By Graves Lovell, Southeastern Pond Management

Here at Southeastern Pond Management, the most exciting and enjoyable management tool we use, hands down, is electrofishing. Beginning in very early spring, we perform electrofishing evaluations on ponds nearly everyday and there is never a dull moment. Many of our customers are familiar with this method of collecting a fish sample. However, we wanted to take this opportunity to answer some of the most frequently asked questions about electrofishing:

“How does it work?”
A generator mounted in the boat creates an electrical current that is sent to a pulsator. The pulsator can regulate the current in many different ways. Pond water can have varying levels of water conductivity; therefore, certain modifications to the current may be made by the pulsator to ensure fish can be collected. For our application, we usually set the pulsator to send out 60 to 120 pulses of DC current per second. The electricity leaves the pulsator and goes to the anodes (positive) which are lowered into the water in front of the boat. The current then runs through the water and back to the boat (negative). This creates an electrical field between the anodes and the boat that temporarily stuns fish along the way.

“Does it shock all the fish in the pond at once?”
No, an electrical field strong enough to stun fish is created just in front of the boat. This area is called the effective electrical field (EEF). The current quickly dissipates away from the front of the boat, depending on the water conductivity. Under normal conditions, the EEF has a radius of about 8 feet from the center between the two anodes and can reach fish about four to six feet deep.

“How many volts are coming out of that thing?”
The maximum operating range is 1,000 volts; however, to collect a good fish sample, we usually set it to operate between 300 and 500 volts with a current draw at four to five amps.

“Does it work in saltwater?”
No. The water conductivity is too high in saltwater. In other words, the high density of salt ions in saltwater allows the current to spread out too quickly to stun fish.

“Are some fish easier to shock than others?”
Some species seem to be more sensitive to electricity than others. Most sport fish, such as bass, bluegill, shellcracker, and crappie are easy to find and collect with electrofishing equipment. Other species, such as grass carp and tilapia, are more difficult to sample. Catfish are easily stunned; however, they are not collected as often simply because they usually lurk below the effective electrical field. On bright, sunny days, schools of shad often swim too deep to be collected as well.

“Does it harm fish?”
There is a myth that fish collected in an electrofishing sample become sterile. Not true. It is extraordinarily rare for bass or bluegill to be harmed. Cold-water species, such as trout, are more sensitive to the electrical current. While it is rare, trout are sometimes injured.

“How about snakes?”
Fish tend to surface when shocked because of their swim bladders, which make them easy to collect. Other vertebrates, such as frogs, turtles, and snakes, often go unseen because they usually sink slowly when shocked.

How Electrofishing Helps to Manage Your Pond
Electrofishing is fun to observe and it gets people involved and excited about their ponds. Its greatest benefit, however, is the incredible impact it has on pond management.

Initial Evaluation
Our initial visit to a pond usually requires an electrofishing evaluation to collect some baseline data describing the fish population and other pond characteristics. This evaluation allows us to make decisions that will improve the fishing experience and help meet the pond owner’s goals. From the fish sample collected, we determine the state of balance between predators and prey for the entire fish population. This is done by quantifying the relative abundance of predator and prey species within different size ranges. We also analyze the condition of the adult fish we collect. In addition, we evaluate other pond characteristics such as aquatic weed growth, water depth, water control devices, dam construction, fish structure and water fertility levels. Back at the office, we compile a comprehensive management plan designed to help each particular pond meet the owner’s objectives.

Annual Check-ups
Annual electrofishing evaluations are a great tool to impact of ongoing pond management activities. We usually recommend evaluations annually because the dynamics of a fish population can change quite a bit in one year. These check-ups allow us to document the condition of the pond and make any necessary changes to the management program. Some of our customers chose to super-intensively manage their ponds. We frequently electrofish these ponds more than once a year.

Electrofishing Bass Removals
One of the keys to restoring or maintaining a balanced fish population as well as promoting trophy bass growth is the selective removal of bass. In larger ponds, harvesting enough largemouth bass with hook and line can be quite difficult. Selective bass harvest through electrofishing can be an effective tool to help keep the bass population in balance.

Electrofishing evaluations can help the pond owner understand the dynamics of a pond while providing him the opportunity to “see” the pond management principles at work. For ponds with multiple users, electrofishing evaluations are a good opportunity to get everyone excited about the management practices. So, if you have a new or old pond that has never been managed, or you just want to see how your management efforts are paying off, give us a call to schedule an electrofishing evaluation. If you are like most pond owners, it will be an experience you will thoroughly enjoy.