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The relative importance of lethal and non-lethal effects of fish on insect colonisation of ponds

Åbjörnsson, Kajsa LU ; Brönmark, Christer LU and Hansson, Lars-Anders LU (2002) In Freshwater Biology 47(8). p.1489-1495
Abstract
1. We hypothesised that adult insects actively monitor potential habitats for the presence of fish by means of chemical cues and avoid sites that pose significant risks. This was examined by quantifying colonisation of insects in outdoor pools with no fish (controls), fish (direct predation effect) or caged fish (chemical predator cues). 2. A significant direct effect of predation was found, but no indirect effect (avoidance of chemical cue pools), on the total biomass of colonising insects. However, predatory insects avoided fish-cue pools, thus releasing non-predatory insects from predation. This resulted in significantly greater biomass of non-predatory insects in fish-cue pools than control pools. 3. Fish reduced the number of species... (More)
1. We hypothesised that adult insects actively monitor potential habitats for the presence of fish by means of chemical cues and avoid sites that pose significant risks. This was examined by quantifying colonisation of insects in outdoor pools with no fish (controls), fish (direct predation effect) or caged fish (chemical predator cues). 2. A significant direct effect of predation was found, but no indirect effect (avoidance of chemical cue pools), on the total biomass of colonising insects. However, predatory insects avoided fish-cue pools, thus releasing non-predatory insects from predation. This resulted in significantly greater biomass of non-predatory insects in fish-cue pools than control pools. 3. Fish reduced the number of species of colonising insects in pools through predation. This negative influence of fish implies that caution is necessary when stocking wetlands and ponds with fish if the goal is to maximise biodiversity. 4. Our data suggest that although predatory aquatic insects may use chemical signals to assess the quality of potential habitats with respect to predation risk, direct predation is the main method by which fish affect insect assemblages in ponds. Because fish and invertebrate predators may both have strong effects on prey mortality, behavioural adjustment by insects to the actual predator regime within a habitat should be more important than avoiding colonisation of habitats with fish. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Freshwater Biology
volume
47
issue
8
pages
1489 - 1495
publisher
Wiley-Blackwell
external identifiers
  • wos:000177025900012
  • scopus:0036047763
ISSN
0046-5070
DOI
10.1046/j.1365-2427.2002.00883.x
language
English
LU publication?
yes
id
1a0c92fb-b27d-4889-9e5c-909f7cfb80e5 (old id 146590)
date added to LUP
2007-06-29 08:29:48
date last changed
2017-05-21 03:41:56
@article{1a0c92fb-b27d-4889-9e5c-909f7cfb80e5,
  abstract     = {1. We hypothesised that adult insects actively monitor potential habitats for the presence of fish by means of chemical cues and avoid sites that pose significant risks. This was examined by quantifying colonisation of insects in outdoor pools with no fish (controls), fish (direct predation effect) or caged fish (chemical predator cues). 2. A significant direct effect of predation was found, but no indirect effect (avoidance of chemical cue pools), on the total biomass of colonising insects. However, predatory insects avoided fish-cue pools, thus releasing non-predatory insects from predation. This resulted in significantly greater biomass of non-predatory insects in fish-cue pools than control pools. 3. Fish reduced the number of species of colonising insects in pools through predation. This negative influence of fish implies that caution is necessary when stocking wetlands and ponds with fish if the goal is to maximise biodiversity. 4. Our data suggest that although predatory aquatic insects may use chemical signals to assess the quality of potential habitats with respect to predation risk, direct predation is the main method by which fish affect insect assemblages in ponds. Because fish and invertebrate predators may both have strong effects on prey mortality, behavioural adjustment by insects to the actual predator regime within a habitat should be more important than avoiding colonisation of habitats with fish.},
  author       = {Åbjörnsson, Kajsa and Brönmark, Christer and Hansson, Lars-Anders},
  issn         = {0046-5070},
  language     = {eng},
  number       = {8},
  pages        = {1489--1495},
  publisher    = {Wiley-Blackwell},
  series       = {Freshwater Biology},
  title        = {The relative importance of lethal and non-lethal effects of fish on insect colonisation of ponds},
  url          = {http://dx.doi.org/10.1046/j.1365-2427.2002.00883.x},
  volume       = {47},
  year         = {2002},
}