Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla)
We examined the connection between descent of European silver eels (Anguilla anguilla) and water discharge, water temperature, turbidity, photoperiod, light intensity, and moon phase based on 10 yr of field data and field experiments. The eel migration takes place between August and December, and me...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Canadian Science Publishing
1986
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Online Access: | http://dx.doi.org/10.1139/f86-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/f86-236 |
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crcansciencepubl:10.1139/f86-236 2024-09-15T17:39:37+00:00 Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) Vøllestad, L. A. Jonsson, B. Hvidsten, N. A. Næsje, T. F. Haraldstad, Ø. Ruud-Hansen, J. 1986 http://dx.doi.org/10.1139/f86-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/f86-236 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 43, issue 10, page 1909-1916 ISSN 0706-652X 1205-7533 journal-article 1986 crcansciencepubl https://doi.org/10.1139/f86-236 2024-08-08T04:13:35Z We examined the connection between descent of European silver eels (Anguilla anguilla) and water discharge, water temperature, turbidity, photoperiod, light intensity, and moon phase based on 10 yr of field data and field experiments. The eel migration takes place between August and December, and mean water temperature for July–August and mean water discharge for August–October explained 91% of the total variation in the start of the yearly silver eel run. Low mean water temperatures during July–August and high mean water discharge during August–October resulted in an early start of the yearly silver eel run, whereas high mean water temperature and low water discharge gave the opposite effect. There was no significant correlation between the duration of the entire yearly silver eel run and the environmental variables investigated. But the duration of a part of the run, e.g. number of days from 5 to 25% cumulative eel descent, was significantly correlated with mean water temperature and increase in water discharge for the period in question (R 2 = 0.84). Maximum silver eel descent was at a water temperature of 9 °C. Few silver eels descended at temperatures below 4 °C or above 18 °C. The migration speed of transplanted silver eels in the River Imsa was correlated with water discharge and water temperature (R 2 = 0.88). Water discharge alone explained 85% of the total variation in migration speeds. The recapture rate of silver eels transplanted within the River Imsa was highest at 9 °C and decreased at higher and lower temperatures (R 2 = 0.95). Illumination of 20 lx upon the river reduced the descent of silver eels. Article in Journal/Newspaper Anguilla anguilla Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 43 10 1909 1916 |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
We examined the connection between descent of European silver eels (Anguilla anguilla) and water discharge, water temperature, turbidity, photoperiod, light intensity, and moon phase based on 10 yr of field data and field experiments. The eel migration takes place between August and December, and mean water temperature for July–August and mean water discharge for August–October explained 91% of the total variation in the start of the yearly silver eel run. Low mean water temperatures during July–August and high mean water discharge during August–October resulted in an early start of the yearly silver eel run, whereas high mean water temperature and low water discharge gave the opposite effect. There was no significant correlation between the duration of the entire yearly silver eel run and the environmental variables investigated. But the duration of a part of the run, e.g. number of days from 5 to 25% cumulative eel descent, was significantly correlated with mean water temperature and increase in water discharge for the period in question (R 2 = 0.84). Maximum silver eel descent was at a water temperature of 9 °C. Few silver eels descended at temperatures below 4 °C or above 18 °C. The migration speed of transplanted silver eels in the River Imsa was correlated with water discharge and water temperature (R 2 = 0.88). Water discharge alone explained 85% of the total variation in migration speeds. The recapture rate of silver eels transplanted within the River Imsa was highest at 9 °C and decreased at higher and lower temperatures (R 2 = 0.95). Illumination of 20 lx upon the river reduced the descent of silver eels. |
format |
Article in Journal/Newspaper |
author |
Vøllestad, L. A. Jonsson, B. Hvidsten, N. A. Næsje, T. F. Haraldstad, Ø. Ruud-Hansen, J. |
spellingShingle |
Vøllestad, L. A. Jonsson, B. Hvidsten, N. A. Næsje, T. F. Haraldstad, Ø. Ruud-Hansen, J. Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
author_facet |
Vøllestad, L. A. Jonsson, B. Hvidsten, N. A. Næsje, T. F. Haraldstad, Ø. Ruud-Hansen, J. |
author_sort |
Vøllestad, L. A. |
title |
Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
title_short |
Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
title_full |
Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
title_fullStr |
Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
title_full_unstemmed |
Environmental Factors Regulating the Seaward Migration of European Silver Eels ( Anguilla anguilla) |
title_sort |
environmental factors regulating the seaward migration of european silver eels ( anguilla anguilla) |
publisher |
Canadian Science Publishing |
publishDate |
1986 |
url |
http://dx.doi.org/10.1139/f86-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/f86-236 |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 43, issue 10, page 1909-1916 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f86-236 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
43 |
container_issue |
10 |
container_start_page |
1909 |
op_container_end_page |
1916 |
_version_ |
1810481278624989184 |