can't now remember which skeleton it was, but I think it was one with several cuts around the head. I also recall that there is one that was or may have been garrotted, which would be unlikely to have been an accident.
I wonder how many scything accidents would occur to the head vs. the legs.
Re the oysters - I hadn't realised there were so few self-sustaining beds are left - makes me feel guilty about eating oysters. World-wide, are they now given much protection? Are there oyster beds in N.America?

How sad . . . How unkind we are to the planet.