Goldfish swimming upstream?

[Bluerooster]

My goldfish pond is in two parts. An upper pond, and a lower pond, connected by a stream, with falls. The bog dumps into the upper pond via water fall. Upper pond is about a foot deep. The stream is about 40 feet long, and at it's deepest point is about 2 1/2". On average it's about an inch deep. The stream dumps into the lower pond where the fish are via a waterfall. From stream to lower pond is about an 18" drop at the falls. Somehow, two of the younger goldfish made it up the falls, upstream, over another fall, and into the upper pond. Total distance of about 40 feet. I don't know why they would go to all that trouble, but they did.

 

[Mmathis]

They must identify as Salmon!

 

[BKHpondcritters]

Does the pump in your lower pond feed the upper bog/waterfall? If so they (either as eggs or maybe very small fry) could have gone through the plumbing. That's happened here on a couple of occasions - small fish have been found in our upper pool area & the design/height of the stream & waterfall make getting there by going 'upstream' impossible.

 

[addy1]

Same has happened with my ponds, fish show up in fishless ponds.

 

[Bluerooster]

It could be possible that they got pumped up to the bog. But they would have to make their way through about 12"-14" of pea gravel, to get from the pipe to the surface of the bog, then go with the flow over the falls, to the pond.

 

[BKHpondcritters]

To quote Ian Malcolm: "Life, uh, finds a way."

 

[PM-Performance]

Fish do funny stuff like that sometimes.
My smaller koi like to swim up my VERY small waterfall pool/stream.
Hardly seems worth the work to me, but I guess they think there may be something interesting up there.