What is this behaviour all about?

[Buller]

This morning before work I stopped by my little pond to have a little look at what was going on. I saw 3 or 4 carp on the surface swimming slowly in a tight ball. Their fins were out of the water and it looked as if they were frolicking. This went on for at least 15 minutes - I then had to leave for work. It's moved from spring to summer out here in SA and to be honest it's been as hot as hell over the past week. Are these fish spawning? Is this the behaviour carp display when spawning?
Help please team!
Cheers
Buller

[Shaun Harrison]

They are usually dashing around and chasing prior to spawning. If they are moving slowly it could be a case of an oxygen crash, are they gulping air, does it look like they are gasping?

[Trevor]

I've seen the same sort of activity here.
It was Autumn at the time so not hot, but it had been a dry spell and I wondered, as Shaun has suggested, if it was oxygen related.

[Buller]

The fish did occasionally gulp Shaun, but what was so strange is seeing three or four fish swimming slowly on the surface in such a tight ball. The other thing that I've noticed is that at around 8.00am each morning (when I stop for my mandatory look at the pond and some bird watching before work), there are good numbers of carp cruising slowly just under the surface - some even look like they're hoovering the odd thing off the top. Around mid morning they disappear and that's it. They only show themselves in numbers the following morning. Any ideas about this behaviour?

[Stathamender]

There's an interesting book by Daniel Bagur available from Amazon which goes into various questions of interest to people like us: Where the Fish Are: A Science-Based Guide to Stalking Freshwater Fish though I can't immediately recall if it covers this kind of behaviour.

[Shaun Harrison]

The fish did occasionally gulp Shaun, but what was so strange is seeing three or four fish swimming slowly on the surface in such a tight ball. The other thing that I've noticed is that at around 8.00am each morning (when I stop for my mandatory look at the pond and some bird watching before work), there are good numbers of carp cruising slowly just under the surface - some even look like they're hoovering the odd thing off the top. Around mid morning they disappear and that's it. They only show themselves in numbers the following morning. Any ideas about this behaviour?

Sounds to me from what you say above that they are probably simply enjoying the first rays of sun warming them, increasing their metabolism before getting on with life. If they are simply slurping along the surface and not obviously gasping there is little to worry about.

If the water is weedy then the morning is when the oxygen starts to replenish again. This is why the first few hours of daylight are often quite productive as life is coming back to the water they rely upon.

One signal of issues is to look at their dorsal fins whilst cruising around. If they are up and erect then they are generally very happy carp. The dorsals usually stay down when not in the peak of health.

[Buller]

Thanks Shaun