Nets recommended in this manual
Kick net
For rocky-bottom stream sampling, a kick net of 590 µm (a #30 mesh size) or 500 µm (#35 mesh size) is recommended. (Mesh size is usually measured in microns, µm. The higher the number, the coarser the mesh.)
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D-frame net
For muddy-bottom stream sampling, a long-handled D-frame or dip net is recommended for reaching into vegetation that grows along stream banks or is attached to the stream bottom, and for sweeping up macroinvertebrates dislodged from woody debris. D-frame
nets also come in different mesh sizes.
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This manual recommends that volunteer programs purchase their macroinvertebrate sampling nets from scientific supply houses to ensure a standard degree of net quality and known mesh size. Some supply houses might sell the components of the net separately.
Volunteer programs then buy the net material commercially, supply their own handles, and build the nets using volunteer labor.
Many programs use coarser mesh than is recommended in this manual. Coarser mesh is generally less expensive. However, smaller organisms can be lost throguh the mesh during sampling. If you are in doubt as to what mesh size to use, consult your technical a
dvisor. If possible--and especially if you want your volunteer data to be used by state and local water managers--it is best to use nets of the same type and size as those which water quality professionals use in your state.
Other types of commonly used nets
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Metal frame net
Used by the River Watch Network for sampling both rocky-bottom and muddy-bottom streams.
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Surber Sampler
Used by professional monitoring programs, this sampler delineates an exact stream bottom area to be disturbed.
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Figure 4.7
Examples of macroinvertebrates sampling nets
Nets used by professionals and volunteers vary in overall size, design, and mesh size. |
