Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal

Detalhes bibliográficos
Autor(a) principal: Teixeira, Amílcar
Data de Publicação: 2006
Outros Autores: Cortes, Rui M.V., Oliveira, Daniel
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10198/998
Resumo: Habitat use by stocked and native brown trout (Salmo trutta L.) was assessed in two headwater streams of northeastern Portugal. Underwater observations were made during the summer season in three successive years to evaluate the effect of supplemental trout stocking. Multivariate analysis techniques applied to microhabitat use data sets were used to identify the focal elevation (distance of fish from the bottom), total depth and cover as the variables that contribute most to the discrimination between stocked and native trout. Preference curves computed for native and stocked trout of the same age (1+), showed a distinct pattern in their ability to explore the available microhabitat resources. Stocked trout tended to occupy deeper pools (total depth > 100 cm vs. 60-100 cm for native trout), holding higher focal elevations (140-160 cm vs. < 20 cm for native) with lower water column velocities (< 10 cm.s-1 vs. 10-20 cm.s-1 for native) and no specific preference for cover. In contrast, native trout displayed a clear preference for microhabitats with coarse substrate (particle size > 22.5 cm) and cover (combination of boulders and overhanging vegetation or undercut banks). Furthermore, a high post-stocking movement of 80 % hatchery-reared fish was verified just one month after their release, suggesting that stocking did not contribute to the sustainable populations in either stream, and is far from being an adequate management technique.
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spelling Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, PortugalSalmo truttaSnorkellingRestockingMicrohabitatPreference curvesHabitat use by stocked and native brown trout (Salmo trutta L.) was assessed in two headwater streams of northeastern Portugal. Underwater observations were made during the summer season in three successive years to evaluate the effect of supplemental trout stocking. Multivariate analysis techniques applied to microhabitat use data sets were used to identify the focal elevation (distance of fish from the bottom), total depth and cover as the variables that contribute most to the discrimination between stocked and native trout. Preference curves computed for native and stocked trout of the same age (1+), showed a distinct pattern in their ability to explore the available microhabitat resources. Stocked trout tended to occupy deeper pools (total depth > 100 cm vs. 60-100 cm for native trout), holding higher focal elevations (140-160 cm vs. < 20 cm for native) with lower water column velocities (< 10 cm.s-1 vs. 10-20 cm.s-1 for native) and no specific preference for cover. In contrast, native trout displayed a clear preference for microhabitats with coarse substrate (particle size > 22.5 cm) and cover (combination of boulders and overhanging vegetation or undercut banks). Furthermore, a high post-stocking movement of 80 % hatchery-reared fish was verified just one month after their release, suggesting that stocking did not contribute to the sustainable populations in either stream, and is far from being an adequate management technique.ONEMA - Office National de L’eau et des Milieux AquatiquesBiblioteca Digital do IPBTeixeira, AmílcarCortes, Rui M.V.Oliveira, Daniel2009-01-29T16:35:31Z20062006-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10198/998engTeixeira, Amílcar; Cortes, Rui; Oliveira, Daniel (2006). Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal. Bulletin Français de la Pêche et de la Pisciculture. ISSN 1297-6318. 382 (2006) p. 1-181297-631810.1051/kmae:2006004info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-21T10:04:14Zoai:bibliotecadigital.ipb.pt:10198/998Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:54:36.683100Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
title Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
spellingShingle Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
Teixeira, Amílcar
Salmo trutta
Snorkelling
Restocking
Microhabitat
Preference curves
title_short Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
title_full Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
title_fullStr Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
title_full_unstemmed Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
title_sort Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
author Teixeira, Amílcar
author_facet Teixeira, Amílcar
Cortes, Rui M.V.
Oliveira, Daniel
author_role author
author2 Cortes, Rui M.V.
Oliveira, Daniel
author2_role author
author
dc.contributor.none.fl_str_mv Biblioteca Digital do IPB
dc.contributor.author.fl_str_mv Teixeira, Amílcar
Cortes, Rui M.V.
Oliveira, Daniel
dc.subject.por.fl_str_mv Salmo trutta
Snorkelling
Restocking
Microhabitat
Preference curves
topic Salmo trutta
Snorkelling
Restocking
Microhabitat
Preference curves
description Habitat use by stocked and native brown trout (Salmo trutta L.) was assessed in two headwater streams of northeastern Portugal. Underwater observations were made during the summer season in three successive years to evaluate the effect of supplemental trout stocking. Multivariate analysis techniques applied to microhabitat use data sets were used to identify the focal elevation (distance of fish from the bottom), total depth and cover as the variables that contribute most to the discrimination between stocked and native trout. Preference curves computed for native and stocked trout of the same age (1+), showed a distinct pattern in their ability to explore the available microhabitat resources. Stocked trout tended to occupy deeper pools (total depth > 100 cm vs. 60-100 cm for native trout), holding higher focal elevations (140-160 cm vs. < 20 cm for native) with lower water column velocities (< 10 cm.s-1 vs. 10-20 cm.s-1 for native) and no specific preference for cover. In contrast, native trout displayed a clear preference for microhabitats with coarse substrate (particle size > 22.5 cm) and cover (combination of boulders and overhanging vegetation or undercut banks). Furthermore, a high post-stocking movement of 80 % hatchery-reared fish was verified just one month after their release, suggesting that stocking did not contribute to the sustainable populations in either stream, and is far from being an adequate management technique.
publishDate 2006
dc.date.none.fl_str_mv 2006
2006-01-01T00:00:00Z
2009-01-29T16:35:31Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10198/998
url http://hdl.handle.net/10198/998
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Teixeira, Amílcar; Cortes, Rui; Oliveira, Daniel (2006). Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal. Bulletin Français de la Pêche et de la Pisciculture. ISSN 1297-6318. 382 (2006) p. 1-18
1297-6318
10.1051/kmae:2006004
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv ONEMA - Office National de L’eau et des Milieux Aquatiques
publisher.none.fl_str_mv ONEMA - Office National de L’eau et des Milieux Aquatiques
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv
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