Invasive species in Georgia
An invasive species is an organism that causes ecological or economic harm in a new environment where it is not native.
Over the years, humans brought in plants and animals and either intentionally or unintentionally allowed them to get established in an area where they are non-native. Organisms that were thought to be something good because they thrived in their new environment often succeeded so well that native species lost in the competition to survive.
There are many plants and animals that we see every day that are so common that we think that they have always been in our wonderful state of Georgia. English ivy and goldfish are both invasive species.
English ivy, if not contained, will kill trees, destroy the finish on the side of houses and smother out native groundcover. Goldfish have been released by kids into ponds and creeks and have reproduced and grown in size, becoming a major concern from Michigan to Miami. A member of the carp family that can grow to 9 pounds, goldfish very often survive and flourish in any freshwater body. Being primarily a bottom feeder it consumes eggs and fish fry of native fish, and have in some cases totally displace the natives.
Everyone in the south knows both kudzu and privet. In the past 30 or so years, I have battled both of these invasive plants. These plants have so dominated the woods near my house that they have caused over 40 trees to die, with several falling on a main power line causing outages for over 60 neighbors.
I can now say I am winning the battle. I have almost totally eliminated kudzu from my land and now, with the cooperation of adjoining neighbors and a herbicide called Crossbow, I hope to have things under control by next year.
A note to those who have privet hedges: Please keep them trimmed, and cut off all bloom spikes before the berries form. Birds eat the berries and spread the plant everywhere. There are hundreds of plants and animal species in North America that are invasive.
ARE TROUT INVASIVE?
The answer is yes and no. The most caught trout in North America, the rainbow trout, is invasive in many areas, primarily east of the continental divide. Native only to the west coast of North America, the rainbow trout is now found in all the contiguous states of America that have water that is cold and clean enough for the fish to survive.
When logging and other habitat destruction in the late 1800s and early 1900s began to displace, and often totally destroy, populations of brook trout, the powers that be decided to restock the now degraded home streams of the brookie with the larger and more prolific rainbow trout. The brook trout were sometimes eaten by or just could not compete with the invasive rainbow. Many populations of brookies were wiped out.
The brook trout is the only trout native to the Appalachian Mountains. Many anglers often claim that they caught a native rainbow. Truthfully, the streamraised rainbow trout is best to be called a wild rainbow.
Over the years, both rainbow and brown trout reproduced and have self sustaining populations in many areas, including many North Georgia streams. These fish are invasive in that they have totally displaced brook trout in many streams in Georgia and elsewhere.
Brook trout have been stocked in streams outside their native ranges. They have taken over in some streams out west and are such a nuisance that regulations in some watersheds now have no limits on taking brookies — and many do not allow catch and release of brook trout.
BRINGING BACK THE BROOKIE
The U.S. Forest Service, Georgia Department of Natural Resources and Trout Unlimited are taking steps to make sure that isolated brook trout populations are not being impacted further by the invasive browns and rainbows.
In places where all three species are found, fish migration barriers and natural barriers are used to make sure that fish cannot move upstream above a certain area. The invasive fish are usually netted or by other means caught and moved downstream of the fish barrier, which leaves the brookies in a stream with little or no competition.
Even in streams with self sustaining, natural reproducing browns and rainbows, Trout Unlimited’s philosophy is to protect the wild populations by not stocking “hatchery” fish into the streams wild trout populations.
TU MEETING
The next meeting of the Coosa Valley Chapter will be Thursday, April 28 at 6:30 p.m. at the ECO Center at Ridge Ferry Park in Rome. We will have a swap meet of fishing and camping equipment. Feel free to bring any gear other than boats and outboard motors. The public is invited.