Table 1. Estimated fluxes (mmol C m−2 h−1), light (μmol photons m−2 s−1) and temperature (°C) for sediment with BCMs (BCM), after experimental removal (CTRL 1), and for sediment without BCM (CTRL 2). Flux calculations are based on 6 h except for O2 and DIC due to flux changes in the last hours caused by high concentrations. DOC fluxes are not available for CTRL 2 due to a shortage of sample containers. Differences among treatments from each day and night period were analysed by one-way ANOVA (Significance <0.05, ns = non significant). Significance column indicates homogeneous subgroups by posthoc Scheffé tests. n.s. = not significant. na = data not available.
| Treatment: | BCM | CTRL 1 | CTRL 2 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Significance | ||||
| DAY | ||||||||||
| O2 | 8.77 | ± | 0.86 | 0.99 | ± | 0.41 | 1.29 | ± | 0.43 | BCM > CTRL1 = CTRL2 |
| DIC | −12.10 | ± | 1.16 | −1.94 | ± | 1.26 | −1.88 | ± | 1.56 | BCM > CTRL1 = CTRL2 |
| DOC | 1.36 | ± | 1.21 | −0.85 | ± | 0.67 | na | ± | na | BCM > CTRL1 |
| Light | 193.8 | ± | 49.0 | 245.6 | ± | 16.2 | 163.6 | ± | 5.7 | n.s. |
| Temperature | 29.9 | ± | 0.3 | 30.1 | ± | 0.2 | 29.7 | ± | 0.3 | BCM = CTRL1 > CTRL2 |
| Error (%)a | 4.4–8.7 | ± | 2.9–5.8 | 5.2–10.5 | ± | 2.6–5.2 | 4.5–9.0 | ± | 3.3–6.6 | |
| NIGHT | ||||||||||
| O2 | −3.25 | ± | 0.81 | −1.14 | ± | 0.73 | −1.39 | ± | 0.36 | BCM > CTRL1 = CTRL2 |
| DIC | 8.75 | ± | 2.60 | 2.24 | ± | 1.16 | 2.44 | ± | 2.30 | BCM > CTRL1 = CTRL2 |
| DOC | 3.52 | ± | 2.03 | −0.64 | ± | 0.69 | na | ± | na | BCM > CTRL1 |
| Temperature | 29.3 | ± | 0.3 | 29.3 | ± | 0.3 | 28.9 | ± | 0.2 | BCM = CTRL1 > CTRL2 |
| Error (%)a | 4.5–9.0 | ± | 3.4–6.7 | 6.6–13.1 | ± | 3.3–6.6 | 4.6–9.2 | ± | 3.8–7.6 | |
aError estimates for flux data.