Electrofishing is an active sampling method for obtaining a qualitative and quantitative sample of fish populations using electricity. An electrofishing sampling crew consists of two netters and a driver. The crew conducts electrofishing at night because of the increased foraging that occurs along the shoreline in the evening hours. An electrical current is placed in the water, momentarily stunning fish. As the driver maneuvers the boat through the electrofishing zone, netters remove the stunned fish from the water. The fish are then placed into the live well for data collection. Finally, the fish are returned to the water unharmed.

In 1993 the Commission began an intensive survey approach to collecting electrofishing data on the Ohio River. As of 2000, eleven Ohio River pools have been surveyed. These pools include: Montgomery, Hannibal, Greenup, McAlpine, Newburgh, Smithland and Pools 52 and 53.

Field Methods

• Site Selection
  Sampling zones are selected along the shoreline with the most diverse macrohabitat features within the designated sampling area.
• Zone Measurement
  Electrofishing zones are 500 meters in length. The boundaries of each electrofishing zone are clearly marked on a stationary object with fluorescent orange paint and/or orange surveyor's flagging.
• Site Indexing
  The location of each sample zone is indexed by river mile. A Global Positioning System (GPS) will be utilized to obtain long/lat coordinates. These coordinates will be used in designating each zone in ORSANCO's Geographic Information System (GIS). The coordinates should be taken at the upstream boundary, midpoint, and downstream boundary of the zone.
• Water Chemistry Parameters
  Dissolved oxygen, conductivity, temperature, pH, and secchi depth are recorded at the upstream end of each electrofishing zone immediately prior to sampling. River stage and general weather conditions are recorded at this time.
  

Data Handling and Analysis
Field data sheets are collected at the conclusion of each study by the Principal Investigator. Upon return to the office, copies are produced and forwarded to participating state agency personnel upon request. ORSANCO staff compiles and reviews the data prior to entry into the ORSANCO data base.

Fish Disposal Procedures
All living specimens, except voucher and questionable specimens, are returned to the water.

For more information about ORSANCO's Electrofishing Studies, contact:
Erich Emery or Matt Wooten