Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers
The upstream migration of European eels, Anguilla anguilla (L.), was studied during 1991–1993 in the Rivers Severn and Avon using traps mounted on weir or sluice barriers. Only pigmented elvers and juvenile eels were trapped at the tidal limits, catches being equivalent to about 0.8% of the commerci...
Published in: | Fisheries Management and Ecology |
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Language: | English |
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1997
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Online Access: | http://dx.doi.org/10.1046/j.1365-2400.1997.00050.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/full-xml/10.1046/j.1365-2400.1997.00050.x |
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crwiley:10.1046/j.1365-2400.1997.00050.x 2024-03-31T07:48:08+00:00 Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers WHITE, E. M. KNIGHTS, B. 1997 http://dx.doi.org/10.1046/j.1365-2400.1997.00050.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/full-xml/10.1046/j.1365-2400.1997.00050.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Fisheries Management and Ecology volume 4, issue 4, page 311-324 ISSN 0969-997X 1365-2400 Ecology Aquatic Science journal-article 1997 crwiley https://doi.org/10.1046/j.1365-2400.1997.00050.x 2024-03-05T05:57:07Z The upstream migration of European eels, Anguilla anguilla (L.), was studied during 1991–1993 in the Rivers Severn and Avon using traps mounted on weir or sluice barriers. Only pigmented elvers and juvenile eels were trapped at the tidal limits, catches being equivalent to about 0.8% of the commercial glass eel catch in the lower estuary. First catches were made as temperatures rose above 10–11 °C. Pigmentation‐stage analyses and body size data indicated that estuarine migration was slow and that natural mortality was probably very high. Relatively more eels were trapped in the Severn compared with the Avon, but in both rivers the number of immigrants decreased rapidly upstream of the tidal limits, whilst the average size and age increased. The number and severity of weir and sluice barriers to be surmounted exerted a greater effect than distance alone. Recapture rates of marked eels were low (1–2%), implying variable migratory tendencies and/or high mortality. Mean migration rate in the non‐tidal rivers was 0.64 ± 0.6 km day –1 and some eels were not recaptured until one or two years after release. Speed of migration increased with temperatures above 15–16 °C. Relationships between migration dynamics, barriers and the scarcity of upriver stocks of eels and distorted population structures in the two rivers are discussed. Recommendations are made for the provision of passes and/or stocking to enhance migration and recruitment. Article in Journal/Newspaper Anguilla anguilla Wiley Online Library Weir ENVELOPE(177.167,177.167,-84.983,-84.983) Fisheries Management and Ecology 4 4 311 324 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
topic |
Ecology Aquatic Science |
spellingShingle |
Ecology Aquatic Science WHITE, E. M. KNIGHTS, B. Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
topic_facet |
Ecology Aquatic Science |
description |
The upstream migration of European eels, Anguilla anguilla (L.), was studied during 1991–1993 in the Rivers Severn and Avon using traps mounted on weir or sluice barriers. Only pigmented elvers and juvenile eels were trapped at the tidal limits, catches being equivalent to about 0.8% of the commercial glass eel catch in the lower estuary. First catches were made as temperatures rose above 10–11 °C. Pigmentation‐stage analyses and body size data indicated that estuarine migration was slow and that natural mortality was probably very high. Relatively more eels were trapped in the Severn compared with the Avon, but in both rivers the number of immigrants decreased rapidly upstream of the tidal limits, whilst the average size and age increased. The number and severity of weir and sluice barriers to be surmounted exerted a greater effect than distance alone. Recapture rates of marked eels were low (1–2%), implying variable migratory tendencies and/or high mortality. Mean migration rate in the non‐tidal rivers was 0.64 ± 0.6 km day –1 and some eels were not recaptured until one or two years after release. Speed of migration increased with temperatures above 15–16 °C. Relationships between migration dynamics, barriers and the scarcity of upriver stocks of eels and distorted population structures in the two rivers are discussed. Recommendations are made for the provision of passes and/or stocking to enhance migration and recruitment. |
format |
Article in Journal/Newspaper |
author |
WHITE, E. M. KNIGHTS, B. |
author_facet |
WHITE, E. M. KNIGHTS, B. |
author_sort |
WHITE, E. M. |
title |
Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
title_short |
Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
title_full |
Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
title_fullStr |
Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
title_full_unstemmed |
Dynamics of upstream migration of the European eel, Anguilla anguilla (L.), in the Rivers Severn and Avon, England, with special reference to the effects of man‐made barriers |
title_sort |
dynamics of upstream migration of the european eel, anguilla anguilla (l.), in the rivers severn and avon, england, with special reference to the effects of man‐made barriers |
publisher |
Wiley |
publishDate |
1997 |
url |
http://dx.doi.org/10.1046/j.1365-2400.1997.00050.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2400.1997.00050.x https://onlinelibrary.wiley.com/doi/full-xml/10.1046/j.1365-2400.1997.00050.x |
long_lat |
ENVELOPE(177.167,177.167,-84.983,-84.983) |
geographic |
Weir |
geographic_facet |
Weir |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_source |
Fisheries Management and Ecology volume 4, issue 4, page 311-324 ISSN 0969-997X 1365-2400 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-2400.1997.00050.x |
container_title |
Fisheries Management and Ecology |
container_volume |
4 |
container_issue |
4 |
container_start_page |
311 |
op_container_end_page |
324 |
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1795028793519243264 |