Are Largemouth Bass Invasive? Non-Native vs. Invasive Bass

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Largemouth bass catching the bait.

Largemouth bass are invasive in certain bodies of water across the United States. When introduced, they can eradicate native species, hurting those ecosystems. Native largemouth bass can be removed from bodies of water by invasive largemouths.

In freshwater, largemouth bass are near the top of the food chain. While their power and aggression make them exciting to target, they can cause a lot of damage. They can wipe out entire populations of smaller fish, amphibians, and crustaceans.

Invasive Largemouth Bass

Largemouth bass are native to the Eastern and Midwest regions of the U.S., but not every body of water has largemouths. I grew up fishing for them every chance I got in many of Minnesota’s thousands of largemouth bass lakes.

Whether introduced by birds dropping eggs from their talons or game and fish departments stocking new bodies of water, largemouth bass have become a staple in freshwater fisheries nationwide. 

Largemouth bass are visual feeders, so any food in any part of the water column is fair game. They multiply and become territorial almost immediately. Smaller fish populations, like sunfish, perch, and crappie, can suffer if there aren’t enough crustaceans or insects to eat. 

Largemouth bass eat these smaller native fish in high numbers. Because largemouth grow so rapidly, these smaller fish make for easy meals and fulfill a largemouth’s hefty diet.

Largemouth bass can also destroy natural cover and structure if they eat too much of the vegetation. This is an issue because smaller fish populations use this as protection.

There are examples in the United States of invasive species ruining bodies of water. Asian Carp were introduced into the U.S. in the 1800s, and since then, they have destroyed vital vegetation, smaller fish species, and insects in bodies of water across the country. 

I’ve fished in many lakes and rivers with signs posted everywhere to kill the carp we catch because they do so much damage.

Now, state game and fish departments are stuck trying to figure out how to remove them. 

While largemouth bass aren’t as bad as Asian Carp (yet), any invasive species can be a detriment to ecosystems in the U.S.

What to Do About Invasive Largemouth Bass Populations

Pay close attention to local laws when fishing in an area where largemouth bass are invasive. Certain game and fish departments ask anglers to catch and kill as many bass as possible. 

Other departments will take care of the invasive bass populations themselves without the help of anglers. 

Largemouth bass, held tight!

Invasive vs. Non-Native 

There is a difference between non-native and invasive fish species. While non-native fish have the potential to be invasive, it doesn’t happen every time. Non-native largemouth bass can help the bodies of water they’re introduced into. 

Non-Native Populations 

The introduction of largemouth bass in Long Lake in Michigan significantly increased the clarity of the water. They ate a majority of the plankton-eating fish, and zooplankton ate phytoplankton. The increased water clarity meant more oxygen and healthier fish populations. 

Largemouth bass can withstand poor water conditions, so they work well to clean up an unhealthy ecosystem. 

A removal of largemouth bass almost guarantees an increase in algae. Minnow populations increase, and they’ll eat zooplankton in large numbers. The lack of zooplankton means more phytoplankton and algae. 

Game and fish departments often put more largemouth in place to clean up the ecosystem. 

Largemouth bass in the water.

Frequently Asked Questions 

What do Largemouth Bass Do for the Ecosystem? 

Largemouth bass play a significant role in removing phytoplankton populations. Once phytoplankton and algae are gone, the health of the water increases and the fish have better living conditions.


Keeping top predators in check is challenging. A healthy native population of largemouth can help manage populations of smaller fish. Largemouth bass can help control smaller fish populations which, in turn, prevents them from fighting each other for food.

They can eat problematic insects, plankton, or other small creatures that are harming the ecosystem, but largemouth bass can destroy ecosystems when introduced into the wrong water.

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