[Paal Gulli]

"... extinct in the Atlantic for 200 years, ... "

Extinct is an absolute. It is or it isn't. There's no such thing as "extinct in one location but extant in another."

[Harmless Teddy Bear]

There's no such thing as "extinct in one location but extant in another."

Tell that to the Pacific Salmon. It is the only "endangered" or "extinct" fish that is available in supermarkets every where.