From what I have been told, the lakes (anywhere) on the Island are not very good habitat for trout and even those lakes that trout occur naturally, the fishing's generally poor, with small fish. It has something to do with the lack of natural feed.

In the stocked alpine lakes,the fish don't generally reproduce and the stock may grow for several years, until someone catches a couple of big ones. Then word gets out and the next people find nothing... because the first fishers caught them all. I have heard of opinions to eradicate the stocked lakes of fish and to return them to their original state, but I don't have a definitive opinion myself .

Maybe someone with more knowledge of fresh water fish in Island alpine lakes could speak to this.

Peter