Spartina anglica as a Carbon Source for Salt-Marsh Invertebrates: A Study Using δ 13 C Values

Abstract

Relative and absolute assimilation rates in macro-invertebrates on a salt-marsh in east England, dominated by Spartina anglica, were calculated for 1979 and 1980, using a combination of 513C values and faecal analyses. Total assimilation of S. anglica was around 40-45 g C m-2, which represents up to 20% of annual net primary shoot production (ANPPs). Of this, Nereis diversicolor accounted for >85% of the collective S. anglica assimilated by all macro-invertebrates. Fauna associated with the vegetation canopy assimilated only 0.5 g C m-2 (or < 0.3% of ANPPs). Analysis of bt3C values appears to offer a relatively simple means of investigating sources of carbon assimilated. Nevertheless, the limitations of the method are discussed.