Do intruding predators and trap position affect the reliability of catches in activity traps?

Johan Elmberg, Petri Nummi, Hannu Pöysä, Kjell Sjöberg

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)

Abstract

Forty lakes in Sweden and Finland were sampled in 1990 with activity traps to evaluate the effects of trapped predators on invertebrate catch. Vertebrate (fish, newts) and invertebrate (leeches, dragonflies, water beetles, backswimmers and water scorpions) predators were considered separately. Invertebrate predators affected neither the abundance nor the taxonomic diversity of the catches. Vertebrate predators had no effect on the abundance but reduced the taxonomic diversity of the catches significantly. Thus, vertebrate predators are a possible source of bias in activity trap catches, but oily concerning taxonomic diversity. Within the depth gradient studied (0.25-0.75 m), trap position (suspended in mid-water versus on the bottom) did not affect the percentages of nektonic and benthic invertebrates in the catches. The relative abundance of all taxa was similar in the catches from different trap positions, but the relative abundance of the most numerous taxa as well as the diversity of the catches differed between trap positions. We conclude that both mid-water and bottom traps are suitable for monitoring aquatic invertebrates, and that bottom traps may be preferred for practical reasons.

Original languageEnglish
Pages (from-to)187-193
Number of pages6
JournalHydrobiologia
Volume239
Issue number3
DOIs
Publication statusPublished - 1992
Externally publishedYes

Swedish Standard Keywords

  • Biological Sciences (106)

Keywords

  • ABUNDANCE
  • ACTIVITY TRAPS
  • DUCK FOOD
  • FOOD
  • HABITATS
  • LAKES
  • PREDATION
  • SIZE
  • SWEDEN
  • TRAP POSITION

Fingerprint

Dive into the research topics of 'Do intruding predators and trap position affect the reliability of catches in activity traps?'. Together they form a unique fingerprint.

Cite this