Invasive aquatic species in Louisiana: recognize pathways and prevent spread

A native species belongs to the region’s ecological history. An introduced species has been moved beyond that context, while “invasive” describes introduced organisms that cause harm or spread in damaging ways. An unfamiliar or large native fish is not automatically invasive.

Alligator gar provide an important example of why identification matters. Do not remove or kill a fish because it looks unusual. Use the responsible agency’s current species material and retain uncertainty when a photograph cannot establish the identity.

Aquatic plants, fish and other organisms create different problems and need different identification resources. LDWF’s aquatic-plant guidance describes management of plants including invasive species. A thick floating mat should prompt careful equipment inspection, not an improvised chemical treatment.

Separate recognition from management. A visitor can avoid carrying plant fragments without knowing every plant name. Herbicide selection, release of control organisms and removal programs require authority and site-specific expertise; this guide does not authorize do-it-yourself treatment of a public waterbody.

Inspect the trailer, propeller, anchor, net and any recess where water or plant material can remain. A boat that looks clean from above may still carry material underneath. Live bait and bucket water can also transport organisms between otherwise separate waters.

Keep the pathway in mind when combining a freshwater morning with a coastal afternoon. The issue is not only the hull: boots, waders, coolers and small paddle craft can move wet material. A short transition between nearby sites still deserves the same inspection.

Apply the clean, drain and dry routine before the next waterbody. Remove visible material at an appropriate disposal point, drain retained water according to site rules and allow the equipment to dry. Follow any facility-specific decontamination requirement.

Do not release unused bait or aquarium organisms into the wild. Keep catches, bait and equipment organized so the final cleanup is straightforward. If moving live organisms is part of a lawful activity, confirm the exact transport requirements rather than assuming that a valid fishing license covers every movement.

For an unfamiliar organism, record the location, date and photographs that can be taken without handling or spreading it. Consult LDWF or the relevant land manager for identification and reporting direction. Do not carry a live specimen to another lake to show someone.

A report should distinguish observed evidence from a population claim. One photograph does not establish a new statewide invasion or a treatment recommendation. Keep the outing useful by improving prevention and documenting the find carefully, while leaving management decisions to the responsible authority.

An angler retrieves a kayak with unfamiliar vegetation caught near the rudder. Before driving to another launch, they remove the material at the appropriate disposal point, inspect the rest of the equipment and follow the site’s cleaning instructions. A photograph and location note support a later inquiry without transporting the organism.

This guide combines the references below with practical planning recommendations. Examples are hypothetical; they are not recorded outings, catch forecasts or verified tour products. Agency rules, closures and access notices must be checked for the date and place of your outing.

• LDWF aquatic plant and habitat management
• USFWS alligator gar
• LDWF freshwater finfish and crawfish