Table 1. Growth of prey organisms at DCM and surface conditions.

Depth, m	DOC, mg C liter-1	PAR, μmol m-2·s-1	Temperature, °C	μ phototrophs, d-1	μ bacteria, d-1
2.5	1.3	60	17.0	0.60 ± 0.06	1.05 ± 0.05
2.5	0.8	60	22.1	0.60 ± 0.03	1.01 ± 0.06
3.6	0.9	20	16.4	-0.02 ± 0.03	0.34 ± 0.06
6.0	3.7	7	10.3	0.05 ± 0.01	0.15 ± 0.01
8.5	2.9	2	7.8	-0.01 ± 0.01	0.13 ± 0.02

Growth rates of separate cultures of natural bacterioplankton and phototrophs (Chlamydomonas) (μ ± SE). We used sterile filtered Lake 111 water from different depths. The PAR denotes that applied in the laboratory. In situ PAR values can be estimated on the basis of continuous solar radiation measurements at Lake 111 and light attenuation with depth (24). PAR was calculated as 58, 23, 3.1, and 0.4 μmol photons m^-2·s^-1 at 2.5, 2.5, 3.6, 6.0, and 8.5 m, respectively, over a mean 16 h, per day from May to August 1999. DOC, dissolved organic carbon.