The photosynthetic and respiratoric capacity of Fucus vesiculosus grown at three different levels of salinity (4.5, 8 and 20‰) was studied in the presence of different concentrations of lead (5, 10, 15, 20, 25, and 30 mg PbCl2 L−1). The studies were performed by using a light-pipette, which has a precisely defined light source of photosynthetic active radiation (PAR, 400–700 nm). The photosynthetic and respiratoric capacity of the algae were measured when exposed to light pulses with increasing irradiance and after 24 hr in seawater with the addition of lead. The results indicate that the photosynthetic capacity of F. visiculosus from 20‰ is more sensitive to lead compared to those from 8 and 4.5‰. The photosynthetic capacity was reduced by 69% at 30 mg PbCl2 L−1 compared to the control alga. The photosynthetic capacity of F. vesiculosus from 8 and 4.5‰ was reduced by 38 and 15%. The respiratoric capacity of F. vesiculosus from 20‰ was reduced by 41% at 30 mg PbCl2 L−1. However, the respiratoric capacity of the algae from 4.5‰ increased by 55% at the same concentration of PbCl2. The results indicate that lead showed inhibitory effects on photosynthesis but a stimulatory effect on respiration of F. versiculosus grown at low levels of salinity.