Trophic Dynamics of Filter Feeding Bivalves in the Yangtze Estuarine Intertidal Marsh: Stable Isotope and XXXX Analyses.

@entity32544 @entity844 @entity2133 @entity7352 @entity505 @entity72114
UNASSIGNED: Benthic bivalves are important links between primary production and consumers, and are essential intermediates in the flow of energy through estuarine systems. However, information on the diet of filter feeding bivalves in estuarine ecosystems is uncertain, as estuarine waters contain particulate matter from a range of sources and as bivalves are opportunistic feeders. We surveyed bivalves at different distances from the @entity2133 at the Yangtze estuarine marsh in winter and summer, and analyzed trophic dynamics using stable isotope (SI) and @entity844 (FA) techniques. Different bivalve species had different spatial distributions in the estuary. Glauconome chinensis mainly occurred in marshes near the @entity2133 , while @entity72114 preferred the creek. Differences were found in the diets of different species. @entity72114 consumed more diatoms and bacteria than @entity32544 , while @entity32544 assimilated more macrophyte material. FA markers showed that plants contributed the most (38.86    4.25%) to particular organic matter (POM) in summer, while diatoms contributed the most (12.68    1.17%) during winter. Diatoms made the largest contribution to the diet of @entity72114 in both summer (24.73    0.44%) and winter (25.51    0.59%), and plants contributed no more than 4%. This inconsistency indicates seasonal changes in food availability and the active feeding habits of the bivalve. Similar FA profiles for @entity72114 indicated that the bivalve had a similar diet composition at different sites, while different   @entity7352 results suggested the diet was derived from different @entity505 sources (C4 plant Spartina alterniflora and C3 plant Phragmites australis and Scirpus mariqueter) at different sites. Species-specific and temporal and/or spatial variability in bivalve feeding may affect their ecological functions in intertidal marshes, which should be considered in the study of food webs and material flows in estuarine ecosystems.
