Benthic primary producers are key to sustain the Wadden Sea food web: stable carbon isotope analysis at landscape scale
Christianen, M.J.A.; Middelburg, J.J.; Holthuijsen, S.J.; Jouta, J.; Compton, T.J.; van der Heide, T.; Piersma, T.; Sinninghe Damsté, J.S.; van der Veer, H.W.; Schouten, S.; Olff, H. (2017). Benthic primary producers are key to sustain the Wadden Sea food web: stable carbon isotope analysis at landscape scale. Ecology 98(6): 1498-1512. https://dx.doi.org/10.1002/ecy.1837 In: Ecology. Ecological Society of America: Brooklyn, NY. ISSN 0012-9658; e-ISSN 1939-9170, more |   |
| Author keywords | carbon subsidy; coastal food web; Dutch Wadden Sea; estuary; macrobenthos; stable carbon isotopes; tidal wetland ecosystem |
| Authors | | Top | - Christianen, M.J.A.
- Middelburg, J.J., more
- Holthuijsen, S.J., more
- Jouta, J., more
| - Compton, T.J., more
- van der Heide, T.
- Piersma, T., more
- Sinninghe Damsté, J.S., more
| - van der Veer, H.W., more
- Schouten, S., more
- Olff, H.
|
| Abstract | Coastal food webs can be supported by local benthic or pelagic primary produc-ers and by the import of organic matter. Distinguishing between these energy sources is essen-tial for our understanding of ecosystem functioning. However, the relative contribution ofthese components to the food web at the landscape scale is often unclear, as many studies lackgood taxonomic and spatial resolution across large areas. Here, using stable carbon isotopes,we report on the primary carbon sources for consumers and their spatial variability across oneof the world’s largest intertidal ecosystems (Dutch Wadden Sea; 1460 km2intertidal surfacearea), at an exceptionally high taxonomic (178 species) and spatial resolution (9,165 samplesfrom 839 locations). The absence of overlap in d13C values between consumers and terrestrialorganic matter suggests that benthic and pelagic producers dominate carbon input into thisfood web. In combination with the consistent enrichment of benthic primary producers(d13C 16.3&) relative to pelagic primary producers (d13C 18.8) across the landscape, thisallowed the use of a two-food-source isotope-mixing model. This spatially resolved modellingrevealed that benthic primary producers (microphytobenthos) are the most important energysource for the majority of consumers at higher trophic levels (worms, molluscs, crustaceans,fish, and birds), and thus to the whole food web. In addition, we found large spatial hetero-geneity in the d13C values of benthic primary producers (d13C 19.2 to 11.5&) and primaryconsumers (d13C 25.5 to 9.9&), emphasizing the need for spatially explicit sampling of ben-thic and pelagic primary producers in coastal ecosystems. Our findings have important impli-cations for our understanding of the functioning of ecological networks and for themanagement of coastal ecosystems. |
|
