TABLE 1.
Fluxes of oxygen and calcium (mean ± standard error; n = 2) and pH changes at biofilm surfaces measured in samples from the Deinschwanger Bacha
| Site | pH
|
Flux (mol m−2 s−1)
|
ΔpH
|
|||||
|---|---|---|---|---|---|---|---|---|
| O2
|
Ca2+
|
|||||||
| Experimental | Initial | Light | Dark | Light | Dark | Light | Dark | |
| 1 | 7.8 | 7.8 | 1.7 × 10−6 ± 7.1 × 10−8* | −2.4 × 10−7 ± 2.3 × 10−9* | −1.2 × 10−6 ± 2.5 × 10−8* | 0* | 0.86 | −0.04 |
| 8.4 | 8.4 | 4.4 × 10−6 ± 1.4 × 10−6* | −3.8 × 10−7 ± 1.4 × 10−7* | −1.3 × 10−6 ± 1.5 × 10−8* | 1.2 × 10−7 ± 1.3 × 10−8** | 0.54 | −0.36 | |
| 8.9 | 8.9 | 1.1 × 10−6 ± 2.1 × 10−7* | −1.4 × 10−7 ± 1.0 × 10−8* | −1.4 × 10−6 ± 8.5 × 10−8* | −5.1 × 10−7 ± 6.1 × 10−8** | 0.07 | −0.66 | |
| 2 | 7.8 | 7.6 | 8.0 × 10−7 ± 1.3 × 10−8* | −1.5 × 10−7 ± 3.0 × 10−8* | −1.1 × 10−6 ± 6.0 × 10−8* | 3.3 × 10−7 ± 7.1 × 10−8* | 1.75 | 0.2 |
| 8.4 | 8.4 | 1.6 × 10−6 ± 7.5 × 10−8* | −4.3 × 10−7 ± 9.1 × 10−8* | −8.9 × 10−7 ± 5.4 × 10−8* | 0* | 0.62 | −0.48 | |
| 8.9 | 8.9 | 6.4 × 10−7 ± 8.5 × 10−8* | −2.4 × 10−7 ± 1.0 × 10−8* | −7.9 × 10−7 ± 4.6 × 10−8** | −1.7 × 10−7 ± 7.3 × 10−8* | 0.67 | −0.85 | |
a
For fluxes, positive values indicate flux from the biofilm to the water column, and negative values indicate the opposite. Values with the same number of asterisks (within each chemical and light phase at each site) were not significantly different (P > 0.05).