There is plenty of breaking news on prominent invasive fish species: Asian carp infiltrating the Great Lakes, snakeheads spreading in the mid Atlantic and southeast, and lionfish populating the Florida coastlines. In earlier decades, the news of invasive fish species included lamprey eels, which threaten northern trout and salmon species, as well as gobies, ruffe, and rusty crabs that highlight the Great Lakes’ small fish populations. Not to mention such non-fish invasions as the now widespread zebra mussel, plants such as water hyacinths and yarrow, and numerous other aquatic and non-aquatic organisms.
The problem in brief
Invasive fish are fish species that – mostly intentionally or accidentally – have been introduced by humans into habitats where they are not native. You could say that they are fish that appear in places they do not belong to. They are called invasive because they often become a means of reducing biodiversity, disrupting the balance of ecosystems, and altering critical habitats for other fish and fauna.
Invasive fish species were introduced through the transport of fish or larvae in the ballast of sea freighters, the unloading of bait buckets by anglers, on the soles of waders and boots, and as invisible hitchhikers on small boats and boat trailers. You may have escaped from one location and traveled to another by swimming through canals, locks, and other waterways. They were introduced by people who dumped them from personal aquariums, through experimental stockings, and in many other ways.
Some invasive fish species are well established in America more than a century after they were first introduced. The popular carp and brown trout, for example, do not come from North America. Some natives, such as largemouth bass and rainbow trout, were deliberately and widely introduced into states and waters where they were not naturally found. Still other native species, like white perch and blue catfish, have somehow appeared in places they shouldn’t be.
Some fish introductions were not beneficial. Many invasive fish species are overtaking their new homes and displacing native species. Once established, they are extremely difficult to get rid of. Florida officials are now desperate to keep lionfish at bay and the battle for control of the snakeheads appears to be essentially lost, despite anglers being urged to fish and hold both species.
What anglers can do
When you buy a fishing license, some of your money will help fund the state fisheries agency’s efforts to combat invasive fish. But your commitment doesn’t end there. Here are steps you can take to make sure that you are not part of the problem.
- Do not intentionally move fish from one body of water to another (which is illegal in most places without permission).
- Empty a bucket of bait on land before leaving the water. It’s okay to throw the bait back into the body of water once you’ve collected the bait there.
- Do not transport bait obtained in one body of water to another.
- Before leaving the water, inspect the boat, engine, trailer parts, and wet boating equipment and remove all visible debris, including dirt and mud.
- Drain the habitats, bilge water, and mirror wells at the access point before exiting the body of water.
- Use a hose, preferably a high pressure spray, out of the water to clean your trailer and boat.
- If zebra mussels and prickly water fleas are known or suspected, wash your boat, device, trailer, and other equipment with hot water when you get home. Flush water through the engine’s cooling system and other parts that get wet. If possible, let everything dry for at least three days before moving the boat to another body of water. Rinsing with chlorinated tap water can help.
- Learn and follow the recommendations of the state fisheries agency about keeping any invasive fish you catch.
Finally, read this in-depth guide to cleaning your equipment from the Pennsylvania Boat Commission and make sure you have an up-to-date fishing license.