About the buyer’s guide
There are several factors to consider when selecting the appropriate or optimal electrofishing equipment for your sampling conditions. Gear varies in range of application, particularly the effective water conductivity range that can be successfully fished. Models vary in the choice of electrical outputs and the degree of control you have on those electrical outputs. This is an important consideration when, for example, sampling sensitive species of concern (as Brook trout). Accurate output metering is important for standardization and your learning process. The electrofishing.net Buyer’s Guide contains our recommendations for types of electrofishing units that have capacities that allow use in relatively broad conductivity ranges and have the controls and metering for adaptability, learning, and standardization.
For a video overview of factors to consider, see Equipment Selection.
These are just the units we particularly like, based on what we look for, and ones we’ve had the opportunity to test properly in the field and at the bench with an oscilloscope (you can test your own gear using the tools page). This is not meant to be an exclusive list – so, manufacturers, please get in touch if you think your unit should be on the list or if you would like to send a unit for an independent review.
Criteria for Choosing an Electrofishing UnitExpand the list of considerations
Most of these specifications are for control boxes (pulsators).
Here’s various equipment attributes that can give you the capability to improve capture efficiency and precision.
Power, maximum output average: backpacks typically are 200 Watts or 400 Watts average; control boxes for boat units range from 1,700 Watts to 9,000 Watts average and more. Higher power capacity can increase the upper range of water conductivities that you can effectively electrofish.
Waveform type: may have one of more of these types- alternating current (AC), direct current (DC), or pulsed direct current (PDC). Having all three options in a control box provides more capabilities for capture and fish trauma control; AC often extends operating range into lower or higher conductivity waters. DC can be very effective for attraction of fish to the anodes and often is less injurious to salmonids. PDC can be very effective while putting less power demand on your equipment. Some units have a special form of PDC, the gated burst or complex pulse system, primarily used to minimize fish injury potential.
Voltage and voltage control: Voltage maximums typically range from about 600 V to nearly 1,200 V. Higher voltages are needed in low conductivity water. Continuous or small increments (e.g., 1 Vpeak up to 5 Vpeak per selection) are desirable. Large increments (>= 50 V) can make it difficult or impossible to apply required outputs for standardization or reduction of fish trauma. A large voltage increment can result in the lower setting resulting in poor catch and the higher setting resulting in shutdown due to excessive power or current draw. Common maximums range from 600 Vpeak to 1000 Vpeak direct pulsed current, and up to 700 Vrms (AC); higher voltage can extend effective fishing range into lower water conductivities.
Amperage: maximum peak current typically ranges from 10 amps to over 75 amps in the higher power units, with the maximum near 600 peak amps in one U.S.-built control box; higher amperage capacity can extend effective fishing range into higher conductivity waters.
Frequency: Typically ranges between 7.5 – 120 pulses per second for PDC (50 or 60 Hz typical for AC). However, higher frequencies, as 300 pps, are showing promise for capture. Some units have capacity up to 1000 pps. The best option is continuously adjustable or fine control by 1 pps increments. Often higher frequencies, at least up to 120 pps, result in lower response thresholds and are more effective (i.e., less power needs to be applied for a particular capture-prone response). Concerning fish trauma, the ability to control frequency enables waveform management to lower fish injury potential.
Pulse width: Units range between less than a millisecond to 10 milliseconds or more; Typical applications use 1 millisecond or more (often up to 4 – 6 milliseconds); pulse width and frequency affect duty cycle.
Duty cycle: Best control is continuous (1% increments) from 1% – 100% (DC); Research has suggested that the optimum range of duty cycle for capturing fish ranges between 20 – 40% so a 40% maximum is sufficient in many cases, although higher duty cycles can increase attraction (taxis). Good control of duty cycle gives you the flexibility to adjust waveforms to improve fish reaction, particularly attraction.
Waveform shape: Shape can vary across models (e.g., capacitor-discharge exponential decay, square, rectified AC) for all three major waveform types. There has been limited research on comparison of capture efficiencies and potential for fish injury among different PDC waveform shapes. Square waves compared favorably in capture efficiency and lower fish injury and stress levels. “Rounded” PDC pulses from rectified AC appear to require higher power than square waves to sample at the same efficiency. The square shape also facilitates accurate metering and description (e.g., duty cycle). Note that square waves can have slanted tops or spikes when under heavy loading, as in high conductivity waters. An operational capacity analysis with a scopemeter can indicate how well a unit keeps the waveform shape intact under various levels of loading.
Metering: It is critical to have good peak reading meters; the best configuration is a peak reading output voltage meter and a peak output amperage meter; however, either a peak volt or a peak amp meter will allow you to standardize by voltage or amperage (of course, really power). If you have an average reading amperage meter, you’ll need a good duty cycle meter or a recently calibrated duty cycle control to convert average to peak. Due to wave non-symmetry, using RMS voltage or current meters for AC is not recommended. You’ll need a peak-reading voltage or current meter for AC as well. Without metering, assuming that the dialed-in values (setting) for voltage is equal to output may be problematic, particularly at high loadings (usually high conductivities); if you don’t have metering, the best option is to incorporate testing equipment (e.g., a scopemeter-current clamp combination to serve as the amp meter). Do not trust the setting value.
Electrodes: The design of electrodes is under your control and preferences. For DC or PDC and often AC electrofishing, typically you want the cathode to have larger surface area than the anode. High resistance can limit power output.
Operational Capacity: Here you are trying to answer the question: “What is the range of water conductivities that can be successfully electrofished with the unit under consideration?” (Do not rely on conductivity ranges given by manufacturers). First determine 1) the range of water conductivity that you will encounter and 2) the level of power required for successful electrofishing across water conductivity with a particular gear (use Excel files EF Goal Power or the Electrofishing Tool app). Note: a determination of successful electrofishing means that at a given water conductivity and using an effective waveform, you can generate more peak power than you need. Next, run an output analysis of your gear. You’ll need to input certain equipment specifications from the manufacturer and electrode resistance. Use the Excel files Boat Power and Backpack Power to estimate the effective electrofishing range across water conductivity. See the subsequent instructional videos for an analysis of capacity. The Trouble-shooting video contains a thorough demonstration (starting around Minute 15), then followed by the power analysis section in the Equipment Selection video .
Backpack Power Source: The choice of a power source source for your backpack is broadly battery versus generator. Typically, batteries and generators provide the same output power capacity. An advantage of batteries is that they are quiet, but if water conductivity is high, some prefer carrying gasoline for a generator rather than additional batteries. This said, in North America there is only one model that has a generator option, the Midwest Lake Electrofishing Systems “Xstream” backpack. If you prefer or are constrained to using batteries, then the choice is lithium versus lead-acid. Lithium are more expensive, but have longer discharge and longevity times. They are also considerably lighter in weight.
For an estimate of battery shocking time, given battery and sampling factors, see ” Lithium and lead acid battery discharge time estimator.xlsx
This file also can be accessed using the USFWS electrofishing course resources link in the tools page of electrofishing.net
Safety features on equipment have been critical to providing safer working environments for crews. Equipment safety requirements is a topic that can be specific to the country or region, depending upon national codes. Features that are standard or desired include construction to electrical standards (wiring capacities, conductors in conduit, water-resistant plugs, etc.), an easily-accessible safety (on-off) switch (e.g., mushroom switch), a “power on” light, safety switch on hand-held electrode handle (backpacks), foot-activated switch on boats (pedal, mat, or kick-plate), tilt-switches on backpacks (forward, backward, and/or sideways), and railings on boat work decks. Additional features to consider include a backpack immersion switch (when operator goes down vertically into the water), anode out-of-water switch, battery compartment splash guard, and enunciator (“power on” sound for battery-powered models). Don’t forget the all-important personal protective gear as insulative gloves.
Particularly with backpacks, but also with generators used in shore-based or tow- barge shocking, weight is an important decision criterion. Backpacks vary in weight, due to the gear itself and the battery type and capacity. Batteries increase in weight with amp-hour capacity. So, there’s a tradeoff between battery discharge (shocking) time and weight. Lithium batteries, however, may weigh 60% less than comparable lead-acid batteries.
If weight is an important concern, one approach is to buy lower capacity (and weight) batteries, but buy more of them than you would higher capacity batteries. This probably would be a more expensive option but would logistically be fine if you can easily transport batteries near to your sampling sites.
ETS Electrofishing Systems, LLC
Madison, WI, USA.
- MBS Series boat control boxes
- ABP-3 backpack shocker
- SDC-1 Stream Barge Electrofishing System
Midwest Lake Electrofishing Systems
Polo, MO, USA.
- Infinity boat control box
- Infinity HC-80 boat control box
- Infinity Xstream Backpack Shocker
- MLES Infinity Stealth Min-boat Electrofisher (tow barge)
- MLES Infinity tow-barge Electrofishiner
Vancouver, WA, USA.
- Apex Electrofisher (backpack shocker)
- LR-24 Electrofisher (backpack shocker)
- VVP-15B boat control box
- PES Portable Electrosedation System
Aqua Shock Solutions
Pigeon Forge, TN, USA
- AS2 Backpack Shocker AC/DC
- AP1 Backpack Shocker Pulse DC
Other manufacturersExpand the list of manufacturers
- Halltech Aquatic Research Inc.http://www.halltechaquatic.com/ (Canada)
- Hans Grassl http://www.hans-grassl.com/ (Germany)
- Acuitec http://www.acuitec.es/ (Basque Country, Spain)
- EFKO http://www.efko-gmbh.de/ (Germany)
- Brettschneider http://www.electric-fishing.de/efgi1_e.html (Germany)
- Dream Electronique http://www.dream-electronique.com/ (France)
- Electracatch http://www.electracatch.com/ (Ireland)
- Niwa Instrument Systems http://www.niwa.cri.nz/rc/instrumentsystems/efish (New Zealand)
- Radomir Bednar http://www.r-bednar.cz/en/ (Czech Republic)
- Lug AB http://lugab.se/ (Sweden)
- Samus http://electro-fisher.com/ (Poland)
- Terik Technology AS http://www.terik.no/ (Norway)
- eFisherSuppy http://www.efishersupply.com (Oregon, U.S.A.) (for backpack batteries; ready-made)
- Ellis Battery http://www.ellisbatteries.com (Missouri, U.S.A.) (for backpack batteries; send pictures of requested battery for a price quote; if you have special connectors [as for the Smith-Root, Inc. batteries], send the old battery or the connectors, wires, handle, etc. to Ellis and they will build a new battery for you).
The following producers seem to have stopped their production.
- Biokon (http://www.biokon.se/) (Sweden)
- Paulsen (Norway)
- Fly Elektrofiskespesialisten (Norway)
- Faure Electronique (France)
- Deka-Gertebau (Germany)
- Brettschneider-Spezialelektronik (Germany)
- Marine Electrics Ltd. (Ireland)