Electrofishing FAQ

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

If you spend a lot of time on Florida’s freshwater systems, you may have seen the FWC’s electrofishing boats in action. Biologists use these vessels to gather information about freshwater fishes. These are some of the questions they often receive.

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

electrofishing boat, caption below
Biologists using electrofishing to collect fish.

How does the electrofishing boat work?
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.

Does electrofishing hurt the fish?
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.

What are you doing with the fish?
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.

How long are the fish stunned?
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.

What happens if a person falls into the water during electrofishing?
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.

shocked bass being weighed and measured before release, caption below
An FWC biologist measures the weight and length of a bass
collected by electrofishing.

Can you use an electrofishing boat in saltwater?
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. 

Can I use electricity to fish?
No. It is illegal for anglers to use electricity to fish.

Is it safe to approach the electrofishing boat?
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. 



FWC Facts:
A shrimp escapes predators by quickly pulling its abdomen in toward its carapace (body). This motion shoots it through the water backward.

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