Since South Oromocto Lake is connected to the St John River through South Oromocto River, I wouldn't be surprised to see smallmouth in there.Please don't even mention smallmouth bass and S.Oromocto lake in the same sentence - I almost had a heart attack.
Nice trout lake, pretty heavily fished though. Best fishing is in the spring for the 1st month or two. Used to catch some dandies there years ago, there are still nice trout in it, but the avg. size has diminished greatly over the years..... not too many guys releasing any fish out there for some reason.