Table 3. Comparison of control pCO₂ treatments of M. edulis growth trials conducted in our laboratory.

Experiment	S	T	Ωarag	kinematic viscosity	calculated filtration rate	cell density(aquaria)	shell lengthgrowth
	g kg−1	°C	control	10−6 m2 s−1	ml min−1	n ml−1	% initial
Thomsen et al. (2010)summer 2009	15.0±0.6	13.8±0.6	1.14±0.04	1.19±0.019	9.2	820±315	64.8±3.8
Thomsen and Melzner (2010)autumn 2009	18.1±1.0	9.1±0.4	1.11±0.12	1.36±0.017	7.6	2330±482	53.0±2.0
this study HFwinter 2010	16.0±1.3	4.9±0.7	0.72±0.03	1.53±0.003	6.0	1734±167	15.2±7.3
this study LFwinter 2010	16.0±1.3	5.4±0.6	0.73±0.07	1.51±0.009	6.1	336±16	7.0±1.8

The summer and autumn experiments lasted 8 weeks [10], [15], the present winter experiment 7 weeks. Filtration rates were calculated for a standard 18 mm mussel (see methods) to illustrate the impact of temperature dependent changes in seawater viscosity. As M. edulis has a retention rate of ca. 100% for particles with a diameter >4 µm, reduced filtration rates at low temperatures directly translate into reduced energy uptake, even if aquarium algae concentrations are similar. See Methods for calculation of filtration rates in response to seawater viscosity. Means and standard deviations (in brackets). Shell length growth corresponds to growth during the entire experimental period of the respective experiments. Cell density refers to the average Rhodomonas cell density in the experimental aquaria. Ω_arag refers to the aragonite saturation states in the experimental aquaria.