Dukerschein, J. T., Gent, R., and Sauer, J., 1996, Recovery of macroinvertebrates
by screening in the field: A comparison between coarse (1.18 mm)- and fine (0.60
mm)-mesh sieves: Journal of Freshwater Ecology, v. 11, no. 1, p. 61–65.

Abstract

We evaluated the potential loss of target benthic macroinvertebrates from
coarse-mesh field wash down of samples through a 1.18-mm mesh sieve nested on a
0.60-mm mesh sieve. Visible target organisms (midges, mayflies, and fingernail
clams) in the 1.18-mm mesh sieve were removed from the sample and enumerated
in the field. The entire contents of both sieves were preserved for subsequent
laboratory enumeration under 4X magnification. Percent recoveries from each
treatment were based on total intact organisms found in all sieves. Percent recovery
for fingernail clams found in the field (31%) was lower than for mayflies (79%) and
midges (88%). Laboratory enumeration of organisms retained by the 1.18-mm sieve
yielded additional fingernail clams (to total 74% recovered in the field and lab),
mayflies (to total 89%), and midges (to total 91%). If the 1.18-mm sieve is used
alone in the field, it is adequate to monitor mayflies, midges >1 cm, and adult
fingernail clams greater than or equal to 5.0 mm shell length.

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