Bream an oily fish

Came across something I have never seen or noticed. Been catching large coppernose bluegill and yesterday, I filleted some. The meat looks greasy, oily. Is this normal or common? Ever seen this? BTW, when put into a pot of water, yes, oil shows on the water surface. I just wanna make sure everything is good regarding it being ok to eat these fish. The lake has fish feeders and an elderly man told me the fish would taste bad, like fish food, instead of fish if I caught them near feeders. But I was not near a feeder. The ones I cleaned the old-fashioned way, scaling and gutting, they tasted fine to me. Although, the skin was tough and rubbery but I am wondering if maybe I fried them too long. Fried them in vegetable oil and used corn meal coating.

Also, this is the first time I have ever caught or cleaned coppernose species of bluegill, so, wondering they are different meat-wise from regular bluegill.