A new method for reporting and interpreting textural composition of spawning gravel.

Fredrick B. Lotspeich; Fred H. Everest

doi:10.2737/PNW-RN-369

Treesearch

A new method for reporting and interpreting textural composition of spawning gravel.

Informally Refereed

Authors:

Fredrick B. Lotspeich, Fred H. Everest

Year:

1981

Type:

Research Note

Station:

Pacific Northwest Research Station

DOI:

https://doi.org/10.2737/PNW-RN-369

Source:

Res. Note PNW-RN-369. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 11 p

Download (PDF 275 KB)

Download (PDF 275 KB): https://research.fs.usda.gov/download/treesearch/7635.pdf

Abstract

A new method has been developed for collecting, sorting, and interpreting gravel quality. Samples are collected with a tri-tube freeze-core device and dry-sorted by using sieves based on the Wentworth scale. An index to the quality of gravel is obtained by dividing geometric mean particle size by the sorting coefficient (a measure of the distribution of grain sizes) of a sample. The resulting number is called the "fredle index" and is proposed as a standard for evaluating the reproductive potential of spawning gravel.

Keywords

Spawning beds, gravels, sediment sampling, stream habitat management, indexes (spawning gravel), fish habitat

Citation

Lotspeich, Fredrick B.; Everest, Fred H. 1981. A new method for reporting and interpreting textural composition of spawning gravel. Res. Note PNW-RN-369. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 11 p