Relationships between Antarctic coastal and deep-sea particle fluxes: implications for the deep-sea benthos

• Published in: Polar Biology
• Main Authors: Isla, Enrique, Gerdes, Dieter, Palanques, Albert, Teixidó, Núria, Arntz, Wolf, Puig, Pere
• Other Authors: Institute of Marine Sciences / Institut de Ciències del Mar Barcelona (ICM), Consejo Superior de Investigaciones Científicas Madrid (CSIC), Hopkins Marine Station Stanford, Stanford University, Alfred Wegener Institute for Polar and Marine Research (AWI)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Antarctic; Antarctic Peninsula; Bransfield Strait; Livingston Island; Antarc*; Antarctica; Ice Shelves; Iceberg*; Polar Biology
• Online Access: https://hal.science/hal-00093814; https://hal.science/hal-00093814/document; https://hal.science/hal-00093814/file/Isla2006.pdf; https://doi.org/10.1007/s00300-005-0046-9

Downward particle fluxes measured by means of sediment traps to a shallow semi-closed bay (Johnson’s Dock, Livingston Island) and to a deep basin in the western Bransfield Strait (Antarctic Peninsula) showed the important role of glaciers as sediment carriers and suppliers to the ocean in a continent without major rivers such as Antarctica. The trap moored in Johnson’s Dock collected coarse sediment (>1 mm mesh) not observed in the offshore traps, which mainly received fine sediment and faecal pellets. The annual total mass flux (TMF) to the coastal zone (15 m) was 900- and three times that to mid-depth (500 m) and near-bottom (1,000 m) traps, respectively. The fine sediment flux was especially important due to its biogenic particle contents. Despite the differences in TMF to the coastal zone and near the bottom in the deep basin, the organic carbon (OC) flux was similar in both environments (16 and 18 g m−2, respectively), whereas biogenic silica (BSi) flux increased three times with depth (75 and 201 g m−2, respectively). These fluxes imply that an important part of the particulate organic matter deposited in the coastal zone is advected basinward within the fine-particle flux. Thus, benthos in deep areas depends largely on the lateral transport of biogenic material produced in shallow environments near the coast. It is also proposed that the disintegration of Antarctic ice shelves and the consequent increment of ice calving may produce local devastations of ecological importance not only on the shallow but also on the rich Antarctic deep-sea benthic communities due to an increment of iceberg scouring and reduction of the organic matter supply.