title: Occurrence and metabolic activity of organisms under the ross ice shelf, antarctica, at station j9.
abstract: Seawater samples below the Ross Ice Shelf were collected through an access hole at J9, approximately 400 kilometers from the Ross Sea, Antarctica. The 237-meter water column had sparse populations of bacteria (8.7 x 10(6) to 1.2 x 10(7) per liter), microplankters (10(2) to 10(3) per cubic meter), and zooplankters (10 to 20 per cubic meter) at the depths studied. Microbial biomass estimates from cellular adenosine 5'-triphosphate measurements were very low (10 to 150 nanograms of carbon per liter), comparable with values for the abyssal ocean. Microbial populations assimilated tritiated D-glucose, thymidine, uridine, and adenosine triphosphate at extremely low rates, comparable with deep-sea heterotrophic populations. Sediment samples had 10(7) to 10(8) bacteria per gram (dry weight), which were metabolically active as shown by respiration of uniformly labeled D-[(14)C]glucose. From this study it cannot be determined whether these organisms in the water column and sediments constitute a functioning food web.
authors.forename: F
authors.initials: F
authors.lastname: Azam
authors.forename: J R
authors.initials: JR
authors.lastname: Beers
authors.forename: L
authors.initials: L
authors.lastname: Campbell
authors.forename: A F
authors.initials: AF
authors.lastname: Carlucci
authors.forename: O
authors.initials: O
authors.lastname: Holm-Hansen
authors.forename: F M
authors.initials: FM
authors.lastname: Reid
authors.forename: D M
authors.initials: DM
authors.lastname: Karl