Professional water management takes place both on large public waters, such as the Great Lakes, Lake Tahoe, and the Mississippi River, and also on small private waters including private ponds and lakes. The purposes of water management are varied. One objective is to check the health of the fish populations and to make sure that no invasive species have been introduced.
Invasive species are fish or other species that are not native to the geographical waters. Because they are not native, they have no natural predators and so can rapidly multiply and take over an ecosystem. This destroys the natural balance and affects all the species in the ecosystem. One of the most familiar instances of this is in the Everglades. An exotic snake species, the python, is taking over the natural population, killing even alligators.
A similar type of thing can happen when a non-native species of fish is introduced into waters. In order to make sure that the native populations are not overcome, lake management professionals employ electrofishing surveys to see what is happening beneath the surface of the water.
Electrofishing temporarily stuns the fish. They are netted and brought into a research vessel where they are counted according to species. The type and health of the various fish populations is noted. Items such as the relative abundance of the fish, the weight, and the growth rates can be noted. The fish can then be returned to the waters. Of course, if a non-native species is found, an invasive species, it can be culled at this time. Further determinations as to the next steps can be taken.
In a private pond or lake, electrofishing helps the owner determine the relative balance of the fish. It may be that adjustments need to be made in terms of feeder fish, sport fish or food in order to have a health balance for good fishing. Certain fishing limits of how many fish per day may be taken may be established, even on a private lake, so as not to overfish. Another possible thing that may happen is that brood fish may be taken for spawning in tanks.
Electrofishing does not hurt the fish. They are briefly stunned, but recover shortly. Electrofishing does not hurt mammal populations either. Your lake management professional can do this type of service for you. They have the proper equipment and knowledge to successfully carry out this research operation safely.