Topic: Fish behaving strangely

[Gardengirl]

We have about 18 fish in our pond and for the past two or three days they have not surfaced. Normally when I go to the edge of the pond they are up there asking for food but now they are all staying at the bottom.  Any ideas anyone what can be causing this behaviour :-\

[Tyke]

Could be that local cats have taken a fancy to them and have been hanging around - made my fish very jumpy for a few months and i had to scare cats off a lot until they got the message.

Or it could be  areaction to the heat - perhaps they are seeking shade. The bottom of a pond or pool is a more constant temperature than the surface. When fish are at the surface a lot and opening their mouths it is often a sign of very low oxygen levels  and they are gasping for air. This happens a lot in very sunny and hot temps...

[silly billy]

Maybe a heron?

[lillian]

Ours disappear for days when there's been a heron about.

[Gardengirl]

Thanks for replies.  I haven't seen the Heron recently but I know they are about.  Maybe that is the reason.

I think there is plenty of oxygen Tyke as they have not been gasping, we keep our pump running constantly.

[Carol]

I agree with the others, mine used to go to the bottom after a Heron visit.  Either that or they are cold? but thats not possible down your way Pat. 

 :o

[GrannieAnnie]

Ours also hide after a heron visit. It helps them to have a board or something deep to hide under.

[Gardengirl]

I'm afraid you may all be right about the Heron.  We have been trying to see the fish but can only spot about 6 of them.  I thought that when a Heron visits a pond they usually clear out all of the fish in one go or so I have been told by others.  A friend lost all their large Koi Carp in one foul swoop :o

[Tyke]

We had heron around our pond a lot and so netted it over winter. A lot of mags and books say to remove the net in March. However, we had one back on our roof looking ready to pounce in June.

|I think that the missing fish does indicate a heron...

[Gardengirl]

I am pleased to say that the fish have all now surfaced again.  Strange how they disappeared for days.  As GrannieAnnie suggested we have made a hiding place for them just in case the Heron returns.

[Black Forest Dan]

Thanks to all of you, this probably explains why our fish are hiding too!

We actually saw a heron standing beside our pond, and we chased it off - don't know whether it actually got any fish, because they usually hide very quickly when we approach the pond anyway, so I can't imagine the heron would have got very lucky- there is plenty of cover (water lilies) and loads of hiding places (big rocks with big gaps to hide in) but what we couldn't understand is why they hide for so long;  they must be really spooked!

We're pretty sure they are still (nearly) all there, since they still eat the usual amount of food, but instead of eating it in broad daylight, they wait until it's dark now. We probably have well over 50 fish and they're breeding well so we are confident they're comfortable in general.

I had the idea (urban myth?) that fish had a short memory, so I was surprised how long they're taking to get over their fright from the heron... it's about a week now and they're still very timid... what makes it so surprising is that yes, they always "splash and dash" for cover when we approach, but they're usually back out again a few minutes later, even after something more disturbing like using a net to tidy up the pond - but after a heron visits, they're hiding for days, even on the sort of sunny days when they would normally be out sunning themselves! Can they recognise a heron, and remember for so long?

Dan.