"Natural fish/cultivated fish" and national records.

[JerryC]

It’s certainly an interesting topic that I have enjoyed spending many a happy hour researching, also the commercial side. None of us will know for sure but there is recorded evidence that we used to import carp from France and the Netherlands prior to the 14th century for banquets etc., to me that indicates something
It’s interesting that Izaak Walton (although I prefer to base my research on sounder information) wrote in his “Complete Angler” in 1653 that the carp had been in England “about a hundred or a few more years,” quoting the “Chronicle of Sir Richard Baker”“Hope and Turkeys, carps and beer, Came into England all in a year.”
This annus mirabilis was round about 1530, and at about that time the monasteries were suppressed by Henry VIII. I prefer to go with the mid 14th century as to the introduction as the ‘carps’ mentioned by Izaak may well have been here prior to the reformation but with the dissolution of the monasteries many of these carp would have been taken from the monastery ponds and released elsewhere giving the impression to folk that they had just appeared.

[Gary Bills]

I would agree, Jerry, that the weight of evidence, on the whole, points to the medieval period for the introduction of carp to the UK, with the Roman period as an outside chance. Perhaps the "mummified" carp arrived here dessicated, - smoked..who can say? Perhaps it had been swimming in a pond outside the villa?
If I recall correctly, the gist of the Classic Angling article was that a certain mountain lake in Wales, close to the site of a Roman fort, was found to contain feral commons - ergo, they had been put in there by the Romans.
Well, maybe.... :think:

[Gary Bills]

Walker - I think in the CCC letters, points out that Mother Nature - left to her own devices - will produce few giants. Now I recall, he was writing about the ferals of Hunstrete, unless my memory is poor...
Well, in any case, he made the observation that, by the process of natural selection through time, the average size of carp in any pool will be determined by the available food sources, and that the tendency - over time, is for stocked carp to breed smaller offspring, and their offspring will breed smaller descendants etc, for this very reason. I'm no scientist, however, and perhaps Snape is our man to elaborate on this point?

[Santiago]

My understanding of the matter is carp are 'no different' to goldfish in a fish tank! Put one in and it will grow to a maximum size that is limited by food and oxygen levels, but put 2 in and the fish will be smaller when they reach their maximum size, put 3 in and the fish will end up even smaller.

In a more natural environment, like Redmire, so long as there is plenty of food and oxygen for every carp in there, their growth will not be limited by these factors but by their genetic strain. Overstock a lake, then you have to 'feed' the fish and manage the water quality, if you want the fish to grow bigger than they would otherwise do at that high stock level!!

In a reasonably well stocked lake that was left alone, ie., an unfished neglected estate lake, the carp would breed to a fixed mass sustainable for that lake. There would be over time a predisposition for the average weight per carp to be lower, to a point in time when recruitment would be limited by cannabolism by mature carp. At that point or thereabouts, the tendency for the individuals weight to decrease would stop, and recruitment would be very limited. For a number of years the hypothetical lake would then contain mainly mature fish, but as the population ages and the older fish die or are predated, recruitment will then increase, but the average weight of the mature carp would remain the same or increase a tad. Bar seasonal variations, a balance would be struck between the carps average weight, food supply, oxygen levels, and recruitment. Change any of these factors and balance will change, i.e, introduce a top predator like an otter, that can take mature fish, and the number of carp will decrease but the average weight will increase.

I am a scientist, a biologist, but have not studied fish ecology for many years, but the above is a basic summary of what I remember.

[JerryC]

And of course temperature is also important , with best growth being obtained at a water temperature of 23-30°C.

[Santiago]

Yes, forgot to mention temperature. Also, for best growth rates you want a large shallow lake where sunlight can easily reach and support plant life on more than 90% of the bottom. Mineral water content is also important; not too much to encourage algal blooms and consequential oxygen depletion, but enought to support plant and animal growth!!

[Ron Clay]

As far as I am concerned, the Romans introduced carp to the UK.

They were breeding them in parts of Europe and I don't see any reason why they should not have brought some here.

[Davyr]

As far as I am concerned, the Romans introduced carp to the UK.

They were breeding them in parts of Europe and I don't see any reason why they should not have brought some here.

As there's no conclusive evidence one way or the other, "Yer pays yer money and yer takes yer choice":

"The Carp family were originally introduced to the UK by the Romans, the majority of which were probably caught in the Danube before being transported across Europe."

http://www.maggotdrowning.com/fish/carp.htm

"They probably weren’t imported by the Romans either, because there is virtually no evidence for the import of carp to continental Northern Europe prior to the 12th century. The Romans knew all about carp, but it appears that they weren’t bothered about bringing them to Britain. After all, there were plenty of other freshwater fish, not to mention the sea. Why should they go to the trouble?"

http://www.fishingmuseum.org.uk/carp_in_britain.html