Table 3 Photophysiological responses.

From: Iron and manganese co-limit the growth of two phytoplankton groups dominant at two locations of the Drake Passage

 

Fv/Fm

σPSII

τQA

P

 

rel. unit

nm2

μs

rel. unit

West

 Initial

0.21 ± 0.02

5.61

588

0.25

 Control

0.26 ± 0.04c

4.46 ± 1.00a

470 ± 58a

0.13 ± 0.05c

 +Mn

0.25 ± 0.04c

4.20 ± 0.73a

536 ± 57a

0.18 ± 0.06c

 +Fe

0.44 ± 0.05b

4.26 ± 1.51a

643 ± 11a

0.36 ± 0.06b

 +FeMn

0.51 ± 0.04a

2.80 ± 1.24b

721 ± 60b

0.35 ± 0.03a

East

 Initial

0.18 ± 0.03

4.68

290

0.10

 Control

0.25 ± 0.07c

3.42 ± 1.15b

669 ± 280b

0.21 ± 0.01c

 +Mn

0.27 ± 0.01c

4.68 ± 0.52a

598 ± 46a

0.24 ± 0.02c

 +Fe

0.43 ± 0.05b

3.22 ± 1.52b

711 ± 66b

0.36 ± 0.02b

 +FeMn

0.47 ± 0.02a

3.41 ± 1.16b

718 ± 23b

0.37 ± 0.01a

  1. The dark-adapted maximum photosystem II quantum yield (Fv/Fm), the functional absorption cross-section of PSII (σPSII), the time constant for electron transfer at PSII (τQA) and the connectivity between adjacent photosystems (P) were determined at the start and the end of the experiment from the communities sampled West and East after exposure to different Fe and Mn availabilities. Values represent the mean ± SD (n > 10). Different letters indicate significant differences between treatments (p < 0.05).