Áreas Marinas Protegidas - AMPhttp://hdl.handle.net/1834/161062024-03-28T23:59:58Z2024-03-28T23:59:58ZVema's Brachiopoda (Recent)Cooper, G.http://hdl.handle.net/1834/172362021-05-19T06:24:12Z1973-01-01T00:00:00ZVema's Brachiopoda (Recent)
Cooper, G.
G. Arthur Cooper. Vema's Brachiopods (Recent). Smithsonian Contributions to Paleobiology, number 17, 51 pages, 5 figures, 9„plates, 1973.—Brachiopods dredged on the worldwide exploratory cruises of R/V Vema, of the Lamont-Doherty Geological Observatory of Columbia University, are important in expanding knowledge of brachiopod distribution and taxonomy. Thirty-two species are identified, of which six are new. Twenty-one genera are represented, one of which is new. The species of five genera and the genera of two lots could not be determined. The majority of the brachiopods were taken from waters deeper than 100 fathoms. One specimen of Abyssothyris was dredged from the greatest depth (6179 meters=20,267 feet) from which a brachiopod has been taken.
1973-01-01T00:00:00ZUnveiling the submarine landscape of the Namuncurá Marine Protected Area, Burdwood Bank, SW Atlantic OceanSchejter, L.Martin, J.Lovrich, G.http://hdl.handle.net/1834/172352021-05-19T06:24:29Z2017-01-01T00:00:00ZUnveiling the submarine landscape of the Namuncurá Marine Protected Area, Burdwood Bank, SW Atlantic Ocean
Schejter, L.; Martin, J.; Lovrich, G.
In this contribution we provide the first images of the submarine landscape of the Namuncurá Marine Protected Area, Burdwood Bank, at the SW Atlantic Ocean. This noninvasive approach revealed and offered a complementary view of the seafloor and its fauna, only previously reported from trawl catches.
2017-01-01T00:00:00ZTransport and variability of the Antarctic Circumpolar Current in Drake PassageCunningham, S.Alderson, S.King, B.Brandon, M.http://hdl.handle.net/1834/172342021-05-19T06:24:14Z2003-01-01T00:00:00ZTransport and variability of the Antarctic Circumpolar Current in Drake Passage
Cunningham, S.; Alderson, S.; King, B.; Brandon, M.
1] The baroclinic transport of the Antarctic Circumpolar Current (ACC) above 3000 m through Drake Passage is 107.3 ± 10.4 Sv and has been steady between 1975 and 2000. For six hydrographic sections (1993–2000) along the World Ocean Circulation Experiment (WOCE) line SR1b, the baroclinic transport relative to the deepest common level is 136.7 ± 7.8 Sv. The ACC transport is carried in two jets, the Subantarctic Front 53 ± 10 Sv and the Polar Front (PF) 57.5 ± 5.7 Sv. Southward of the ACC the Southern Antarctic Circumpolar Current transports 9.3 ± 2.4 Sv. We observe the PF at two latitudes separated by 90 km. This bimodal distribution is related to changes in the circulation and properties of Antarctic Bottom Water. Three realizations of the instantaneous velocity field were obtained with lowered ADCPs. From these observations we obtain near‐bottom reference velocities for transport calculations. Net transport due to these reference velocities ranges from −28 to 43 Sv, consistent with previous estimates of variability. The transport in density layers shows systematic variations due to seasonal heating in near‐surface layers. Volume transport‐weighted mean temperatures vary by 0.40°C from spring to summer; a seasonal variation in heat flux of about 0.22 PW. Finally, we review a series of papers from the International Southern Ocean Studies Program. The average yearlong absolute transport is 134 Sv, and the standard deviation of the average is 11.2 Sv; the error of the average transport is 15 to 27 Sv. We emphasize that baroclinic variability is an important contribution to net variability in the ACC.
2003-01-01T00:00:00ZTintinnids (Cilophora) and other net microzooplankton (>30um) in South-western Atlantic Shelf Break WatersThompson, G.Alder, V.Boltovskoy, D.http://hdl.handle.net/1834/172332021-05-19T06:24:26Z2001-01-01T00:00:00ZTintinnids (Cilophora) and other net microzooplankton (>30um) in South-western Atlantic Shelf Break Waters
Thompson, G.; Alder, V.; Boltovskoy, D.
Proportions of foraminifers, tintinnids, polycystine radiolarians, pteropods and crustacean larval stages were estimated in a collection of 76 vertically stratified (0 – 100 m) 30 µm net microplankton samples from 16 stations along the Argentine shelf-slope (around 200 m isobath – between 40 and 56° S), covered on 13 – 18 November 1996. Tintinnids were identified to species. Relative abundances of the microzooplankton assessed and chlorophyll a values allow to define two contrasting groups of stations: ‘deep’ and ‘shallow’. The former, located in pelagic, purely subantarctic Malvinas Current waters, hosted higher proportions of foraminifers and lower proportions of tintinnids, as well as less chlorophyll a (all differences were significant at the 0.1 % level). ‘Shallow’ stations were located in the area of the thermohaline front where the Patagonian Current comes in contact with the Malvinas Current, and were generally characterized by higher chlorophyll a levels (up to 3.7 µg Chl a · l–1). The distribution of tintinnid species, on the other hand, allowed no discrimination between these two areas, although some of the dominant forms showed much higher relative abundances in one of the two groups of stations. Twenty-six tintinnid taxa were recorded, yet only 6 accounted for 95 % of the specimens identified. Tintinnid taxocoenoses were characterized by a few abundant species and many rare ones. Numbers of tintinnid species and specific diversity did not differ noticeably with depth and latitude. Cape Horn Current waters were detected in the area by the presence of expatriated organisms presumably originating at mid-latitudes in the South Pacific Ocean.
2001-01-01T00:00:00Z