| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Biodiversité et dynamique des peuplements ichtyiques de la mangrove de Guaratuba, Brésil
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| Autores: |
Chaves, P
Bouchereau, Jl
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| Data: |
1999-05
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| Ano: |
1999
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| Palavras-chave: |
Pisces
Organisation
Domaine paralique
Mangrove
Atlantique ouest
Pisces
Organisation
Paralic realm
Mangrove
Western Atlantic
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| Resumo: |
The Bay of Guaratuba, whose area is approximately 45 km(2), is a basin, situated to the south of Brazil (25 degrees 52' S; 48 degrees 39' W) and connected to the Atlantic ocean. In its northern part, a region of mangrove is found, under the influence of seasonal fluvial contributions, dominated by Laguncularia racemosa. The depth exceeds 6 m in some places. According to the period of the year, salinity varies between 3 and 37, and temperature between 15 and 28 degrees C. Several of the present fish species are exploited by commercial and recreational fisheries. This work describes characteristics of the fish populations occupying this mangrove, and temporal and spatial evolution of populations of the main species from available data on their biology. Between September 1993 and August 1996, fish samplings have been undertaken monthly by trawl, according to the same fishing effort (20 min), in channels of this ecosystem. Size, numerical abundance and weight of each individual of species were measured, as well as surface and bottom temperatures and bottom salinity. Species richness, Shannon-Weaver's diversity index were calculated and abundances were processed by the multivaried analysis. The global species richness is 61 species, distributed in 28 families; the better represented species are Sciaenidae (10), Gerreidae (5), Carangidae (5), Ariidae (4), Haemulidae (3), Serranidae (3), Bothidae (3). Each year, the number of species varies between 41 and 44, and a group of eight species represents between 80 to 90 % of the density and 75 % of the biomass. The constancy of this dominance is the main characteristic of this fish assemblage. The most represented species in abundance is Pomadasys corvinaeformis is the first two years, then Stellifer rastrifer. The group of eight main species is shared by 15 species in total, of which 13 for the density and 14 for the biomass. The most important monthly catches take place in winter season, during which one observes a decrease of water temperature and an increase of salinity. These species, however, being likely to be replaced by others according to the year or the season; one never finds the same composition in the assemblage which pre serves always the same structures. Seasonal differences between seasons under marine (winter) and continental (summer) influences play a major role on the dynamics of fish in the Guaratuba mangrove. This ecosystem plays a functional role in the achievement of the life cycle of many permanent or temporary species. Those having succeeded to reach high levels of abundance are not represented in a uniform way in the course of the year, even when they reside permanently in the ecosystem. Periodic displacement strategies for self regulation of stocks abundance, are necessary mechanisms for these populations. which thus success to coexist in occupying the mangrove.
A partir de pêches mensuelles d'échantillonnage effectuées entre septembre 1993 et août 1996 dans les chenaux de la mangrove de la baie de Guaratuba, Brésil, nous avons répertorié un total de 61 espèces de poissons d'origine marine, en majorité de petites tailles. L'organisation de l'assemblage conserve toujours la même structure générale, à laquelle 15 espèces ont principalement participé. Chaque année, huit espèces sur les 15 sont responsables de 80 % de l'abondance relative. Les paramètres abiotiques et les descripteurs de l'assemblage varient au cours du temps. En été, l'influence continentale est plus élevée qu'en hiver. Entre ces deux saisons, en automne, la diversité connaît des variations plus fortes que pendant le reste de l'année, alors que la richesse spécifique atteint sa valeur maximale. Sur une période plus étendue. de la fin de l'automne au début du printemps, tout en reflétant les variations qui s'exercent selon l'année, l'abondance relative des effectifs atteint des valeurs maximales. Les mouvements de sortie et d'entrée génésiques et trophiques des différentes populations de poissons occupant la mangrove, mettent en évidence le rôle joué par cet écosystème en tant que lieu d'accueil temporaire ou permanent pour des espèces principalement d'origine thalassique
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| Tipo: |
Text
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| Idioma: |
Francês
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| Identificador: |
http://archimer.ifremer.fr/doc/00325/43615/43917.pdf
DOI:10.1016/S0399-1784(99)80057-7
http://archimer.ifremer.fr/doc/00325/43615/
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| Editor: |
Gauthier-villars/editions Elsevier
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| Formato: |
application/pdf
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| Fonte: |
Oceanologica Acta (0399-1784) (Gauthier-villars/editions Elsevier), 1999-05 , Vol. 22 , N. 3 , P. 353-364
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| Direitos: |
Elsevier, Paris / Ifremer / Cnrs / Ird
info:eu-repo/semantics/openAccess
restricted use
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