Les diatomées dans l'upwelling de Cabo Frio (Brésil): liste d'espèces et étude écologique

Valentin, Jean Louis; Silva, Nadja M. Lins da; Bastos, Christina T. B

doi:10.1093/plankt/7.3.313

Cited by 14 publications

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“…The satellite track herein described suggest that C. leucas off Brazil might move through broad coastal areas, even though they tend to exhibit some level of residency in specific regions, as observed around highly productive areas from the North Atlantic (Carlson et al, 2010). In accordance, the longest residency period (17 days) measured in this study occurred in a region influenced by the Cabo Frio upwelling system (Valentin et al, 1985), suggesting that feeding responses might have influenced such a behavior. Besides, the shark dove to deeper isobaths of ca.…”

Section: Discussionsupporting

confidence: 78%

Bioecology and movements of bull sharks, Carcharhinus leucas , caught in a long-term longline survey off northeastern Brazil

2017

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Bioecology and movements of bull sharks, Carcharhinus leucas, caught in a long-term longline survey off northeastern BrazilYuri V. Niella 1, 2 , André S. Afonso 2 and Fábio H. V. Hazin 2 A robust understanding of habitat usage by coastal shark species, and how it overlaps with human presence in denselypopulated regions is needed to inform the development of efficient conservation strategies for these important top predators. An intensive longline survey conducted in nearshore waters off northeastern Brazil from 2004 through 2014 caught a total of 18 bull sharks (Carcharhinus leucas) (male-female ratio = 0.63:1), which can be dangerous to humans. Although most sharks were sexually mature, there was no evidence that this region could be used as a parturition or nursery area. Prey items identified in the guts of the sharks comprised teleosts, mollusks and elasmobranchs. Additionally, one satellite-tagged bull shark covered a great distance (> 3,000 km) in 75 days at liberty, making most use of shallow waters (< 20 m depth) and presumably also entering an estuarine area. Although bull sharks are not an important fishery resource in this region, such a reduced abundance coupled with its affinity for coastal and inshore habitats highlights the potential vulnerability of C. leucas to deleterious anthropic interferences off northeastern Brazil.Keywords: Drumline, Longline, Maturity status, Pop-up satellite archival tag, Recife.Um melhor entendimento sobre a utilização de hábitat das espécies de tubarões costeiros, e como ela se sobrepõe à presença humana em regiões altamente populosas, se faz necessário a fim de subsidiar o desenvolvimento de eficientes medidas de conservação para esses importantes predadores de topo. Um estudo intensivo utilizando espinhel, conduzido em águas costeiras do nordeste do Brasil entre os anos de 2004 e 2014, capturou um total de 18 tubarões cabeça-chata (Carcharhinus leucas) (proporção macho-fêmea = 0,63:1), os quais podem ser perigosos para humanos. Apesar da maioria dos tubarões estarem sexualmente maduros, não houve evidências de que essa região esteja sendo utilizada como uma área de parto ou berçário. Entre os itens alimentares identificados foram encontrados teleósteos, moluscos e elasmobrânquios. Além disso, um tubarão cabeça-chata marcado com um transmissor satélite percorreu uma grande distância (> 3.000 km) em 75 dias em liberdade, fazendo o uso de águas superficiais (< 20 m profundidade) e presumivelmente entrando em uma área estuarina. Apesar de os tubarões cabeça-chata não corresponderem a um recurso pesqueiro importante nessa região, tal reduzida abundância juntamente com a sua afinidade por hábitats costeiros reforçam a potencial vulnerabilidade de C. leucas às interferências antrópicas deletérias ao longo da costa nordeste do Brasil.

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Section: Discussionsupporting

confidence: 78%

Bioecology and movements of bull sharks, Carcharhinus leucas , caught in a long-term longline survey off northeastern Brazil

2017

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“…It was mainly observed in winter samples from nearshore to the shelf slope off both areas SMGC and AC, with higher occurrence frequency at SMGC. Northward in Brazilian coastal waters, A. flabellatus and A. heptactis were found under the influence of upwelling off Cabo Frio (23 o S; MACEDO et al, 1975;VALENTIN et al, 1985). Hernández-Becerril (1991) classified A. flabellatus as distributed worldwide in warm waters and A. heptactis as cosmopolitan.…”

Section: Discussionmentioning

confidence: 99%

Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters

Garcia

Odebrecht

2012

Braz. j. oceanogr.

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This paper provides information on the morphology and occurrence of extant diatoms of the family Asterolampraceae and Azpeitia species of the southernmost Brazilian continental shelf and slope waters in the Southwestern Atlantic Ocean (28 -34ºS), under the influence of Tropical, Subtropical, Subantarctic Waters, terrestrial discharges from La Plata River and Lagoa dos Patos lagoon. Plankton was sampled (20 µm net; vertical hauls) at the same 27 stations in winter 2005 and summer 2007. Among Asterolampraceae, Asteromphalus flabellatus was the most frequent species (57% of samples) observed mainly in winter samples (92%) in Subtropical Shelf Water but also under the influence of La Plata River plume (salinity <35). Lower frequencies were observed for Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne. Four species of Azpeitia were observed: A. barronii and A. neocrenulata for the first time in the South Atlantic Ocean while A. africana and A. nodulifer had already been registered in equatorial and southern areas of Brazil. All Azpeitia species were rare (19%) in offshore samples (100-200 m depth. Remarks on the morphology based on light and scanning electron microcopy observations are provided along with their distribution in the study area.

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“…Na costa tropical do Atlântico Sudoeste, a advecção da Água Central do Atlântico Sul (ACAS), fria e rica em nutrientes, nas águas superficiais caracterizam o sistema de ressurgência efêmero e incomum de Cabo Frio (Mascarenhas et al, 1971). Sob ventos prevalecentes de NE, a ressurgência da ACAS causa um aumento nas concentrações de nitrato (de 0,4 a 10,0 µM) da zona eufótica, e, conseqüentemente, florescimentos do fitoplâncton são comumente observados na plataforma interna Valentin et al, 1985). Na região de Cabo Frio a biomassa fitoplanctônica varia entre 5,0-25,5 mg clorofila-a m -3 durante o verão (Gonzalez-Rodriguez, 1991;Moser & Gianesella-Galvão, 1997).…”

Section: Variação Temporal Dos Inventários De Clorofila-aunclassified

“…Os SCFA associados à essa fração refratária da MO sedimentar podem ser conseqüência da degradação extensiva do material de plantas terrestres (ácidos graxos de cadeias muito longas >C 36 ) durante o transporte do continente para os sedimentos oceânicos. Os esteróis C 29 são comumente descritos como os principais esteróis em plantas superiores (Goad & Goodwin, 1972;Huang & Meinschein, 1976) e os resultados da análise de correlação demonstram que, ao menos parcialmente, os esteróis 29∆ 5,22E (Valentin et al, 1985). As altas concentrações de fitol, C 16:1ω7 , C 20:5ω3 , além dos esteróis C 28 , principalmente o 28∆ 5,24(28) , durante as amostragens de verão e primavera podem ser atribuídas ao aporte de diatomáceas (Tabela 3.5).…”

Section: Análises De Correlaçãounclassified

“…Este resultado concorda com o decréscimo acentuado na contribuição de diatomáceas em águas francamente oceânicas da costa SE do Brasil (e.g. Valentin et al, 1985;Brandini & Fernandes, 1996). Outro fator interessante é a reduzida qualidade da MO depositada nesses sedimentos, provavelmente refletindo o intenso retrabalhamento do material pelo bacterioplâncton durante os processos de sedimentação na coluna de água (e.g.…”

Section: Análises De Correlaçãounclassified

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"Origem e composição da matéria orgânica e a dinâmica da comunidade microbiana em sedimentos superficiais de ecossistemas marinhos da costa sudeste do Brasil"

Yoshinaga¹

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an extraordinary persona, whose effort to send me to CBL and teaching about organic stuff were crucial to my professional experience. If I were to nominate a mother in the USA this would have to be Joan Caruthers. Thanks for all the help, housing, dancing, pingpong, dinners, lunch, gifts, and every single stuff we did together, which all will be packed in my heart for the rest of my life. I'm in debt also with people from the Institutions I visited

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Les diatomées dans l'upwelling de Cabo Frio (Brésil): liste d'espèces et étude écologique

Cited by 14 publications

References 0 publications

Bioecology and movements of bull sharks, Carcharhinus leucas , caught in a long-term longline survey off northeastern Brazil

Bioecology and movements of bull sharks, Carcharhinus leucas , caught in a long-term longline survey off northeastern Brazil

Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters

"Origem e composição da matéria orgânica e a dinâmica da comunidade microbiana em sedimentos superficiais de ecossistemas marinhos da costa sudeste do Brasil"

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