Semipermeable membrane-based passive samplers were located in 3 places in the Gdansk Gulf to monitoring in situ the concns. of persistent org. pollutants (POP) in the sea water for 28 days in spring and autumn 2002-2005. The samplers consisted of low-d. polyethylene layflat tubing filled with triolein. The POP were removed from the samplers by dialysis to hexane and analyzed by the capillary gas chromatog. for the chem. compn. The samplers contained mainly fluoranthene (up to 100.8 ng/L), phenanthrene (up to 99.4 ng/g) and benzoanthracene (up to 94.2 ng/g).