Sampling Benthos and Substrate Materials, Down to 50 microns in Size, in Shallow Streams

Abstract

Stream bed materials, both biotic and abiotic, in the size range 50 μ–ca. 200 mm can be sampled unselectively, in shallow streams, with a simple inexpensive apparatus consisting of a box provided with an adjustable upstream inlet, and, downstream, two nets, one within the other. Collected materials are wet-sieved and the volumes of inorganic material passed by successively finer sieves are plotted as cumulative curves against a logarithmic size scale. Curves are given for materials from three contrasting habitats: a riffle, and pool, of a coastal stream, and an artificial spawning channel. Examples are also given of the densities, size distribution, and vertical stratification of invertebrates from these habitats. Applications of the method to studies on fish biology, invertebrate ecology, and geomorphology are indicated.

Comparison of Samples of Stream Bottom Fauna Collected During the Day and at Night1

“…The lower part of the downstream side also had a 30 x 30 cm opening to which was attached a net having a 320-p pore size. A 320-p mesh, although quite fine, does not retain small chironomid and simuliid larvae ( Mundie 1971). The net was attached to the frame with wingnuts and could be detached before removing the animals.…”

Impact of mild experimental acidification on short term invertebrate drift in a sensitive British Columbia stream

“…Quantitative corrections for differential laboratory losses among taxonomic categories during the sieving process (Mundie, 1971) could not be made because of the large amount of obscuring organic matter. Based on a laborious analysis of one sample, losses among the various taxonomic categories ranged from 0 to > 80%.…”

Further studies on the distribution of stream animals within the substratum1

“…However, cvcn after 6 months thcrc were still apprcciablc numbers of animals down to 40 cm. Mundie ( 1971)) using an apparatus that did not involve colonization of gravel that had been moved, also rcportcd signifi-L This work was supported by a grant from the National Research Council of Canada.…”