Sometimes, things just don’t work as expected. You go to a new sampling site, determine ambient water conductivity, estimate a good starting point for standardizing by power and conduct a quick pretrial to fine tune the voltage, current or power levels for successful fishing. But, either the starting point is incorrect, or the sampling begins successfully and then something changes to reduce effectiveness. Below are three examples of unusual circumstances in electrofishing. Two of these were my direct experiences; the other was reported to me.Continue Reading..
Jim Reynolds and I just taught a boat electrofishing course in Redding, California at Whiskeytown Lake. That provided some threshold fishing data for voltage, current and power for each of four electrofishing boats. One can standardize by power using any of the three parameters. Which parameter is less variable among a fleet of boats?
Fisheries biologists are knowledgeable about fish, their habitat and about ways to collect fish using a variety of gear and techniques. Many are less familiar with the electrical terms which are used in fish capture using electricity. This blog is meant to explain electrical terms which are used in electrofishing classes and in the literature.
Electrical fields around electrofishing anodes are critical to fish capture effectiveness. The size, shape and intensity of those electrical fields are determined by the anode design and deployment in the water as well as by the electricity applied to them. There were two main questions to answer in this little study: (1) Could accurate electrical measurements be made from approximately ¼ scale model electrodes in a small body of water, and (2) Would those measurements provide useful information about the effect of anode ring size on their electrical fields?