USGS-NAWQA: NAWQA Fish 2002 (Wade):  Fish Sample Collection in Wadeable Streams by Electrofishing and Seine

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program
Current Revision
2002-Supersedes USGS Open-File Report 93-104 (fish) and USGS WRIR 98-4239 (fish)
Biological  (Waterbody type - Wadeable stream)
Electrofishing Unit
Method Subcategory
Method Source
  Moulton, S.R., II, Kennen, J.G., Goldstein, R.M. and Hambrook, J.A., 2002, Revised protocols for sampling algal, invertebrate, and fish communities as part of the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 02-150, 75 p.
USGS NAWQA 2002 Eco Protocols - Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program
Brief Method Summary
The fish sampling protocols described in this report present methods for collecting a representative sample of the fish community from the stream. Such a sample contains most, if not all, species in the stream at the time of sampling in numbers proportional to their actual abundance. The reach is the representative portion of the stream that is sampled. Each reach contains various instream habitats consisting of different geomorphic channel units, substrates, and hydrologic conditions. Fish species are distributed in the stream reach according to these instream habitats. No single fish collection gear or method is adequate to sample the diversity of habitats found in the reach. Therefore, two complementary methods are used for collecting fish: electrofishing and seining. Electrofishing is done in two separate passes of the reach; the fish collected from the first pass are processed before the second pass is conducted. Seining is done after electrofishing. Three seine collections (hauls or kicks) are taken and combined before processing fish. The fish sampling protocols present techniques for applying these sampling methods and procedures for processing fish specimens in the field to determine total length, weight, and external anomalies. These revised fish sampling protocols are based on the original guidance presented by Meador and others (1993) and the QA protocols by Walsh and Meador (1998).
Scope and Application
This method describes the USGS National Water-Quality Assessment Program (NAWQA) protocol for sampling fish community of a stream (FISH). It is one protocol of the larger USGS Open-File Report 02-150. Fish sampling protocols are described in section 6 of the report. The protocol describes techniques to be used for NAWQA sampling teams to determine fish community composition of both wadeable and nonwadeable streams. Techniques for a combination of electrofishing and seining are described. The full report summarizes the protocols report provides revised protocols for sampling algal, invertebrate, and fish communities as part of the NAWQA Program. The protocols describe required methods for collecting and processing biological samples. This report revises the original NAWQA protocols for algae (Porter and others, 1993), invertebrates (Cuffney and others, 1993), and fish (Meador and others, 1993; Walsh and Meador, 1998).
Applicable Concentration Range
Although electrofishing and seining represent the standard methods for collecting a representative fish community sample from a reach, there may be occasions when these methods cannot be used effectively. For example, electrofishing is ineffective when specific conductivity is < 20 ┬ÁS/cm. Likewise, seining is hampered when a large number of woody snags and other types of irregular debris are present in the reach that would prevent maintaining the lead line on the stream bottom. When physical conditions in the reach prohibit the use of these standard methods, alternative sampling methods (for example, hoop netting, minnow traps) may be proposed. However, proposed alternative sampling methods must be discussed with the study team leader and regional biologist on an individual basis to ensure appropriate application and compliance with State regulations regarding their use.
Quality Control Requirements
Specimens that are not positively identified in the field are preserved, labeled, and returned to the laboratory for later identification. Some identifiable specimens also might be preserved and deposited in a voucher collection. A confirmation report is requested for all fish that are deposited in a voucher collection.
Sample Handling
The goal of processing collections of fish in the field is to collect information on taxonomic identification, length, weight, abundance, and the presence of external anomalies (fig. 11) with minimal harm to specimens that will be released alive back into the stream. The major steps in processing collections of fish from each electrofishing pass and group of seine hauls or kicks include the following: 1. Sort fish into identifiable and unidentifiable groups. Process threatened and endangered (T&E) fish species first before other identifiable species. Preserve unidentifiable species and return them to the field office for identification. 2. Hold and anesthetize fish in a manner consistent with minimizing stress or death. 3. Identify and enumerate each identifiable species. 4. Measure total length and weigh at least 30 specimens of each species (excluding T&E species). 5. Examine up to 30 specimens of each species (excluding T&E species) for external anomalies. 6. Record data on the Fish Field Data Sheet. 7. Preserve selected specimens for identification in the laboratory or vouchering; release all other specimens alive back into the stream. After examination, fish are placed in a container of ambient stream water and allowed to recover from the anesthetic before being released back into the stream. Fish should be released downstream of the sampling reach to minimize the potential for re-sampling and sample bias.
Maximum Holding Time
All captured fish, excluding T&E species, are placed in a live cage or boat live well for subsequent processing and an effort is made to minimize stress or death to specimens. T&E species are identified, enumerated, and released immediately to the stream.
Relative Cost
Sample Preparation Methods
Only a few fish should be anesthetized at a time to minimize potential mortality from sedation.