An air breathing supralittoral amphipod Talitrus saltator (Montagu, 1808) is common on sandy beaches along Atlantic coast of Europe and the Mediterranean. During last 50 years it has become rare on most sandy beaches of the East and South-east Baltic. For example, it occurs in an area of some 2 to 5 sq.km along a 500-km-long stretch of sandy coast [1]. This crustacean due to its size up to 15-18 mm is regarded as macrofauna. With its mouth parts and digestive system it feeds on decaying algae which are washed out of the sea, and so, plays a primary role in the process of decomposition of organic matter on the beach. The entire sandy beach ecosystem including meofauna is an important component of artificial beaches that are used for water improvement.As a nocturnal animal sand-hopper stays in the sand during the day at the depth 5-20 cm and appears at the surface of the beach at the sun set. During its vertical migrations in the sand T.saltator changes its structure.The aim of the study is to estimate the role of T.saltator in bioturbation. The luminophore tracer technique as described by MaHaut & Graf (1987) is applied with a few modifications. Luminophores of the size class 355-450 µm are used in the experiment. The particle tracers are evenly distributed on the sediment surface of each core. In the experiments different numbers of T.saltator are added after the tracers input (control, 1, 3, and 5 individuals per core). During experiments the activity of sand-hoppers in the cores is visually observed; the number of burrow openings at the sediment surface is counted.At the end of the experiment the sediment is removed from the tubes with a piston device and sectioned in horizontal slices. In each slice luminophores are counted and results are analysed. Literature:1. Weslawski, JM; Urban-Malinga, B; Kotwicki, L; Opalinski, K; Szymelfenig, M; Dutkowski, M. Sandy coastlines ? are there conflicts between recreation and natural values?// Oceanological Studies. Gdansk. Vol. 29, no. 2, pp. 5-18. 2000.2. MaHaut M.-L. & G.Graf 1987. A luminophore tracer technique for bioturbation studies. ? Oceanologica Acta 10:323-328.