Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream

In recent decades, the population of European eel Anguilla anguilla has strongly declined and the stock is outside safe biological limits. Freshwater habitat degradation has been cited as a key causal factor in the European eel decline, but there are limited studies assessing the responses of this s...

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Main Authors: Champkin James D., Bašić Tea, Haubrock Phillip J., Balzani Paride, Sayer Carl D., George Laura K., Godard Michael J., Vilizzi Lorenzo, Copp Gordon H.
Format: Article
Language:English
Published: EDP Sciences 2024-01-01
Series:Knowledge and Management of Aquatic Ecosystems
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Online Access:https://www.kmae-journal.org/articles/kmae/full_html/2024/01/kmae240069/kmae240069.html
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author Champkin James D.
Bašić Tea
Haubrock Phillip J.
Balzani Paride
Sayer Carl D.
George Laura K.
Godard Michael J.
Vilizzi Lorenzo
Copp Gordon H.
author_facet Champkin James D.
Bašić Tea
Haubrock Phillip J.
Balzani Paride
Sayer Carl D.
George Laura K.
Godard Michael J.
Vilizzi Lorenzo
Copp Gordon H.
author_sort Champkin James D.
collection DOAJ
description In recent decades, the population of European eel Anguilla anguilla has strongly declined and the stock is outside safe biological limits. Freshwater habitat degradation has been cited as a key causal factor in the European eel decline, but there are limited studies assessing the responses of this species to river habitat restoration efforts. This study utilized mark-and-recapture data from annual electrofishing surveys conducted between 2009 and 2014 to describe European eel population density and size structure (length, weight) in the River Glaven − a chalk stream in eastern England. Short-term effects of river restoration on European eel were assessed via a Before-After-Control-Impact experimental design. Of the recaptured individuals, 73% were sedentary and the rest mobile. Despite re-meandering work increasing habitat heterogeneity in the restoration reach relative to the control reach, no change in European eel density or size structure was detected across treatments and time. While length and weight increased in the downstream control reach over the study period, density declined. This can be attributed to various local stressors such as barriers to European eel migration, as well as broader range-scale causes including climatic and oceanic factors. Although further research is ideally necessary to ensure adequate sample sizes, as well as to provide long-term monitoring of eel responses to river restoration, this study emphasizes the need for whole-catchment efforts in European eel conservation that combine river–floodplain restoration with greatly improved fish passage.
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spelling doaj-art-87d81e4a276244b7b01924c8916eee4c2025-01-08T11:01:17ZengEDP SciencesKnowledge and Management of Aquatic Ecosystems1961-95022024-01-0104252310.1051/kmae/2024021kmae240069Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk streamChampkin James D.0Bašić Tea1https://orcid.org/0000-0001-8761-5750Haubrock Phillip J.2Balzani Paride3Sayer Carl D.4George Laura K.5Godard Michael J.6Vilizzi Lorenzo7https://orcid.org/0000-0001-8103-885XCopp Gordon H.8The Angling Trust and Fish Legal, Eastwood HouseCentre for Environment, Fisheries and Aquaculture ScienceDepartment of River Ecology and Conservation, Senckenberg Research Institute and Natural History Museum FrankfurtFaculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České BudějoviceDepartment of Geography, University College LondonDepartment of Geography, University College LondonCentre for Environment, Fisheries and Aquaculture ScienceFaculty of Biology and Environmental Protection, Department of Ecology and Vertebrate Zoology, University of LodzCentre for Environment, Fisheries and Aquaculture ScienceIn recent decades, the population of European eel Anguilla anguilla has strongly declined and the stock is outside safe biological limits. Freshwater habitat degradation has been cited as a key causal factor in the European eel decline, but there are limited studies assessing the responses of this species to river habitat restoration efforts. This study utilized mark-and-recapture data from annual electrofishing surveys conducted between 2009 and 2014 to describe European eel population density and size structure (length, weight) in the River Glaven − a chalk stream in eastern England. Short-term effects of river restoration on European eel were assessed via a Before-After-Control-Impact experimental design. Of the recaptured individuals, 73% were sedentary and the rest mobile. Despite re-meandering work increasing habitat heterogeneity in the restoration reach relative to the control reach, no change in European eel density or size structure was detected across treatments and time. While length and weight increased in the downstream control reach over the study period, density declined. This can be attributed to various local stressors such as barriers to European eel migration, as well as broader range-scale causes including climatic and oceanic factors. Although further research is ideally necessary to ensure adequate sample sizes, as well as to provide long-term monitoring of eel responses to river restoration, this study emphasizes the need for whole-catchment efforts in European eel conservation that combine river–floodplain restoration with greatly improved fish passage.https://www.kmae-journal.org/articles/kmae/full_html/2024/01/kmae240069/kmae240069.htmlriver glavenrestorationmark-and-recapturefish passagebefore-after-control-impact
spellingShingle Champkin James D.
Bašić Tea
Haubrock Phillip J.
Balzani Paride
Sayer Carl D.
George Laura K.
Godard Michael J.
Vilizzi Lorenzo
Copp Gordon H.
Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
Knowledge and Management of Aquatic Ecosystems
river glaven
restoration
mark-and-recapture
fish passage
before-after-control-impact
title Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
title_full Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
title_fullStr Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
title_full_unstemmed Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
title_short Short-term growth, movement and response of European eel Anguilla anguilla to re-meandering of a small English chalk stream
title_sort short term growth movement and response of european eel anguilla anguilla to re meandering of a small english chalk stream
topic river glaven
restoration
mark-and-recapture
fish passage
before-after-control-impact
url https://www.kmae-journal.org/articles/kmae/full_html/2024/01/kmae240069/kmae240069.html
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