Latitudinal distributions of particulate carbon export across the North Western Atlantic Ocean

The great hammerhead shark, Sphyrna mokarran, is a cosmopolitan species that is caught in a variety of fisheries throughout much of its range. The apparent decline of great hammerhead shark populations has reinforced the need for accurate biological data to enhance fishery management plans. To this end, age and growth estimates for the great hammerhead were determined from sharks (n = 216) ranging in size from 54- to 315-cm fork length (FL), captured in the Gulf of Mexico and north-western Atlantic Ocean. Growth curves were fitted using multiple models and evaluated using Akaike’s information criterion. The von Bertalanffy growth model was the best fitting model, with resulting growth parameters of L∞ = 264.2-cm FL, k = 0.16 year–1, t0 = –1.99 year for males, and L∞ = 307.8-cm FL, k = 0.11 year–1, t0 = –2.86 year for females. Annual band pair deposition was confirmed through marginal-increment analysis and a concurrent bomb radiocarbon validation study. Great hammerheads have one of the oldest reported ages for any elasmobranch (44 years) but grow at relatively similar rates (on the basis of von Bertalanffy k value) to other large hammerhead species from this region. The present study is the first to provide vertebral ages for great hammerheads.

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Geological and geochemical data for sediment and pore water samples from the Sohm Abyssal Plain, north western Atlantic Ocean

10.4095/129842 ◽

1984 ◽

Author(s):

G V Winters ◽

D E Buckley ◽

R E Cranston ◽

R A Fitzgerald ◽

M Stoffyn ◽

...

Keyword(s):

Atlantic Ocean ◽

Pore Water ◽

Water Samples ◽

Abyssal Plain ◽

Geochemical Data ◽

Western Atlantic ◽

Western Atlantic Ocean ◽

North Western

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Remarks on the identification of the Albian/Cenomanian boundary and taxonomic clarification of the planktonic foraminifera index speciesglobotruncanoides, brotzeniandtehamaensis

Geological Magazine ◽

10.1017/s0016756814000478 ◽

2014 ◽

Vol 152 (3) ◽

pp. 521-536 ◽

Cited By ~ 15

Author(s):

MARIA ROSE PETRIZZO ◽

MICHÈLE CARON ◽

ISABELLA PREMOLI SILVA

Keyword(s):

Atlantic Ocean ◽

Planktonic Foraminifera ◽

Taxonomic Status ◽

Junior Synonym ◽

Western Atlantic ◽

Western Atlantic Ocean ◽

Unequivocal Identification ◽

Long Time ◽

Stratotype Section ◽

North Western

AbstractThe planktonic foraminifera assemblage across the Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage defined at Mont Risou (Haute-Alpes in France) is here restudied to clarify the identification and stratigraphic distribution ofThalmanninella globotruncanoides( =Rotalipora globotruncanoidesSigal, 1948) andPseudothalmanninella tehamaensis( =Rotalipora tehamaensisMarianos & Zingula, 1966) whose appearance levels are primary and secondary criteria for placing the Albian/Cenomanian boundary. Since the ratification of the GSSP in 2002, the identification of the foraminifera index species across the Albian/Cenomanian boundary has been reported to be sometimes difficult either because of their rarity or uncertainty in the taxonomic identifications. We discuss the taxonomic status ofThalmanninella brotzeniSigal 1948, a species regarded for a long time to be a junior synonym ofTh. globotruncanoides, through images of Sigal's type materials deposited at the Musée National d’Histoire Naturelle (Paris), and elucidate the taxonomically important characters that enable unequivocal identification ofTh. brotzeni, Th. globotruncanoidesandPs. tehamaensis. Planktonic foraminifera marker species from Mont Risou are compared with well-preserved specimens from Blake Nose Plateau (ODP 171B, North Western Atlantic Ocean) to verify the reliability and stratigraphic distribution of these marker taxa outside the Mediterranean Tethyan area.

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