Carp are said to spawn at water temps between 18 and 24'c. Midland rivers' water temp often rises over 20'c (Severn up to 23'c this year) so water temp is not a major hindrance.Do Carp breed in UK rivers. I read somewhere that the waters here are too cold for carp to reproduce.
Cheers Chris, this explains a lot. Having said that there are a few more carp showing on the Ouse in catches not that I've caught one. It made me question where these were coming from and if they were breeding successfully, and if they were then why weren't there more going back over the years. I did wonder if milder winters were a consequence of the apparent uplift in numbers. A friend told me after a flood the EA were called as there were some fish trapped in a recess on the flood plain, among them were 14 carp. If you consider that number were trapped how many are in the river itself. Does this suggest there are more than we think and they have been successful at breeding in there. Questions, questions and much speculation.Plenty of carp spawn, in all kinds of waters, yet they never see successful hatches. In my part of North Yorkshire, I can only recall one stillwater where carp reproduced successfully with any regularity. Most places it's a case of once in a blue moon, or not at all. Perhaps a few more have successful hatches, but the resultant fry never reach the level of maturity required for anglers to notice. I've no doubt that carp will spawn every year in the rivers that they are present. However, the chances of a successful hatch is going to be slim. On rivers that have low carp populations, rivers that rise in upland areas, or the further north the river is, those slim chances are only going to be reduced further.
Last summer was probably the best ever chance for successful carp spawning. It's likely that for some waters their blue moon successful breeding year will become apparent in a year or two. I still wouldn't be putting any money on there being any baby carp showing up in the Yorkshire Ouse system rivers.
With the Ouse specifically, I suspect that there are more carp than most would speculate. However, in your 14 fish flood example, I'd guess that was almost an entire shoal from a specific stretch, rather than being just a small proportion of a much more significant population.If you consider that number were trapped how many are in the river itself. Does this suggest there are more than we think and they have been successful at breeding in there. Questions, questions and much speculation.
An excellent piece Chris. Thank you for sharing. Certainly food for thought. I had considered targeting Ouse carp but I could be waiting a while. I suspect the Foss basin would be an obvious location for them to inhabit out of the floods that and the marina at Naburn, all that flood water and winter temperatures I imagine would impact on fry survival rates. I"ll have a word with one or two tackle dealers see if they have any match reports of carp being caught in any numbers. I can't imagine We"ll ever have them in our rivers like they do in Spain. Could you imagine!!With the Ouse specifically, I suspect that there are more carp than most would speculate. However, in your 14 fish flood example, I'd guess that was almost an entire shoal from a specific stretch, rather than being just a small proportion of a much more significant population.
As to where the fish in the Ouse come from, I'd reckon on the vast majority of them coming from flooded stillwaters. Don't forget there are multiple tributaries. Most of them are not good river carp habitat, far too rocky. I suspect that a significant proportion of the carp that do end up in the likes of the Swale and Ure are going to end up down around York (and downstream) sooner or later. There's only one place on the Swale that I've seen carp. That place is the only one I've heard of where they have been seen more than once and the only place I've heard (and seen) of one being caught.
There's also a reasonable chance that some carp have migrated through the top end of the Humber from the Trent. Carp are known to be tolerant of saline estuaries for at least fairly short durations. Fish moving between the Dorset Stour and Avon, via the estuary, being a known example. It's also worth considering that some carp appear to have evolved legs, which can be grown and shed at will. You can never say never for a successful carp reproduction in the Yorkshire Ouse, but I'd suggest that the odds are stacked against it. When that is the case, it's worth looking to other more plausible reasons if numbers appear to increase without there being an obvious explosion of tiddlers preceding it. Perhaps if global warming is genuine and accelerates, the chances will increase. However, the increase in flooding might just limit the effect that increased water temperatures may bring.