You are very welcome Captain and please see the additional information that may explain the answer to your question.
 
 
 
Approved Trout Waters Open to Year-Round Fishing [view regulation]BUTLER
Harbar Acres Lake
ERIE
East Basin Pond – Waterworks Ponds, Presque Isle State Park 
Lake Pleasant
Upper Gravel Pit
West Basin Pond – Waterworks Ponds, Presque Isle State Park
FOREST
Tionesta Creek – from Tionesta Dam outflow downstream
LAWRENCE
Bessemer Lake
Cascade Quarry
MERCER
Shenango River – outlet of Shenango Dam downstream to Buckeye Drive Bridge (SR 3025)
VENANGO
Two Mile Run Reservoir (Justus Lake)
WARREN
Chapman Dam Reservoir
 
Not certain...........  just guessing but, I wouldn't put it past those charged with the stocking program(s) thinking, the walleye angler has the lake and the trout angler gets the river.
 
 

 Thanks' again.....I know they do put more Trout numbers in the Shenango over the past 4-5 years but that Walleye fishing was a huge draw over the years. They get a program that works and brings in more people to fishing and wham they ditch it ! Just don't understand how tossing a few thousand Walleye fry in every year and seeing such good results and returns is being scrubbed. The natural return is way to low to keep up good fishing. That river has always been a good Walleye fishery it's a shame to see it wasted on only Trout. Both Trout and Walleye have been the reason Shenango River is well known in Mercer County. The Fish Commission needs to step up the Shenango River Walleye stocking program not eliminate it here ! They also need to get the Stripers in Wilhelm Lake and quit making excuses for all those Shad. More species of game fish = more fishermen !   

I've been trying to locate a story I read, I'm thinking it was in the "PA. OUTDOORS", and needless to say I can't find it.  Anyway the article was about a biologist admitting the PGC had decided to scrap a plan trying to to create a "lake specific fish" situation with PA. lakes. 
 
In NW PA., Wilhelm was targeted for bass, Pymatuning for walleye, Shenango for striper, etc.
 
We know the PGC has been busy creating 'fish habitat' at these lakes and have plans to continue to do so.  Whether this 'fish habitat' was fish specific only the PGC knows.
 
We know that Wilhelm was (for lack of a better word) POLLUTED with shad for several years.  Of course this was blamed on the fisherman releasing bait (dang BassMasters, anyway(lol)).  However, I thought there was a significant reduction in the numbers of shad last year.  Of course this may have been a 'figment of my imagination' or just 'wishful thinking' but here's hoping this year we see even less.
 
Speaking of seeing less of over the years, and again a possible 'figment of my imagination', is the aquatic weeds.    Especially the weed that are not a natural habitat to a specific fish.  But, silly me, who needs weeds when the PGC is providing habitat for the fish?
 
We also know the walleye fishing took a BIG downfall at Pymatuning with some (I said some) improvement in numbers (not necessarily size) being reported by the Pymie angler community this past year.  While the walleye stocking at Pymie is a co-op between OH. and PA.; I recall a story about PA. opting to stock fingerlings over fry for a year or two.  Mortality of the fry was the reason for the change and the PGC figured the bigger fingerlings would have a better survival rate.  Guess that didn't work cause their back to fry, as I understand.  Again, not sure of the exact year(s) and/or number of fingerlings stocked only, there was far less fingerlings then fry.  Since then, the fishery is showing improvement.
 
I can't close without mentioning the water temps. (this was changed to stress from spawning) being the 'said reason' for seeing large numbers of certain fish kills and or reduction of other fish size/numbers.  I'm sure the weeds have nothing to do with keeping the water cooler or providing oxygen.
 
Who am I to doubt the word of a biologist, so the only thing I can see that would have caused the change(s) we 'old timers' have seen................. must be Climate Change!