DovidBT
I dont know where you live, but if you read, you can buy Salmon and other kinds of fish that you can indentify from a non-kosher fish store, Ask your local rabbi how to do it
Actually, I looked into buying whole fish and cleaning/skinning/cutting it myself. But I couldn’t find any stores that have whole fish. Apparently it’s already processed when they receive it from their suppliers.
There are fishing spots in the area where I might be able to catch kosher fish, but that’s not practical for me at the moment.