Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 55 (2008): 2118-2131, doi:10.1016/j.dsr2.2008.04.028.
Description:
Includes supplemental materials
Description:
We report on results of a long-term (1993-2007) time series sediment trap moored at 170 m to
the west of the Antarctic Peninsula in the mid-continental shelf region (350 m depth; 64º30’ S,
66º00’ W). This is a region characterized by late spring-summer diatom blooms, moderately high
seasonal primary productivity (50-150 mmol C m-2 d-1 in December-February) and high
phytoplankton and krill biomass in the seasonal sea ice zone. The mass flux ranged from near 0
to over 1 g m-2 d-1 and was near 0 to 〉30% organic carbon (mean 8%). Sedimentation from the
upper ocean as estimated by the trap collections at 170 m exhibited strong seasonality with high
fluxes (1-10 mmol C m-2 d-1) in November-March following ice retreat and very low fluxes
(〈0.001 mmol C m-2 d-1) during the Austral winter and under sea ice cover. An average of 85%
of the annual export of 212 mmol C m-2 occurred during the seasonal peak flux episodes. Over
the trap record, the annual peak flux episode has tended to occur later in the Austral summer,
advancing by about 40 days since 1993. The time-integrated sedimentation during the peak flux
episode was 〈1 – 50% of the SeaWiFS-estimated primary production (mean 4%) at the trap site
over the period 1998-2006. The elemental composition of material captured in the traps had an
average C:N:P of 212:28:1, greater than the canonical Redfield values. High C:P ratios (400-
600) corresponded with the annual flux peak, indicating preferential loss of P from the sinking
particles in the summer, ice-free period. The composition of the exported material more closely
approximated the Redfield composition during the low-flux, winter period.
Description:
This research was supported by NSF Grants OPP 9011927, 9632763 and 0217282 for the
Palmer Long Term Ecological Research project.
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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