Figure 1.
The study area with experimental station locations (corresponding to Table 1).
Table 1.
Experimental dates and conditions.
Table 2.
Published relationships between plankton growth rates (µ, d−1), temperature (T, °C), and cell volume (V, µm3) unless noted otherwise.
Figure 2.
Common microzooplankton from the Barents Sea: (a) Parafavella gigantea, 250 µm (insert shows a mitotic cell stained with DAPI); (b) Leprotintinnus pellucidus, 300 µm; (c) cytokinetic Strombidium sp. 40 µm; (d) Gyrodinium spirale 120 µm; (e) cytokinetic Lohmaniella oviformis 22 µm, OP = oral primordium; (f) Amphidinium sphenoides 35 µm; (g) Mesodinium rubrum 35 µm; (h) Strombidium constrictum 40 µm; (i) Ceratium arcticum 200 µm; (j) Strombidium conicum 75 µm; (k) Dinophysis norvegica 65 µm.
Images are not to scale. (a–h) Lugol’s-fixed cells under DIC; (i–k) DAPI and Chl autofluorescence.
Table 3.
Growth rates and volumes of common microzooplankton species in the Barents Sea.
Figure 3.
Microzooplankton growth rates within taxonomic orders across a temperature gradient.
Figure 4.
The relationship between the initial abundance and growth rates of microzooplankton species in bottle experiments.
Figure 5.
Comparison of the average observed and predicted growth rates.
The equations used for growth rate calculations are presented in Table 2. Open bars indicate observed rates, striped bars indicate calculated rates corrected using Q10 = 2.8, dotted bars show Q10 = 1.58.
Figure 6.
Differences between observed species-specific and predicted growth rates of ciliates and dinoflagellates across a temperature gradient.
Predicted rates were calculated based on equations from Nielsen and Kiørboe [37], [45], Perez et al. [39], and Tang [41] for ciliates >20 µm, ciliates <20 µm, and phytoplankton, respectively.
Figure 7.
Average differences between observed species-specific and predicted growth rates from Figure 5 separated into microzooplankton functional-taxonomic groups (A) and size-taxonomic groups (B).
HCIL = heterotrophic ciliates, HDIN = heterotrophic dinoflagellates, MCIL = mixotrophic ciliates, MDIN = mixotrophic ciliates, MRUB = Mesodinium rubrum.
Figure 8.
Observed species-specific growth rates of microzooplankton at temperatures below 5°C and predicted temperature-dependent growth rates of phytoplankton and herbivorous microzooplankton based on published equations from Table 2.