Table 1.
Carbonate chemistry.
Table 2.
Initial composition and abundance of phytoplankton and microzooplankton.
Figure 1.
Euphausia superba ingestion rates.
Chlorophyll a and ciliate carbon ingestion rates of krill exposed to ambient (Amb) and high ( = 672 ppm) concentrations of CO2. Chlorophyll a was converted to C using a C:chl ratio of 63∶1 estimated in our study area by Bernard et al. [74]. Ingestion rates of krill on ciliates were converted to C using cell C to volume conversions from Putt and Stoecker [76]. Mean of n = 5 for non-gravid and gravid krill and n = 10 for all krill; error bars = 2×standard error. x and y denote a significant difference in total C ingestion rates between treatments (x>y, p<0.05).
Figure 2.
Euphausia superba organic and inorganic nutrient release rates.
Dissolved organic carbon (DOC; a), ammonium (NH4+; b), phosphate (PO43−; c), and urea (d) release rates of krill exposed to ambient and high ( = 672 ppm) concentrations of CO2. Mean of n = 5 for non-gravid and gravid krill and n = 10 for all krill; error bars = 2×standard error. For DOC release, x and y denote a significant difference between treatments (x>y, p<0.05).
Figure 3.
Euphausia superba chemical composition.
Chemical composition (a: % carbon, %C; b: % nitrogen, %N; c: C:N molar ratio; d: % particulate organic carbon, % POC; and e: % particulate inorganic carbon, % PIC) of krill exposed to ambient and high ( = 672 ppm) concentrations of CO2. Mean of n = 4 for non-gravid and gravid krill and n = 8 for all krill; error bars = 2×standard error. v, w, x, and y denote significant differences between treatments (v>w>x>y, p<0.05).
Table 3.
Physical and chemical characteristics of Euphausia superba.
Figure 4.
Euphausia superba metabolic enzyme activity and protein content.
Malate dehydrogenase activity (MDH; a), lactate dehydrogenase activity (LDH; b), and protein (c) of krill exposed to ambient and high ( = 672 ppm) concentrations of CO2. Mean of n = 3 for non-gravid and gravid krill and n = 6 for all krill; error bars = 2 × standard error.