Habitat use by native and stocked trout (Salmo trutta L.) in two northeast streams, Portugal
Autor(a) principal: | |
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Data de Publicação: | 2006 |
Outros Autores: | , |
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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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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1817552807417348097 |