1. Electrofishing Basics Electrofishing is the process of passing electric current through freshwater, which stuns fish and causes them to rise to the surface where they can be caught with a net This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License

2. Electrofishing Electrofishing usually requires a team of two or more people, one controlling the anode that delivers the electric current, others working with hand nets and possibly others collecting fish from a barrier net downstream

3. Electrofishing The anode, which is the source of the electric current, is operated by one person. They place the anode in the water and downstream a second person uses a hand net to catch the stunned fish AnodeHand net

4. Electrofishing A barrier net is used to catch any fish that are missed by the hand net. The barrier net is placed immediately down stream of where the electrofishing is taking place

5. Electrofishing In saltwater, fish are less conductive than the surrounding water so the electric current passes through the water not the fishes body and electrofishing therefore doesn’t work in salt water. Any fish close to the anode are briefly stunned making them easy to see and catch. Electrofishing works on freshwater fish because they are more conductive than the surrounding water so the electric current preferentially passes through their bodies.

6. Electrofishing A source of electricity is essential for electrofishing. This slide illustrates the use of a small land based generator carried in a vehicle. Generators provide high power but are relatively difficult to transport and so are unsuitable for conditions where access is difficult

7. Electrofishing This slide illustrates a portable electrofishing backpack, which uses a battery to provide the electric current. Although heavy, such backpack systems allow electrofishing to be carried out in a much wider range of situations than would be possible with a generator powered system. The disadvantages are less power and the need to recharged regularly

8. Electrofishing The type of current (alternating or direct) and if direct whether it is delivered in a pulsed or smooth mode and the voltage can all be adjusted depending on local conditions (such as water conductivity) and the target species. For more information, the Fisheries Co-ordination Centre at Barony College, Inverness provide a very useful Introductory Electrofishing Training Manual Which can be viewed at http://www.sfcc.co.uk/pdfs/SFCC%20Introductory%20Electrofishing%20Training%20Manual %20(Level%20II)%20(1).pdfhttp://www.sfcc.co.uk/pdfs/SFCC%20Introductory%20Electrofishi ng%20Training%20Manual%20(Level%20II)%20(1).pdf http://www.sfcc.co.uk/pdfs/SFCC%20Introductory%20Electrofishing%20Training%20Manual %20(Level%20II)%20(1).pdfhttp://www.sfcc.co.uk/pdfs/SFCC%20Introductory%20Electrofishi ng%20Training%20Manual%20(Level%20II)%20(1).pdf

9. Attribution This presentation has been prepared by Ross MacLeod, Division of Ecology & Evolutionary Biology, University of Glasgow and is based on the University of Glasgow’s Freshwater and Terrestrial Ecology Field Courses at the Scottish Centre for Ecology and the Natural Environment, Loch Lomond, ScotlandRoss MacLeod The presentation and the photos within it have been released as an Open Educational Resources under a Creative Commons Attribution- NonCommercial-ShareAlike 2.5 License as part of a UK Centre of Bioscience Open Educational Resources project http://www.bioscience.heacademy.ac.uk/resources/oer/ http://www.bioscience.heacademy.ac.uk/resources/oer/ For more information and any feed back please contact UK Centre of Bioscience or Ross MacLeodUK Centre of Bioscience Ross MacLeod