USGS-NAWQA: NAWQA Invert RTH 2002 (Wade): Invertebrate Sample Collection at Richest Targeted Habitat (RTH) in wadeable streams by Slack sampler
|
Official Method Name
|
Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program |
|---|---|
|
Current Revision
| 2002 |
|
Media
|
WATER (Waterbody type - Wadeable stream) |
|
Instrumentation
|
Invertebrate Net (w/ handle) |
|
Method Subcategory
|
Population/Community |
|
Method Source
|
|
|
Citation
|
|
|
Protocol
|
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
|
This is one of two types of instream invertebrate samples collected in the NAWQA Program. The Invertebrate Richest Targeted Habitat (IRTH) sample is a semi-quantitative sample that is collected to provide a measure of relative abundance of the invertebrate taxa living in the RTH in the reach. The semi-quantitative IRTH sample consists of a series of discrete collections (for example, five Slack samples or 10 woody snag sections) that are processed and combined into a single composited sample. Sampling begins by identifying and documenting the types of instream habitats present in the reach. This information is then used to determine where sampling is conducted in the stream reach. Samples are collected using a Slack sampler (modified Surber sampler; 500um screen) in riffles and woody snags for the RTH samples. Fine grained sediments are typically sampled using a grab sampler (500um screening). Final samples are composites of subsamples collected from different locations within the stream reach or riffle. Samples are preserved (10% formalin) in the field for transport. |
|
Scope and Application
|
This method describes the USGS National Water-Quality Assessment Program (NAWQA) protocol for invertebrate sampling, specifically Invertebrate Targeted Habitat (IRTH). It is one protocol of the larger USGS Open-File Report 02-150. Invertebrate sampling protocols are described in section 5 of the report. The RTH sample prioritizes riffles as the preferred habitat. When riffles are not present, samples are collected from woody debris. The USGS OFR 02-150 report summarizes the protocols report provides 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
|
|
|
Interferences
|
None provided |
|
Quality Control Requirements
|
Remove large debris and organisms. Sieve discrete sample. Reduce volume. Preserve with 10% buffered formalin. Elutriates, if done, are lab processed. All identifications done by qualified experts at certified lab. |
|
Sample Handling
|
- Field splits conducted when sample volume is >0.75 L. - Field processing can result in 4 sample components: large-rare, main-body, elutriate, and split-sample. - Samples are split until composite volume is LTE 0.75 L. - Preserve in 10% buffered formalin; tightly sealed in dark at room temperature with sample label. |
|
Maximum Holding Time
|
Indefinite with proper preservation. |
|
Relative Cost
|
3 - 6 hrs. per site/sample |
|
Sample Preparation Methods
|
Remove large debris from each discrete collection and inspect for attached invertebrates. |
