Challenges to quantifying glass eel abundance from large and dynamic estuaries
Abstract European eel Anguilla anguilla recruitment into the rivers of the northeastern Atlantic has declined substantially since the 1980s. Monitoring of recruiting juveniles, or glass eels, is usually undertaken in small estuaries and rivers. Sampling of large-scale estuaries is rare, due to the s...
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsx182 http://academic.oup.com/icesjms/article-pdf/75/2/727/31237197/fsx182.pdf |
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croxfordunivpr:10.1093/icesjms/fsx182 2023-10-01T03:50:18+02:00 Challenges to quantifying glass eel abundance from large and dynamic estuaries Walmsley, Sarah Bremner, Julie Walker, Alan Barry, Jon Maxwell, David Durif, Caroline 2017 http://dx.doi.org/10.1093/icesjms/fsx182 http://academic.oup.com/icesjms/article-pdf/75/2/727/31237197/fsx182.pdf en eng Oxford University Press (OUP) ICES Journal of Marine Science volume 75, issue 2, page 727-737 ISSN 1054-3139 1095-9289 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2017 croxfordunivpr https://doi.org/10.1093/icesjms/fsx182 2023-09-08T10:46:23Z Abstract European eel Anguilla anguilla recruitment into the rivers of the northeastern Atlantic has declined substantially since the 1980s. Monitoring of recruiting juveniles, or glass eels, is usually undertaken in small estuaries and rivers. Sampling of large-scale estuaries is rare, due to the size of the sampling area and the resources needed to provide adequate sampling levels. Here we describe surveys for glass eels in the UK’s largest estuarine system, the Severn Estuary/Bristol Channel. We sampled across a 20 km-wide stretch of the estuary in 2012 and 2013, using a small-meshed net deployed from a commercial fishing trawler, and the surveys yielded over 2500 glass eels. Eels were more abundant in the surface layer (0–1.4 m depth) than at depth (down to 8.4 m depth), were more abundant close to the south shore than along the north shore or middle of the estuary, and were more abundant in lower salinity water. Numbers were higher in the second year than in the first and eels were more abundant in February than April. The difficulties and logistics of sampling in such a large estuary are discussed, along with the level of resources required to provide robust estimates of glass eel abundance. Article in Journal/Newspaper Anguilla anguilla Oxford University Press (via Crossref) ICES Journal of Marine Science 75 2 727 737 |
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Open Polar |
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Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
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Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography Walmsley, Sarah Bremner, Julie Walker, Alan Barry, Jon Maxwell, David Challenges to quantifying glass eel abundance from large and dynamic estuaries |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract European eel Anguilla anguilla recruitment into the rivers of the northeastern Atlantic has declined substantially since the 1980s. Monitoring of recruiting juveniles, or glass eels, is usually undertaken in small estuaries and rivers. Sampling of large-scale estuaries is rare, due to the size of the sampling area and the resources needed to provide adequate sampling levels. Here we describe surveys for glass eels in the UK’s largest estuarine system, the Severn Estuary/Bristol Channel. We sampled across a 20 km-wide stretch of the estuary in 2012 and 2013, using a small-meshed net deployed from a commercial fishing trawler, and the surveys yielded over 2500 glass eels. Eels were more abundant in the surface layer (0–1.4 m depth) than at depth (down to 8.4 m depth), were more abundant close to the south shore than along the north shore or middle of the estuary, and were more abundant in lower salinity water. Numbers were higher in the second year than in the first and eels were more abundant in February than April. The difficulties and logistics of sampling in such a large estuary are discussed, along with the level of resources required to provide robust estimates of glass eel abundance. |
author2 |
Durif, Caroline |
format |
Article in Journal/Newspaper |
author |
Walmsley, Sarah Bremner, Julie Walker, Alan Barry, Jon Maxwell, David |
author_facet |
Walmsley, Sarah Bremner, Julie Walker, Alan Barry, Jon Maxwell, David |
author_sort |
Walmsley, Sarah |
title |
Challenges to quantifying glass eel abundance from large and dynamic estuaries |
title_short |
Challenges to quantifying glass eel abundance from large and dynamic estuaries |
title_full |
Challenges to quantifying glass eel abundance from large and dynamic estuaries |
title_fullStr |
Challenges to quantifying glass eel abundance from large and dynamic estuaries |
title_full_unstemmed |
Challenges to quantifying glass eel abundance from large and dynamic estuaries |
title_sort |
challenges to quantifying glass eel abundance from large and dynamic estuaries |
publisher |
Oxford University Press (OUP) |
publishDate |
2017 |
url |
http://dx.doi.org/10.1093/icesjms/fsx182 http://academic.oup.com/icesjms/article-pdf/75/2/727/31237197/fsx182.pdf |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_source |
ICES Journal of Marine Science volume 75, issue 2, page 727-737 ISSN 1054-3139 1095-9289 |
op_doi |
https://doi.org/10.1093/icesjms/fsx182 |
container_title |
ICES Journal of Marine Science |
container_volume |
75 |
container_issue |
2 |
container_start_page |
727 |
op_container_end_page |
737 |
_version_ |
1778521592187322368 |