BE careful what you believe from Game Wardens and that group and any group really; including this forum. We try to produce the best, most accurate and up to date pond information but sometimes a few things slip past the Moderators. Green sunfish are notorious for getting distributed to all areas with water especially streams.
In my fish identification experience which is pretty extensive during the college years including a month looking at fish at the Fish Museum Univ of MI), your sunfish is not a pumpkinseed. This is why. The maxillary (aka upper jaw) of your fish pictured extends beyond the front edge of the eye. Look carefully. The maxillary of the pumpkinseed goes back only to the front of the eye. Tomelleri's images are very acurate.
http://www.state.me.us/ifw/fishing/species/identification/images/pumpkinseedsunfish.jpgNow your fish could have some longear sunfish genetics since it has the prominent emerald streaks on the gill plate and its mouth (upper jaw) extends past the front toward the middle of the eye as does the GSF.
