Bacteriological quality of the sand beach in Sopot (Gdansk Bay, southern Baltic)

This paper presents the results of two year's of research of the coastal se awater and sandy sediments along the beach in Sopot. The investigations wer e performed from May 1997 to April 1999. Four testing sites, perpendicular to the shore, were chosen in the area located between the mouths of two str eams, Grodowy Potok and Kamienny Potok. It was revealed that the total numb er of mesophilic bacteria increased as distance from the waterline increase d. In contrast, the number of E.coli was highest in the coastal water and i n sand points close to the water. This indicates that there are two sources of microbiological pollution at work on sandy beaches. The first source is seawater which contains E. coli bacteria and the second is polluted air fr om the land that conveys the mesophilic bacteria, The high levels of E. col i bacterial pollution in the sand in the spring-summer season indicate that it is essential to monitor the sanitary conditions of this area during thi s period.