Fig. 3.

Uptake of cyanobacteria-fixed nitrogen by pelagic and benthic consumers inferred from seasonal changes in their δ ¹⁵N values and stomach content analysis in relation to the cyanobacterial bloom in different areas of the Baltic Sea. a δ ¹⁵N (mean ± SD) in invertebrates and fish from three coastal areas: Åland Islands (Nordström et al. 2009), Curonian Lagoon (Lesutiene et al. 2014), and Askö area (Rolff 2000), in relation to the cyanobacteria bloom. Invertebrate species and groups: Cr Crangon crangon; Ne Nereis diversicolor; Ma Macoma balthica; Ba Bathyporeia pilosa; Ch Chironomidae; Dr Dreissena polymorpha; Va Valvata; Ol Oligochaeta; Mz mesozooplankton; PL4 zooplankton, size 100–200 µm (nauplii, rotifers, ciliates); PL5 zooplankton, size 200–500 µm (copepodites, cladocerans); and PL6 zooplankton, size > 500 µm (adult copepods). Fish: Pl Platichthys flesus and Ga Gasterosteus aculeatus; b δ ¹⁵N values of zooplankton (bars, primary Y-axis on the left side; mean ± SD, n > 3) and grazing on cyanobacteria derived from qPCR-based estimates of N. spumigena abundance in zooplankton stomachs (circles; secondary Y-axis on the left side; mean ± SD, n > 4) sampled throughout cyanobacteria bloom (green line) in the open sea (Landsort Deep, station BY31; year 2011; Motwani 2015; see Appendix S3). c δ ¹⁵N values in deposit-feeders (mean ± SD, n > 10) sampled before and after a cyanobacteria bloom (green line) in a coastal area (Askö, station B1; year 2010; modified from Karlson et al. (2014)