Freshwater Fishing

Largemouth bass as an invasive species

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Largemouth bass (Scientific Name: Micropterus [small fin] salmoides [salmo]) have become one of the more popular game fish among anglers in the United States and elsewhere. Anglers, old and young, in nearly every state in the U.S., enjoy trying their luck with these feisty freshwater fish. Except when out for a trophy specimen, most anglers consider just about every size and weight of the largemouth bass a prize worth fishing for. From eight inch youngsters to whopper-sized bass, the thrill of catching and the enjoyment of eating keep anglers returning again and again to their favorite fishing hot spots.

These hot spots, where angling success remains consistently excellent year in and year out, become so because of the proficiency with which largemouth bass reproduce and forage for food. In an environment where survival of the fittest reigns supreme, an efficient means of reproduction and food consumption equal longevity of a species. These two vital factors create in the largemouth bass, considered the top predator in aquatic ecosystems, a veritable survival machine.

In the spring, a male largemouth bass prepare special nests in shallow waters where the a female will lay 3,000 or more eggs. After fertilizing them, the male bass remains in almost constant guardianship over the ripening eggs and then over the young fry as they hatch and learn to find food, which consists primarily of plankton life and insect larvae. As to adult food sources, largemouth have a wide-ranging diet. They prey on all varieties of sunfish, shad, minnows, crayfish and other amphibious life, such as frogs and snakes, as well as the young of other fish that inhabit the same body of water. As they mature, largemouth bass prey on the offspring of pike, trout, striped bass and catfish.

The foregoing factors suggest the primary reasons why in certain circumstances bass can become considered an invasive species of fish. The large number of offspring that bass can and do produce, combined with their voracious and varied, across-the-board feeding habits, can make them a deadly force that can eliminate other species of fish.

This usually does not happen in areas deemed natural environments for largemouth bass. For instance, in the United States, largemouth bass commonly have inhabited lakes in most of the states east of the Rocky Mountains. Anglers now can find them in many suitable lakes in other states, such as California, Oregon, Washington and Texas. In these lakes, largemouth bass usually do not constitute a danger to other species of fish.

A threat has occurred, however, in some areas where largemouth bass are not indigenous, particularly in other countries. The known popularity of largemouth bass has led to their introduction into waters in several countries around the world. This has had unfortunate consequences for native fish and other aquatic creatures, as large schools of hungry bass roam the lakes and ponds in a continuous attempt to eat everything they encounter.

The depredation may unfortunately prove irreversible. Native stocks may not fully recover from the predatory activities of the introduced largemouth bass. The bass themselves eventually may disappear as the ravenous adults feed upon their own offspring.

More about this author: Lane Olinghouse

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