The brethren brown and rainbow trout varieties having been introduced by pale faced humans. In fact, the more prolific and aggressive rainbows oft replace the "brookies" at Appalachia's stronghold of the Great Smoky Mountains National Park (GSMNP) and elsewhere.
Fearful for the demise of the slow-growing, short living and less productive brook trout, researchers also had acid rain and global warming as newer kid on the block threats to the native coldwater fishery.
It's no wonder they feared the beautiful fish might disappear from the face of the earth.
Extra no wonder that fancier organizations such as Trout Unlimited raise the flag that says loud and clear, "Bring back the Brook."
The candy-stripe finned trout miniatures are true environmental indicators to boot.
That is, they hold out at some of the last best places with excellent water quality, streamside habitat and aquatic insect populations.
Yet their small stream homes are generally quite ticklish and somewhat sterile in nature.
A little of this or a little that to the negative one way or the other could knock a stream out of kilter. The fish might then disappear altogether or more commonly be replaced by pollution tolerant fish species, such as carp and creek chubs.
This is precisely how they have been losing ground at their battlefront for survival measured by the researchers in linear miles of stream inhabited. In an effort to save the lot, the Great Smokies was closed to brook trout fishing for nigh 30-years spanning from 1976.
That's when a lot of the research was conducted on every aspect of the brookie's life cycle.
The end of the three-decade span met with a host of fishing and no fishing comparison studies. Remarkably, the researchers found that very high mortality rates were normal and that fishing had no significant effect on the population.
So much for the 30-year moratorium in hindsight one supposes!
Furthermore, anglers generally release the ones they catch stating that they mostly just like to fish for the beautiful brookies, not fry them.
Studies in Virginia confirm the mostly benign angling impact. Fishing pressure was just representing a fraction of Mother Nature's normal heavy hand.
The angling had no other specific effects on average size, age or reproductive measures.
Major population declines were again decided by Mother Nature not by barbed hooks.
Instead, heavy spring rains that flush the just out of the yolk sac fish "fry" and summer droughts that killed many age classes outright or more readily exposed them to feathered, furred or reptilian predators, such as: kingfishers, raccoons and water snakes.
Aside from those natural disasters and in times of less extreme weather, the fish can apparently hang in there and take a licking from the fishing.
In the meantime, just follow the existing rules and regulations and get the required licenses that pay the bills.
Then GO FISH!