Oh, I can just about guarantee they monitor it all even if they don't do anything about it. When I was at college, they knew that I was in the top 20 for bandwidth usage on the campus, but never complained about it.
IRC tends to get blocked more often than protocols that you might expect to be blocked at colleges and universities. I'm not entirely sure why that is other than perhaps they just don't want the "chat" options available (they tend to block IM clients a lot as well) but don't necessarily care about downloading. It's not unusual. Be happy that you still have access to those other protocols.