An author's choice of name for characters can often be suggestive of theme or the role the character plays in the story. Let's see if this applies here:
The name Henning is a variant of Henry and means "home ruler".
but...there is a species of fish called hen-fish
and...the female salmon is known as a hen
Somehow I doubt those are completely irrelevant coincidences.
Hale is of Old English origin and means "hero; from the hall"
But the word hale means fit, healthy
Ah, but this can't be an accident:
Orvis, founded by Charles F Orvis in Manchester, Vermont in 1856 to sell fishing tackle is famed for its high-end gear and though it caters to hunters and other outdoor sportsmen as well is generally agreed to be synonymous with fly fishing.