Table 2. Community net O₂ production and community dark respiration in Trichodesmium colonies, based on microsensor measurements performed under different pCO₂ levels (ambient vs high pCO₂; mean±s.d.).

pCO2	Net O2 production		Dark respiration
	nmol O2 colony−1 h−1	nmol O2 mm−3 h−1	nmol O2 colony−1 h−1	nmol O2 mm−3 h−1
Ambient
Mean±s.d.	1.5±0.9 (n=10)	20±12 (n=10)	0.7± 0.4 (n=10)	7±4 (n=7)
Range	0.4–3.1	3–41	0.3–1.2	2–14
High
Mean±s.d.	1.5±1.7 (n=4)	11±10 (n=4)	2.0±1.9 (n=3)	7±4 (n=3)
Range	0.2–3.9	4–25	0.4–4.1	3–10

Abbreviations: O_2, oxygen; pCO₂, partial pressure of carbon dioxide.

Volumetric rates are normalized to colony volume.