Influence of seasonal primary productivity on δ13C of North Atlantic deep-sea benthic foraminifera

The stable isotopic composition of benthic foraminifera has been widely used to reconstruct deep-ocean circulation, but questions have been raised about the influence of organic carbon flux on the carbon isotopic composition of deep-sea taxa. We show that annual and seasonality of primary productivity in the North Atlantic do not affect delta C-13 of Planulina wuellerstorfi, but that the intermittency or seasonality of primary production has a significant effect (0.9%. change over 60 degrees latitude) on delta C-13 of Epistominella exigua, reflecting the influence of pelagic-benthic coupling and microhabitat preferences on test geochemistry. These results support the use of delta C-13 of p. wuellerstorfi in paleocirculation studies and suggest that the delta C-13 of E exigua can be used to reconstruct seasonality of productivity. (c) 2006 Elsevier Ltd. All rights reserved.