Fish population studies have been a major component of ORSANCO monitoring activities throughout the history of the organization. In 1957, routine lockchamber surveys were initiated in cooperation with state and federal environmental and fisheries agencies. The methods employed, size and structure of the lockchambers, and locations of the sampling have remained relatively unchanged throughout this 40+ year period. The data collected from these surveys comprise one of the largest, most comprehensive river fisheries databases in existence.

In 1990, ORSANCO added nighttime electrofishing to supplement lockchamber studies. Lockchamber sampling, while useful for providing valuable information, is very restrictive: Only 20 lock and dam facilities are located on the Ohio River for sampling. Because of this limitation, electrofishing has now become the primary means utilized by ORSANCO to study fish populations in the Ohio River.

Employing the electrofishing method, ORSANCO focused efforts on the collection of data for the development of biological criteria, or biocriteria, for the Ohio, conducting intensive surveys in 11 of the 20 pools.

For more information about ORSANCO's Fish Population Studies, contact: ORSANCO Public Information Department or Erich Emery