Publication details
Srovnání metod pro odběr vzorků makrozoobentosu z nebroditelných toků
| Title in English | A comparison of sampling devices for macroinvertebrates in nonwadeable rivers |
|---|---|
| Authors | |
| Year of publication | 2012 |
| Type | Article in Periodical |
| Magazine / Source | Vodní hospodářství - příloha VTEI |
| MU Faculty or unit | |
| Citation | |
| Field | Ecology |
| Keywords | nonwadeable river; aquatic macroinvertebrates; air-lift sampler; van Veen grab; |
| Description | A comparison of two sampling devices (air-lift sampler and van Veen grab) for macroinvertebrates used in river sections deeper than 1 m was made at two nonwadeable rivers, the Labe and the Vltava. Both devices give approximately comparable results as regards metrics used in ecological status assessment (Si, PTI), nevertheless, the final classification of ecological status is sometimes better for grab samples. The results show that the air-lift collects higher number of individuals and taxa if compared to the grab, and is better able to characterize the assemblage of macroinvertebrates living in nonwadeable parts of the riverbed at a sampling site. Ten subsamples taken by the air-lift contained almost 80 % of the site assemblage recorded using both devices (exactly 78,4 %), whereas ten subsamples taken by the grab contained only 70,8 % species. According to literature, it is sufficient to collect 80 % of the assemblage species spectrum for the purposes of biomonitoring. To collect sufficient number of taxa, the suction duration of a single subsample should range between 20 and 30 seconds, except at sites with very fine substrate, where the net is full earlier. Although the air-lift is more effective, for a comprehensive characterization of nonwadeable habitats it is necessary to use also the grab which collected additional 20 % of taxa (the air-lift collected 30 % of taxa, which were not collected by the grab). |