Table 1.
Daily fluctuation of the seawater carbonate speciation in the two experimental CO2 levels (360 and 700 ppm). Values of total carbon (TC), bicarbonate (HCO3−), and carbonate (CO32−) were calculated using total alkalinity (TA), pH, salinity, and temperature of the seawater (Pelletier et al. 1997). Values are mean ± SD (n = 6) and represent pooled data from the two replicate mesocosm units. Units are μmol/Kg
| 360 ppm | 700 ppm | |||||||
|---|---|---|---|---|---|---|---|---|
| Daytime (h) | TA | TC | HCO3− | CO32− | TA | TC | HCO3− | CO32− |
| 04:00 | 2722 ± 17 | 2340 ± 16 | 2040 ± 15 | 285 ± 3 | 2760 ± 18 | 2510 ± 17 | 2288 ± 16 | 198 ± 2 |
| 06:00 | 2629 ± 34 | 2278 ± 40 | 2015 ± 36 | 255 ± 3 | 2765 ± 14 | 2529 ± 13 | 2314 ± 12 | 190 ± 2 |
| 08:00 | 2656 ± 21 | 2295 ± 13 | 2032 ± 19 | 259 ± 2 | 2738 ± 24 | 2488 ± 20 | 2266 ± 20 | 198 ± 7 |
| 10:00 | 2661 ± 19 | 2260 ± 39 | 1926 ± 54 | 305 ± 17 | 2697 ± 10 | 2398 ± 9 | 2153 ± 17 | 227 ± 10 |
| 12:00 | 2653 ± 9 | 2121 ± 24 | 1730 ± 36 | 376 ± 16 | 2697 ± 15 | 2300 ± 22 | 2001 ± 26 | 286 ± 7 |
| 14:00 | 2622 ± 14 | 2035 ± 12 | 1613 ± 20 | 411 ± 6 | 2660 ± 16 | 2277 ± 24 | 1986 ± 35 | 277 ± 15 |
| 16:00 | 2627 ± 15 | 2028 ± 29 | 1582 ± 45 | 428 ± 14 | 2680 ± 14 | 2307 ± 13 | 2020 ± 13 | 273 ± 5 |
| 19:30 | 2702 ± 25 | 2145 ± 20 | 1695 ± 57 | 400 ± 18 | 2743 ± 29 | 2409 ± 26 | 2141 ± 24 | 251 ± 6 |
| 00:00 | 2743 ± 15 | 2238 ± 4 | 1878 ± 17 | 360 ± 5 | 2774 ± 42 | 2456 ± 39 | 2192 ± 35 | 244 ± 4 |