STS085-502-104 (7 - 19 August 1997) --- The abundant plankton, microscopic organisms, are taking the shape of the currents in the Baltic Sea offshore from Gdansk, Poland. Plankton blooms occur when there is enough nutrient in the water to support rapid growth and reproduction of the microorganisms. Gdansk is situated at the mouth of the Vistula River on the north coast of Poland. It is a major industrial center for shipyards, metallurgical and chemical plants, timber mills, food-processing facilities and more recently (since 1975) for coal exports and petroleum imports.