Table 1. N flux across the nutricline calculated from video plankton recorder (VPR) and diver-based observations made during 2003.
Flux calculations assumed 0.19 and 2.5 µmol N mat-1 (Villareal et al., 1999b) for small and large mats, respectively, and a specific rate increase of 0.14 d-1 (Richardson et al., 1998) Diver and VPR estimates are added due to the non-overlapping nature of the abundance estimates. These estimates are supplemented with contributions to upward nitrate flux from other (non-Rhizosolenia mat) migrating phytoplankton. Doubling time reflects the time required to migrate to depth, acquire nutrients, return to the surface and divide and is based on direct measurement or best available information (citations may be found in the text section on the individual taxon).
| Rhizosolenia mats | |||||
|---|---|---|---|---|---|
| Integrated mats (mats m−2) | Sta. 5 | Sta. 6 | Sta. 7 | Sta. 12a | Sta. 12b |
| Divers (0–20 m) | 26 | 3 | 3 | 6 | 6.4 |
| VPR (0–20 m) | 188 | 38 | 3938 | 38 | 300 |
| VPR (0–150 m) | 2,475 | 188 | 6,562 | 17,062 | 16,612 |
| VPR:Diver (0–20) | 7 | 13 | 1313 | 6 | 47 |
| N flux (µmol N m-2 d-1) | |||||
| Diver-based N flux | 8.9 | 1 | 1 | 2 | 2 |
| VPR-based N flux | 64 | 5 | 170 | 442 | 430 |
| TOTAL (Diver + VPR) | 73 | 6 | 171 | 444 | 432 |