Year: 1993
Type: article
Abstract: The lowest biogenic silica production rates in the Southern Ocean (average of 2.59 mm01 Si m-2 d-l) have been recorded in an area of heavy ice cover along a transect through the Weddell Sea from Joinville Island to Cap Norvegia (November-December 1990).The associated biomass was also very low (concentrations 50.6 pm01 1-I for biogenic silica and S0.8 pg I-' for chlorophyll a ) .Based upon these direct measurements of biogenic silica production rates and other data available from the marginal ice zone and open ocean areas, we estimated the annual production of biogenlc silica in the northern Weddell Sea to be 810 to 870 rnrnol m-2 yrrl.Thls leads to a revised estimate of the total annual biogenic s d x a production in the Southern Ocean of between 11 and 32 Tmol Si yr-l.Comparing our annual production estimate to previous estimates of vertical flux of opal in the Weddell Sea, we conclude that no more than 1 % of the silica produced annually by phytoplankton in the upper water column reaches a depth of 800 m.This is consistent with the general distribution of high accumulation rates of opal in Southern Ocean sedirnents which evidence an unexplained gap in the Weddell Sea.Thus, regarding the cycling of biogenic s h c a in the Southern Ocean, the Weddell Sea appears to be atypical.
Source: Marine Ecology Progress Series
DOI: 10.3354/meps096001
Authors: A Leynaert, DM Nelson, B Quéguiner, P Treguer
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Life below water
Open Access status: bronze
OpenAlex ID: W2087864756