Mountain lakes are completely different.

There’s fish eggs being washed everywhere during rain storms. The eggs come from upstream and wash into random places.

This doesn't provide an answer for lakes.

But I always thought the explanation was eggs randomly getting stuck to bird feet. Or maybe a bird carries a fish with eggs up there and eats it or something. Inevitably it happens though...

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wil421 an hour ago | parent | next [-]

Lakes have connected rivers and streams that provide paths for fish and eggs to move around. There are human and animal activities that affect this. Your bird example and beavers causing floods could allow movement.

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jmalicki an hour ago | parent | next [-]

Isolated alpine lakes do not have connected rivers and streams, yet a ton are stocked with fish by humans.

Is it unbelievable that ancient hunter-gatherers would do the same thing?

	▲	jerf 26 minutes ago \| parent [-]
		A lot of people are unaware of how much husbandry hunter-gatherers still did. They may not have been farmers, with field plantings, weeding, and harvest seasons designed to maximize every acre under production, but they weren't stupid and still spent time to bend the world around them to the task of providing them more resources than it would have on its own. On a bang-for-the-buck basis they often did better than the farmers, it's just that without farming you can't get that density and net return. This looks like a good overview paper for interested folk: https://pmc.ncbi.nlm.nih.gov/articles/PMC3048989/

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jjallen 32 minutes ago | parent | prev [-]

So many lakes do not have rivers flowing in and out. A low spot in an area will become a lake.

Many do have rivers; many don't. Ponds even more so don't have attached rivers.

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2 hours ago | parent | prev | next [-]

[deleted]

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darknavi an hour ago | parent | prev [-]

"Life finds a way"

- Dr. Ian Malcolm

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williamdclt 2 hours ago | parent | prev [-]

How did they appear upstream?

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wil421 2 hours ago | parent | next [-]

There’s a stream in my back yard that doesn’t hold fish over the winter because it’s too shallow/cold. A large property near me has a pond that overflows into my stream. The fish survive in the deeper waters of the pond and spring rain usually washes fish eggs or even fish into my stream. They gather in the rocks in my backyard near the storm drain.

Alpine lakes are fed by snow met. There’s not going to be fish eggs on the snowpack that melts into the lake.

	▲	kakacik an hour ago \| parent [-]
		You yourself wrote in this thread: > There’s fish eggs being washed everywhere during rain storms. The eggs come from upstream and wash into random places. Do you realize that in the summer mountains below 4000m are mostly snow-free and thawing point ie in Europe has been pushed above 5000m repeatedly during summers. Its easy to have 25C in 2500m in today's alps (ie today 22C in 2000m in Chamonix, France). The term 'alpine lake' doesn't mean anything specific, and most are fed from rain during entire summer without any/much of snow or ice contribution.

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ShinyLeftPad an hour ago | parent | prev [-]

A tornado?