Skip to main content

Biologists often arouse the curiosity of onlookers while using this freshwater fish sampling technique.

As the name implies, an electrofishing boat applies electric current to the water to collect fish in freshwater systems.

An electrofishing boat uses a generator to produce electricity. The electricity travels to the poles, called booms, at the front of the boat and into the water. The electric field does not kill fish but temporarily stuns or impairs those that swim within a 6- to 8-foot radius from the booms. The fish can then be scooped up and handled with little stress or injury.

Its effects on most fishes are typically minimal. If done properly, this sampling technique can be much less damaging than methods that entangle or trap fish, which may injure or even kill them. Electrofishing also does not harm the eggs of female fish; in fact, the FWC uses electrofishing to collect females for breeding at the state hatcheries.

Depending on the sampling objective, biologists may collect data on every fish collected or just certain species. In most cases, biologists measure and record each fish’s length and weight and release it back into the water. They may also collect blood samples or tag the fish as part of ongoing studies. In some cases, fish are not released but kept for laboratory studies to determine age or collect information such as mercury and pesticide levels.

Several factors contribute to how long the current stuns the fish, including the species and size of the fish and the temperature of the water. In most cases, stunning occurs within the first few seconds of entering the electric field and lasts from a few seconds to several minutes.

A biologist at the front of the boat has control of the pedal switch that releases the electricity. If the biologist’s foot comes off the pedal, the power automatically turns off. The driver of the boat can also shut down the power in an emergency. The research team takes appropriate safety measures to prevent injuries.

No. The conductivity of saltwater is higher than the conductivity of the fish. In saltwater, the electricity goes around the fish instead of through it, rendering this technique ineffective for fish collection.

No. It is illegal for anglers to use electricity to fish.

Biologists will respectfully keep their distance to avoid disturbing anglers. However, if you have questions, you may approach the boat if the generator – which is quite loud while operating – is off. You may also approach FWC employees near boat ramps when they are launching or loading their boats. They can answer your questions and give you information about your local lakes and rivers.