A new benthos dredge ("Triple-D") for quantitative sampling of infauna species of low abundance
Bergman, M.J.N.; van Santbrink, J.W. (1994). A new benthos dredge ("Triple-D") for quantitative sampling of infauna species of low abundance. BEON Rapport = BEON-report, 13. Programma Bureau BEON: Den Haag. 61-75 pp.
Part of: BEON Rapport = BEON-report. Programma Bureau BEON: Den Haag. ISSN 0924-6576, more
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| Authors | | Top |
- Bergman, M.J.N.
- van Santbrink, J.W.
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| Abstract |
Grabs and cores are commonly used to estimate densities of infauna species quantitatively. However, because of the limited sample size, these equipments are not practicable for sampling species of low abundance. With trawls and dredges samples of much larger sizes can be obtained, but the existing types of gear are, at best, semi-quantitative for catching infauna. In this paper a prototype dredge is introduced for quantitative sampling larger-sized (>10mm) infauna of low abundance. This "Deep Digging Dredge" (Triple-D) is rigged with an interchangeable blade to collect a strip of the seabed. During the haul, several hundred meters long, the excavated sediment is sieved through a net with a 1.4 cm stretched mesh size. The prototype was sucessfully tested on infauna in fine-grained adhesive sediments in the Wadden Sea, using a 20cm wide blade with a penetration depth into the sediment of 10cm. In field studies on soft and sandy bottoms in the North Sea, the Triple-D estimated the densities of some epifauna and flatfish species higher than a fine meshed beamtrawl. |
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