Preliminary biological characterization of the Saldanha hydrothermal field at the Mid-Atlantic Ridge (36 degrees 34 ' N, 32 degrees 26 ' W, 2200 m)
|Author(s)||Biscoito M1, Almeida A2, Segonzac Michel3|
|Affiliation(s)||1 : IMAR, Estacao Biol Marinha Funchal, P-9000107 Madeira, Portugal.
2 : Univ Lisbon, Fac Ciencias, DBA, Lab Maritimo Guia,IMAR, P-2750642 Cascais, Portugal.
3 : IFREMER, Ctr Brest, DEEP, F-29280 Plouzane, France.
|Source||Cahiers de Biologie Marine (0007-9723) (Station Biologique de Roscoff), 2006-12 , Vol. 47 , N. 4 , P. 421-427|
|WOS© Times Cited||2|
|Keyword(s)||New records, Antimora, Acanthonus, Fish, Sponge, Bathyal megafauna, Gastropoda, Fauna assemblage, Mid Atlantic Ridge, Hydrothermal vents|
|Abstract||A preliminary description of the biology of the Saldanha hydrothermal field in the Mid-Atlantic Ridge (36 degrees 34'N, 32 degrees 26'W, 2200 m) is given, based on direct observation, video images and samples. Venting occurs mainly in a diffuse way through sediment, but hydrothermal fluid discharges are visible through centimeter-long orifices, scattered on the sediment, over an area of approximately 400 m(2), at depths between 2,200 and 2,220 metres. Emitted fluids are transparent, with a temperature of 7-9 degrees C. An almost complete absence of macro- and megafauna around the venting orifices was found. The only vent invertebrate identified was the gastropod Phymorhynchus sp., with only two juvenile specimens caught. A careful examination of the images taken at these orifices showed bacteria-like filaments undulating with fluid discharge. At the level of the benthic bathyal megafauna the dominant species seemed to be the sponge Cinachyra sp. (Demospongiae, Spirophorida, Tetillidae). At least 4 species of fish are new records from the area.|