Table 2. Results of pooled growth and photosynthetic parameters in response to treatment conditions.

The results of independent t-tests to analyze the effect of CO₂ enrichment on response variables for each species. Responses of species used in multiple experiments (different years) were pooled and averaged across years by treatment to calculate an overall mean for each species. CO₂ treatment was treated as a fixed, independent factor. Degrees of freedom (df) are the same for all photosynthetic parameters. Each experimental replicate (n) consisted of one aquarium containing one algal individual. Statistically significant differences (p < 0.05) are emphasized in bold.

	Growth			rETRMax			α		β
Species	df	t	p	df	t	p	t	p	t	p
Fleshy macroalgae
A. spicifera	10	1.15	0.275	9	2.55	0.031	0.341	0.741	0.088	0.932
A. amadelpha	18	3.12	0.006
C. serrulata	22	0.066	0.948	19	0.282	0.781	0.350	0.730	0.356	0.726
D. bartayresiana	8	2.13	0.066	8	1.55	0.159	0.274	0.791	1.14	0.292
H. pannosa	5	4.90	0.004	5	0.186	0.556	0.602	0.60	0.624	0.560
Upright calcareous algae
D. marginata	8	3.83	0.005	8	0.440	0.83	0.092	0.929	0.823	0.434
G. rugosa	10	1.63	0.134	10	4.10	0.002	1.71	0.118	0.760	0.465
H. opuntia	16	2.59	0.020	16	0.046	0.964	1.43	0.171	0.223	0.827
H. taenicola	38	0.21	0.832	18	0.193	0.849	2.23	0.039	1.62	0.123
Crustose coralline algae
Lithophyllum sp.	16	5.28	<0.0001	16	0.582	0.569	0.280	0.783	1.0	0.332
L. prototypum	6	2.79	0.032	6	0.357	0.733	0.404	0.700