Should trout be considered an endangered species?
Lord No. Trout are widespread species of fish in both hemispheres.
"All species of trout" is indeterminate. Do you mean the ones in the genus Salmo? Those are the real trout (although the genus includes the Atlantic salmon) or are you including Salvilinus, which includes the brook trout but is more correctly referred to as chars? And then there are the fishes that bear the common name "trout" but are quite unrelated. Guessing that you mean both Salmo and Salvilinus, I can say that no species being bred in hatcheries is "in immanent danger of extinction". There might be a few wild populations in trouble but not species.
trout is not a species. It is a great number of species. Your assignment must have included more data which, perhaps, is fictional and just for the sake of the assignment.
I wouldn't doubt it in the longer run. Look at the oysters which used to grow abundantly in New York Harbor. now gone.