To understand what the Salmonid and Resident fish require from their habitat in the Basin we first must understand the life cycles of these fish, when they are in the various reaches of the rivers, and what part of the life cycle they are in at a given time.
(we; must understand; the life cycles of these fish; T:when they are in the various reaches of the rivers; T:first) (they; are; in the various reaches of the rivers) (they; are; in; T:at a given time)
we they they
must understand are are
the life cycles of these fish T:when they are in the various reaches of the rivers T:first
in the various reaches of the rivers
in T:at a given time