Table 3. Physical conditions, sizes of oysters, and mortality in 2009 and 2010 laboratory experiments [X ± SE (n)].
| 40 L aquaria, 1 year-old oysters | 80L aquaria, 2 and 3 year-old oysters | |||||
|---|---|---|---|---|---|---|
| Control | 1.5 mg l-1 | 0.5 mg l-1 | Control | 1.5 mg l-1 | 0.5 mg l-1 | |
| 2009 | ||||||
| Daily maximum DO (mg l-1) | 7.30±0.03 (265) | 6.52±0.07 (265) | 6.61±0.08 (266) | 7.18±0.03 (265) | 6.46±0.07 (265) | 6.28±0.08 (265) |
| Daily minimum DO (mg l-1) | 6.68±0.07 (265) | 1.46±0.02 (265) | 0.66±0.08 (265) | 6.48±0.08 (265) | 1.63±0.02 (265) | 0.78±0.01 (265) |
| Temperature (°C) | 25.0±0.1 (285) | 25.0±0.1 (285) | 25.0±0.1 (285) | 25.2±0.2 (285) | 25.3±0.2 (285) | 25.3±0.2 (285) |
| pH | 7.52±0.02 (65) | 7.44±0.01 (65) | 7.52±0.02 (65) | 7.48±0.02 (65) | 7.40±0.02 (65) | 7.44±0.02 (65) |
| Salinity | 11.3±0.1 (186) | 11.2±0.1 (196) | 11.3±0.1 (187) | 11.3±0.1 (188) | 11.2±0.09 (196) | 11.2±0.04 (197) |
| Starting shell height (mm) | 50.5±0.4 (275) | 51.4±0.4 (275) | 50.2±0.4 (275) | 76.6±0.6 (275) | 76.8±0.7 (275) | 77.5±0.8 (275) |
| Ending shell height (mm) | 54.7±0.8 (102) | 53.7±0.7 (108) | 53.9±0.7 (100) | 73.1±0.9 (97) | 73.0±1.0 (108) | 73.7±1.2 (94) |
| Total mortality (%) | 10.9±3.7 (5) | 10.9±4.5 (5) | 9.1±3.8 (5) | 12.4±1.0 (5) | 8.7±1.8 (5) | 9.5±1.1 (5) |
| 2010 | ||||||
| Daily maximum DO (mg l-1) | 7.53±0.02 (321) | 6.91±0.03 (321) | 6.89±0.04 (321) | 7.35±0.03 (320) | 6.54±0.06 (320) | 6.65±0.05 (320) |
| Daily minimum DO (mg l-1) | 7.16±0.02 (321) | 1.47±0.03 (321) | 0.50±0.01 (321) | 7.00±0.03 (321) | 1.53±0.02 (320) | 0.64±0.01 (320) |
| Temperature (°C) | 26.0±0.11 (268) | 26.0±0.11 (273) | 26.1±0.11 (269) | 26.5±0.12 (271) | 26.4±0.13 (279) | 26.5±0.12 (267) |
| pH | 7.79±0.03 (20) | 7.82±0.03 (20) | 7.96±0.03 (20) | 7.71±0.03 (20) | 7.76±0.03 (20) | 7.94±0.03 (20) |
| Salinity | 11.8±0.1 (247) | 11.8±0.1 (247) | 11.8±0.1 (245) | 11.8±0.1 (248) | 11.8±0.1 (259) | 11.8±0.1 (248) |
| Starting shell height (mm) | 46.4±0.4 (450) | 45.8±0.4 (450) | 45.5±0.4 (450) | 78.9±0.3 (450) | 78.5±0.3 (450) | 78.6±0.3 (450) |
| Ending shell height (mm) | 46.2 ±0.4 (267) | 45.2 ±0.4 (277) | 44.4 ±0.4 (272) | 79.2±0.5 (194) | 77.9±0.5 (203) | 79.1±0.5 (216) |
| Ending tissue wet weight (g) | 1.07±0.04 (150) | 0.92±0.04 (150) | 0.93±0.05 (150) | 5.84±0.14 (150) | 5.15±0.14 (150) | 6.09±0.05 (150) |
| Total mortality (%) | 6.2±1.3 (5) | 7.2±3.3 (5) | 7.1±1.8 (5) | 24.2±1.6 (5) | 21.1±0.9 (5) | 18.4±1.7 (5) |
Means were calculated from daily mean, minimum or maximum values of replicate measurements within each aquarium averaged over all dates on which DO concentrations were manipulated. Because of low variation among aquaria of similar sizes, temperature and salinity were not always measured in all aquaria each day. In 2010, pH was measured in all tanks near the end of the low plateau period on 4 dates.