Nope... long cod is a saltwater species. They are called burbot.

The burbot (Lota lota) is the only gadiform (cod-like) freshwater fish. It is also known as bubbot, mariah, freshwater ling, the lawyer, coney-fish, lingcod, freshwater cusk, and eelpout. The species is closely related to the marine common ling and the cusk. It is the only member of the genus Lota.

Lingcod,(Ophiodon Elongatus) is a saltwater fish. That is a lake.