Imagine for a moment what fishing was like during the Civil War in New Jersey.
Maybe some Pickerel, American Shad and Brook Trout, Yellow Perch, throw in a few Lamprey and Eels.
Look at the list of Native and introduced.
There are 90 species of freshwater fish found in New Jersey waters. Of these 90 species, 60 are native to the state. Five species are truly migratory and are present only seasonally in fresh waters of the state.
There are 17 introduced species, 11 of which are popular game species, a number of which have become naturalized and are commonly found in both lakes and rivers throughout the state. Several species, such as Channel Catfish, Hybrid Striped Bass, Muskellunge, Northern Pike, and Walleye, which do not reproduce as readily in New Jersey, are maintained through active stocking programs for recreational opportunities.
We could say the stocked Brown Trout are invasive to the native Brook trout and have "displaced" them, such as the recent electro-shocking on Rhinehart Brook to get rid of the Brown Trout.
https://www.njfishandwildlife.com/chkfish.htm
