Identifying electrofishing capture-prone response thresholds for catfish and smallmouth bass in Missouri

Objectives

1. Determine the effective conductivity of live SMB, BLC and FHC based on the behavioral response to electrofishing.
2. Develop species-specific standardized electrofishing output goals to achieve constant power transfer to fish across a range of water conductivities and water temperatures.
3. Evaluate these output goals in the field and develop power output tables for each species that can be referenced by field staff to standardize electrofishing output across water temperatures and water conductivity levels.

Overview

Standardization of electrofishing output will minimize bias, reduce variation in catch, and allow for more valid spatial and temporal comparisons of sample data, regardless of the electrofishing control box used.  Biologists need to know how conductivity of the water relates to the effective conductivity of Smallmouth Bass (SMB), Blue Catfish (BLC) and Flathead Catfish (FHC), hereafter referred to individually by the abbreviations or collectively as bass and catfish, in order to develop standardized electrofishing output goals that are species specific and maintain a desired capture-prone fish response (e.g., taxis or immobilization) across a range of water conductivities, water temperatures, and fish sizes.  The effective power (the product of current and voltage) transferred from the water to the fish during electrofishing is a critical electrical factor affecting fish response; power transfer depends on the ratio of fish conductivity to water conductivity.  Knowing the effective fish conductivity of a particular species would allow researchers to develop applied power, voltage, and amperage goal tables, standardized by power, for use by biologists when sampling targeted species.  Standardizing electrofishing output by power would improve Missouri Department of Conservation’s ability to more accurately assess and monitor bass and catfish populations.

Acknowlegements

  • Investigator: Zach Morris, M.S. student
  • Project Supervisors: Dr. Craig Paukert
  • Funding: Missouri Department of Conservation (MDC)
  • Cooperators: Zach Ford, Andy Turner: MDC
  • Location: Missouri
  • Expected Date of Completion: June 2020