how genetic diversity can be sustained in emclosed water bodies?

Question

I was watching a lot of mountain fishing videos and i was wondering how the trout population can remain healthy and genetically diverse if no new trouts enter the gene pool?

In: Biology

Answer 1

very few lakes are truely enclosed. most flow out a river somewhere.

There are a few lakes where a fish gate has been put over the river, these are generally stocked by humans to give people fish to catch.

but its nor like you need that much foe genetic diversity, in general you only need 50 individuals to avoid inbreading, and 500 to avoid gene drift.