Fish Sampling Techniques

Target Audience:

Fish biologists in federal, state, and tribal agencies, university students.

Summary and Objectives:

The usefulness of data for informing population or trend assessment is dependent on the choice of gear and deployment strategies. The ability to integrate gear design, materials, and operation, fish species behavior, and habitat conditions for effective sampling requires a substantial level of expertise. Making informed purchasing decisions and modifying a gear for the purpose of specific species is a first order capability. Participants will learn to properly choose, deploy, maintain, and purchase passive and active capture gears, including nets, traps, seines, trawls, and electrofishing units. Safe operating procedures will be addressed throughout. Depending upon the location, habitats sampled will include big rivers (or reservoirs) and smaller streams. This is a field-based course.

Upon completion of this course, participants will be able to:

• Select gear types for different habitat types, target species and size ranges.
• Gain basic knowledge of how gear fishes within different aquatic environments.
• Apply knowledge of important criteria, design, materials, and terms to purchase gear from a net or electrofishing vendor.
• Distinguish between designs of effective and suboptimal gear: fyke nets, gill nets, trammel nets, purse, beach, and blocking seines, etc.
• Evaluate gear for quality of materials and construction.
• Customize gear for improved fishability.
• Conduct basic set-up on boats for seining, trawling, and electrofishing: what to do and not to do.
• Properly deploy or operate various gear types in different habitat types and assess performance.
• Remove fish from entanglement gear and properly collect fish during electrofishing.
• Follow safe boat operation while sampling, particularly in flowing water.
• Identify and fix problems (troubleshooting).
• Properly mend, splice, tie knots, and repair net and trap gear.
• Properly maintain and store gear.
• Implement electrofishing standardization protocols.

Competencies Addressed: 

Aquatic Ecology - Basic, Fishery Biology - Intermediate, Wildlife and Fisheries Biology Management - Intermediate, Field Data Collection - Intermediate