Natural 14C in Saccoglossus bromophenolosus compared to 14C in surrounding sediments

Abstract

The natural radiocarbon (14C) content of whole, gut voided Saccoglossus bromophenolosus collected in Lowes Cove, Maine, USA, was compared with that of a non-voided worm, sectioned individuals, and the natural product 2,4-dibromophenol (2,4-DBP) isolated from S. bromophenolosus. In all cases, the 14C content was greater than that of the sediment from which the enteropneusts were collected. The 14C content of 2 polychaetes, Glycera dibranchiata and Clymenella torquata, also collected from Lowes Cove, were similarly enriched in 14C compared to the bulk sediment. These results show that all 3 species consumed recently fixed carbon that was much newer than organic carbon in the bulk sediment. The value (+10.4‰) obtained for 2,4-DBP isolated from S. bromophenolosus in this study differs from that reported in a previous study (–170‰). The discrepancy is attributed to methodological differences. The importance of selecting an appropriate method when isolating compounds for natural abundance 14C analysis is discussed.