Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling
Because of its complex life cycle, cryptic behavior, body shape, ability to excrete mucus and excellent maneuvering, the European eel (Anguilla anguilla) is difficult to monitor. During many years of gillnetting in Dutch and Czech freshwaters, we registered characteristic involutions of gillnet nett...
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Online Access: | https://doi.org/10.1016/j.limno.2012.09.003 http://hdl.handle.net/11104/0221753 |
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ftczacademyscien:oai:asep.lib.cas.cz:CavUnEpca/0392323 2024-02-04T09:52:57+01:00 Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling Prchalová, M. (Marie) Kubečka, J. (Jan) Říha, M. (Milan) Čech, M. (Martin) Jůza, T. (Tomáš) Ketelaars, H. A. M. Kratochvíl, M. (Michal) Mrkvička, T. (Tomáš) Peterka, J. (Jiří) Vašek, M. (Mojmír) Wagenvoort, A. J. 2013 https://doi.org/10.1016/j.limno.2012.09.003 http://hdl.handle.net/11104/0221753 eng eng doi:10.1016/j.limno.2012.09.003 urn:pissn: 0075-9511 urn:eissn: 1873-5851 http://hdl.handle.net/11104/0221753 beach seine trawl fish-monitoring technique species selectivity feeding strategy spatial distribution info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2013 ftczacademyscien https://doi.org/10.1016/j.limno.2012.09.003 2024-01-09T17:24:20Z Because of its complex life cycle, cryptic behavior, body shape, ability to excrete mucus and excellent maneuvering, the European eel (Anguilla anguilla) is difficult to monitor. During many years of gillnetting in Dutch and Czech freshwaters, we registered characteristic involutions of gillnet netting with a partially eaten fish inside. We concluded that these involutions were the result of eels attacking fish caught in gillnets and called the occurrences eel attacks. When we compared the abundance of eel attacks in gillnets with the abundances of eels recorded using active gears (beach seining and trawling), we found a positive and significant correlation (partial Spearman R = 0.640) that can be used for rough eel-abundance assessment. The most frequently attacked fishes were young individuals of abundant species (Perca fluviatilis, Sander lucioperca, Rutilus rutilus and Osmerus eperlanus) and small species (Gymnocephalus cernua) up to 100 mm standard length. The eels preferred pikeperch and avoided roach and smelt. The reason for prey species preferences was most likely prey species distribution rather than size selectivity. The eels attacked fishes in gillnets during the night, most likely after midnight. The eel attacks were not distributed homogenously among the studied reservoirs, geographical areas and years. The frequency of eel attacks was higher in benthic than in pelagic habitats. Eel attacks were more frequent in Dutch than in Czech reservoirs, corresponding to a general decline of eel densities with increasing distance from the sea. The number of eel attacks also declined significantly from 1998 to 2008. The present study showed that eel attacks can be successfully used as a new, simple and nonintrusive tool for monitoring eel abundance using gillnets. Gillnets are widely used in fish monitoring, and hence, gillnet sampling performed throughout Europe has a great potential for eel-abundance assessment. Article in Journal/Newspaper Anguilla anguilla European eel The Czech Academy of Sciences: Publication Activity (ASEP) Limnologica 43 3 194 202 |
institution |
Open Polar |
collection |
The Czech Academy of Sciences: Publication Activity (ASEP) |
op_collection_id |
ftczacademyscien |
language |
English |
topic |
beach seine trawl fish-monitoring technique species selectivity feeding strategy spatial distribution |
spellingShingle |
beach seine trawl fish-monitoring technique species selectivity feeding strategy spatial distribution Prchalová, M. (Marie) Kubečka, J. (Jan) Říha, M. (Milan) Čech, M. (Martin) Jůza, T. (Tomáš) Ketelaars, H. A. M. Kratochvíl, M. (Michal) Mrkvička, T. (Tomáš) Peterka, J. (Jiří) Vašek, M. (Mojmír) Wagenvoort, A. J. Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
topic_facet |
beach seine trawl fish-monitoring technique species selectivity feeding strategy spatial distribution |
description |
Because of its complex life cycle, cryptic behavior, body shape, ability to excrete mucus and excellent maneuvering, the European eel (Anguilla anguilla) is difficult to monitor. During many years of gillnetting in Dutch and Czech freshwaters, we registered characteristic involutions of gillnet netting with a partially eaten fish inside. We concluded that these involutions were the result of eels attacking fish caught in gillnets and called the occurrences eel attacks. When we compared the abundance of eel attacks in gillnets with the abundances of eels recorded using active gears (beach seining and trawling), we found a positive and significant correlation (partial Spearman R = 0.640) that can be used for rough eel-abundance assessment. The most frequently attacked fishes were young individuals of abundant species (Perca fluviatilis, Sander lucioperca, Rutilus rutilus and Osmerus eperlanus) and small species (Gymnocephalus cernua) up to 100 mm standard length. The eels preferred pikeperch and avoided roach and smelt. The reason for prey species preferences was most likely prey species distribution rather than size selectivity. The eels attacked fishes in gillnets during the night, most likely after midnight. The eel attacks were not distributed homogenously among the studied reservoirs, geographical areas and years. The frequency of eel attacks was higher in benthic than in pelagic habitats. Eel attacks were more frequent in Dutch than in Czech reservoirs, corresponding to a general decline of eel densities with increasing distance from the sea. The number of eel attacks also declined significantly from 1998 to 2008. The present study showed that eel attacks can be successfully used as a new, simple and nonintrusive tool for monitoring eel abundance using gillnets. Gillnets are widely used in fish monitoring, and hence, gillnet sampling performed throughout Europe has a great potential for eel-abundance assessment. |
format |
Article in Journal/Newspaper |
author |
Prchalová, M. (Marie) Kubečka, J. (Jan) Říha, M. (Milan) Čech, M. (Martin) Jůza, T. (Tomáš) Ketelaars, H. A. M. Kratochvíl, M. (Michal) Mrkvička, T. (Tomáš) Peterka, J. (Jiří) Vašek, M. (Mojmír) Wagenvoort, A. J. |
author_facet |
Prchalová, M. (Marie) Kubečka, J. (Jan) Říha, M. (Milan) Čech, M. (Martin) Jůza, T. (Tomáš) Ketelaars, H. A. M. Kratochvíl, M. (Michal) Mrkvička, T. (Tomáš) Peterka, J. (Jiří) Vašek, M. (Mojmír) Wagenvoort, A. J. |
author_sort |
Prchalová, M. (Marie) |
title |
Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
title_short |
Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
title_full |
Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
title_fullStr |
Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
title_full_unstemmed |
Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling |
title_sort |
eel attacks – a new tool for assessing european eel (anguilla anguilla) abundance and distribution patterns with gillnet sampling |
publishDate |
2013 |
url |
https://doi.org/10.1016/j.limno.2012.09.003 http://hdl.handle.net/11104/0221753 |
genre |
Anguilla anguilla European eel |
genre_facet |
Anguilla anguilla European eel |
op_relation |
doi:10.1016/j.limno.2012.09.003 urn:pissn: 0075-9511 urn:eissn: 1873-5851 http://hdl.handle.net/11104/0221753 |
op_doi |
https://doi.org/10.1016/j.limno.2012.09.003 |
container_title |
Limnologica |
container_volume |
43 |
container_issue |
3 |
container_start_page |
194 |
op_container_end_page |
202 |
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1789962667782307840 |