查看文章

Suspended particulate organic matter was sampled monthly between June 1999 and April 2000 in the Scheldt river and estuary to investigate the seasonal and spatial patterns of δ¹³C and δ¹⁵N signatures. δ¹⁵N of suspended matter showed large seasonal variation. Minimum values ranged from −0.5‰ in the freshwater zone (spring situation) to +2.3‰ in the mesohaline zone (winter situation). Maximum values (summer situation) ranged from +8.8‰ in the freshwater zone to +12.9‰ in the mesohaline zone. δ¹³C showed less seasonal variation and ranged overall from −31.1‰ in the freshwater zone to −23.7‰ in the mesohaline zone. During the growth season, decrease of δ¹³C and increase of δ¹⁵N of suspended matter were due to local phytoplanktonic and bacterial biomass. There is strong evidence that the ¹⁵N enrichment of suspended matter during the growth season reflects the ¹⁵N enrichment of the …