Complex sentence: Exacerbating this is the fact that intensive human use of grizzly habitat coincides with the seasonal movement of grizzly bears e.g. in the fall, when grizzly bears congregate near streams to feed on salmon when anglers are also intensively using the river.
Split into simpler sentences: Exacerbating this is the fact that intensive human use of grizzly habitat coincides with the seasonal movement of grizzly bears. An example of this intersection occurs during the fall season: grizzly bears congregate near streams to feed on salmon when anglers are also intensively using the river.