Concerns about Bullhead and Brook Trout

Hello, I should probably start off by saying where I'm from. I live in New
Brunswick, Canada. I was fishing for brook trout today in a stream not too
far from my house and as soon as I got to one of the pools, I noticed some
considerably larger fish (1.5 to 2 feet long) swimming near the bottom of a
section that's about 6 or 7 feet deep. Anyway, my first reaction was, "man,
if those are trout, I want them." On closer inspection, I noticed the
barbels on the chins, fin arrangement, etc. and I think they're brown
bullheads, which are native to NB. Anyway, they didn't move much and I even
dragged my hook across one of them and it barely flinched. My
concern/question is the fact that they're living in a stream that hasn't
(it's been a few years since I've visited this particular stream) had
bullheads in it and the fact that the temp. requirements for trout and
bullheads are considerably different, could it be that the stream is warming
up? The river that the stream flows into has smallmouth bass showing further
up the river than normal as well. It used to be that it only had bass near
the mouth of it, as it flows into a larger river.

I was also under the impression (I've never fished catfish before) that
they'd be attracted to similar bait used for brook trout. I'm using worms
with a sinker. Anyway, none of them seemed the least bit interested..
probably because of the time of day though (around 3 pm). What time are good
to fish for them and with what bait?

Anyway, not sure if anyone's got any input on this or not. I just figured
I'd throw it out to see what people's opinions might be. Thanks.

Mark Currie