Seasonal variation in the diet of estuarine bivalves

DOI

Estuarine food webs are generally considered to be supported by marine pelagic and benthic primary producers and by the import of dead organic matter from the open sea. Although estuaries receive considerable amounts of freshwater phytoplankton and organic compounds from adjacent rivers, the potential contribution of these living and dead matter to estuarine food webs is often assumed to be negligible and, therefore, not examined. Based on stable isotope analyses, we report the importance of freshwater suspended particulate organic matter (FW-SPOM) for fuelling estuarine food webs in comparison to estuarine SPOM and microphytobenthos. On average throughout the year, this so-far neglected food source appeared to have contributed 50 %-60 % to the food intake of suspension-feeding bivalves such as cockles (Cerastoderma edule), mussels (Mytilus edulis) and pacific oysters (Magallana gigas) at the Balgzand tidal flats, an estuarine site in the western Wadden Sea (12-32 psu). For these species, this proportion was particularly high in autumn during strong run-off of SPOM-rich freshwater, whilst estuarine SPOM (20 %-25 %) and microphytobenthos (15 %-30 %) were relatively important in summer when the freshwater run-off was very low. These findings have implications for our understanding of the trophic interactions within coastal food webs and for freshwater management of estuarine ecosystems.

Identifier
DOI https://doi.org/10.17882/56438
Metadata Access http://www.seanoe.org/oai/OAIHandler?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai:seanoe.org:56438
Provenance
Creator Jung, Alexa Sarina; Van Der Veer, Henk W.; Van Der Meer, Marcel T.j.; Philippart, Catharina J.m.
Publisher Seanoe
Publication Year 2018
Rights CC-BY-NC-ND
OpenAccess true
Contact Seanoe
Representation
Resource Type Dataset
Discipline Marine Science