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Can someone please explain this behavior
Posted: Wed Jan 31, 2018 6:21 am
by Buller
This morning (for the second time) I observed literally hundreds of carp all lying almost motionless with their lips opening on the water surface. The fish were concentrated in a band reaching across the lake. I checked for bugs but I couldn’t see anything on the surface. I saw this same phenomenon week or so ago. I spend a while each morning bird watching here before work so I didn’t have my rod! It’s been pretty hot lately and not much rain. Any ideas lads?
Thanks, Buller
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 7:13 am
by DaceAce
Lack of dissolved oxygen?
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 9:43 am
by Snape
If it is hot then almost certainly lack of dissolved oxygen and they are trying to get it from the topmost layer where it is most concentrated.
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 10:19 am
by Dave Burr
Buller wrote: ↑Wed Jan 31, 2018 6:21 am
This morning (for the second time) I observed literally hundreds of carp all lying almost motionless with their lips opening on the water surface. The fish were concentrated in a band reaching across the lake. I checked for bugs but I couldn’t see anything on the surface. I saw this same phenomenon week or so ago. I spend a while each morning bird watching here before work so I didn’t have my rod! It’s been pretty hot lately and not much rain. Any ideas lads?
Thanks, Buller
What sort of water is it Buller? The size, depth amount of shelter such as surrounded by trees? and what was the temperature? All of these will help to narrow it down but I suspect, as Daceace has already said, it's lack of oxygen.
Nice to see you posting again by the way
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 6:49 pm
by Paul D
Snape wrote: ↑Wed Jan 31, 2018 9:43 am
If it is hot then almost certainly lack of dissolved oxygen and they are trying to get it from the topmost layer where it is most concentrated.
Fascinating Nigel! I never knew that, how does that happen?
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 9:01 pm
by Snape
Paul D wrote: ↑Wed Jan 31, 2018 6:49 pm
Snape wrote: ↑Wed Jan 31, 2018 9:43 am
If it is hot then almost certainly lack of dissolved oxygen and they are trying to get it from the topmost layer where it is most concentrated.
Fascinating Nigel! I never knew that, how does that happen?
In the uppermost layer there will be algae and phytoplankton which produce oxygen through photosynthesis and oxygen will be dissolving directly from the air, especially is the surface is disturbed by wind or splashing. It may not make a lot of difference to the amount of dissolved oxygen but enough for the fish to detect and head to the surface.
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 9:05 pm
by Julian
Its concerning Buller as you say its for the second time. If this continues for any length of time - more than a few hours, then the fish will most likely die through lack of oxygen.
Re: Can someone please explain this behavior
Posted: Wed Jan 31, 2018 9:56 pm
by Tengisgol
Pray for rain and a good blow I'm afraid.
Re: Can someone please explain this behavior
Posted: Thu Feb 01, 2018 10:00 am
by Shaun Harrison
Big winds are more important than rain and tunnels for the wind to cut through, such as gaps in the trees etc.
Heavy rain can create big oxygen crashes too.
Re: Can someone please explain this behavior
Posted: Sat Feb 03, 2018 9:42 am
by Buller
Interesting Shaun - I'd have thought that rain would have oxygenated the water