I am not sure if they still plant fish at Crater lake. If you have spent much time fishing you will pretty quickly learn that almost every accessible lake in the US is regularly stocked with fish.
I would say the "native" freshwater fish population is so decimated at this point that if you want to catch something you either seek out inaccessible places that have seen little human contact, or you follow the fish plantings and catch planted fish. The idea of a lake that thousands of humans regularly access having a healthy ecology seems far fetched.
They do not stock the lake anymore, no. The fish currently in it are considered invasive by the park and there are no catch limits.
It's odd the article poses this as a "problem" in an article about Crater Lake, where uniquely among lakes this "problem" is most likely to just fix the other problem.
Kill all the fish in the lake and the lake is better off.
It won't selectively kill fish, it'll kill frogs, turtles, algae, and anything else that lives in the water which isn't a bacteria or archaea capable of living in an anoxic environment. Possibly also the predators of those species which live on land.
> it'll kill frogs, turtles, algae, and anything else that lives in the water which isn't a bacteria or archaea capable of living in an anoxic environment
That's a bit dramatic. Frogs, turtles, salamanders, etc, can breathe air.
The only predators are birds, who can find food at any of the many other lakes in the area.
Crater Lake's geography is essentially unique among lakes that may be having this issue. There is a near-total lack of native fauna that would be affected by an anoxic event.
I would say the "native" freshwater fish population is so decimated at this point that if you want to catch something you either seek out inaccessible places that have seen little human contact, or you follow the fish plantings and catch planted fish. The idea of a lake that thousands of humans regularly access having a healthy ecology seems far fetched.