TY - SER ID - cazzanelli2012acme T1 - Absorption characteristics, major elements and chl a content of samples from Pond 19 at Zackenberg, NE Greenland AU - Cazzanelli, Matteo AU - Forsström, Laura AU - Rautio, Milla AU - Michelsen, Anders AU - Christoffersen, Kirsten Seestern PY - 2012 T2 - Supplement to: Cazzanelli, M et al. (2012): Benthic resources are the key to Daphnia middendorffiana survival in a high arctic pond. Freshwater Biology, 57(3), 541-551, https://doi.org/10.1111/j.1365-2427.2011.02722.x PB - PANGAEA DO - 10.1594/PANGAEA.808244 UR - https://doi.org/10.1594/PANGAEA.808244 N2 - 1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic-pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitrogen in the pond itself and in a 13C-enrichment enclosure experiment. In the latter, we manipulated the carbon isotope signature of benthic algae to enhance its isotopic discrimination from other potential food sources for zooplankton. 2. The cladoceran Daphnia middendorffiana responded to the 13C-enrichment of benthic mats with progressively increasing d13C values, suggesting benthic feeding. Stable isotope analysis also pointed towards a negligible contribution of terrestrial carbon to the diet of D. middendorffiana. This agreed with the apparent dominance of autochthonous dissolved organic matter in the pond revealed by analysis of coloured dissolved organic matter. 3. Daily net production by phytoplankton in the pond (18 mg C/m**2/day) could satisfy only up to half of the calculated minimum energy requirements of D. middendorffiana (35 mg C/m**2/day), whereas benthic primary production alone (145 mg C/m**2/day) was more than sufficient. 4. Our findings highlight benthic primary production as a major dietary source for D. middendorffiana in this system and suggest that benthic organic matter may play a key role in sustaining pelagic secondary production in such nutrient-limited high arctic ponds. ER -