Figure 7.

Dark vs. light bacterial activity measurements. Comparison between bulk ³H-leucine incorporation rates in different light conditions and dark incubations conducted with surface seawater samples (<5 m) from different systems and with the radiotracer added before exposure. Exposure to simulated PAR caused an average 23% stimulation while PAR+UVR led to an average 20% inhibition in comparison to the dark controls (see text). Mediterranean data from Ruiz-González et al. (2012e); Bay of Biscay (Calvo-Díaz, 2008); Delaware Bay (Straza and Kirchman, 2011); N Atlantic (Michelou et al., 2007); E Pacific (Pakulski et al., 2007); Arctic and Antarctica (Ruiz-González et al., 2012a and unpublished).