Table 1.
Experimental conditions in dilute batch culture incubations (see also Eberlein et al., 2014, Hoins et al., 2015): average CO2 concentrations (μmol L− 1), total alkalinity (TA; μmol L− 1), dissolved inorganic carbon (DIC; μmol L− 1) and pH (NBS scale). HCO3− contribution, leakage, modeled carbon isotope fractionation (εp-mod) and measured carbon isotope fractionation (εp-meas) was derived under the same conditions.
| pCO2 μatm | CO2 μmol L− 1 | TA μmol L− 1 | DIC μmol L− 1 | pH NBS | HCO3− contribution | Leakage | εp-mod ‰ | εp-meas ‰ |
|---|---|---|---|---|---|---|---|---|
| A. fundyense | ||||||||
| 180 | 5.9 ± 0.9a | 2434 ± 3 | 1992 ± 10a | 8.50 ± 0.06a | 0.22 ± 0.03 | 0.44 ± 0.01a | 10.1 ± 0.2a | 9.0 ± 0.3a |
| 380 | 11.5 ± 2.1b | 2439 ± 1 | 2117 ± 8b | 8.27 ± 0.07b | 0.24 ± 0.04 | 0.46 ± 0.02a | 10.6 ± 0.5a | 10.2 ± 0.5b |
| 800 | 25.9 ± 5.8c | 2434 ± 2 | 2245 ± 8c | 7.97 ± 0.10c | 0.24 ± 0.04 | 0.53 ± 0.02b | 12.6 ± 0.6b | 12.7 ± 0.4c |
| 1200 | 36.5 ± 9.3d | 2418 ± 1 | 2283 ± 5d | 7.83 ± 0.12d | 0.23 ± 0.08 | 0.63 ± 0.05c | 15.3 ± 0.8c | 12.1 ± 0.2c |
| S. trochoidea | ||||||||
| 180 | 6.6 ± 0.2a | 2386 ± 1 | 1872 ± 2a | 8.45 ± 0.01a | 0.53 ± 0.03a,b | 0.56 ± 0.06 | 10.4 ± 1.5 | 6.0 ± 0.5a,b |
| 380 | 13.1 ± 0.5b | 2388 ± 2 | 2096 ± 3b | 8.21 ± 0.02b | 0.55 ± 0.04a | 0.53 ± 0.06 | 9.4 ± 1.5 | 5.0 ± 0.1a |
| 800 | 28.8 ± 2.0c | 2385 ± 1 | 2223 ± 3c | 7.91 ± 0.03c | 0.48 ± 0.03b,c | 0.54 ± 0.01 | 10.3 ± 0.5 | 7.1 ± 0.7b |
| 1200 | 41.5 ± 3.6d | 2386 ± 4 | 2268 ± 9d | 7.77 ± 0.04d | 0.46 ± 0.04c | 0.48 ± 0.04 | 8.8 ± 1.1 | 11.8 ± 0.7c |
| G. spinifera | ||||||||
| 180 | 6.0 ± 1.1a | 2447 ± 5 | 1962 ± 15a | 8.50 ± 0.05a | 0.19 ± 0.11 | 0.61 ± 0.01 | 15.6 ± 0.9a | 7.8 ± 1.0a |
| 380 | 11.7 ± 2.5b | 2461 ± 12 | 2083 ± 1b | 8.27 ± 0.07b | – | – | – | 9.4 ± 0.4a |
| 800 | 27.9 ± 7.4c | 2475 ± 13 | 2224 ± 9c | 7.96 ± 0.10c | 0.19 ± 0.11 | 0.71 ± 0.01 | 18.6 ± 1.7b | 11.7 ± 0.7b |
| 1200 | 42.4 ± 7.9d | 2459 ± 4 | 2293 ± 5d | 7.78 ± 0.06d | – | – | – | 8.1 ± 0.5a |
| P. reticulatum | ||||||||
| 180 | 7.1 ± 0.5a | 2460 ± 8 | 2002 ± 2a | 8.43 ± 0.04a | 0.44 ± 0.13 | 0.50 ± 0.06 | 9.58 ± 2.0 | 8.4 ± 1.8 |
| 380 | 13.9 ± 0.8b | 2455 ± 2 | 2121 ± 4b | 8.21 ± 0.02b | – | – | – | 8.4 ± 0.7 |
| 800 | 31.0 ± 4.7c | 2461 ± 12 | 2249 ± 23c | 7.88 ± 0.08c | 0.49 ± 0.19 | 0.48 ± 0.09 | 9.2 ± 1.9 | 8.6 ± 2.0 |
| 1200 | 45.2 ± 6.9d | 2473 ± 19 | 2288 ± 16d | 7.75 ± 0.05d | – | – | – | 9.9 ± 0.8 |
Values represent the mean of triplicate incubations (n = 3; ± SD). Superscript letters indicate significant differences between pCO2 treatments (P < 0.05).