Inter-shelf nutrient transport from the East China Sea as a major nutrient source supporting winter primary production on the northeast South China Sea shelf

摘要

The East China Sea (ECS) and the South China Sea (SCS) are twomajor marginal seas of the North Pacific with distinct seasonal variationsof primary productivity. Based upon field observations covering both the ECSand the northern SCS (NSCS) during December 2008–January 2009, we examinedsouthward long-range transport of nutrients from the ECS to the northeasternSCS (NESCS) carried by the China Coastal Current (CCC) driven by theprevailing northeast monsoon in wintertime. These escaped nutrients from theECS shelf, where primary production (PP) was limited in winter, might howeverrefuel the PP on the NESCS shelf at lower latitude, where the watertemperature remained favorable, but river-sourced nutrients were limited. Bycombining the field observation of nitrate+nitrite (NO₃+NO₂,DIN) with our best estimate of volume transport of the CCC, we derived afirst-order estimate for DIN flux of 1430 ± 1024 mol s?1. Underthe assumption that DIN was the limiting nutrient, such southward DINtransport would have stimulated 8.84 ± 6.33 × 1011 gC ofnew production (NP), accounting for 33–74% of the NP or 14–22% of PPin winter on the NESCS shelf shallower than 100 m.