Spatial distribution of biological and physical sediment parameters in the western Gulf of Gdańsk*

The ongoing processes of surface sediments and their biological activity are highly dynamic. Sediment samples for the current study were collected at 48 stations in the Gulf of Gdańsk in May 2006, and the following sediment parameters were analysed: grain size distribution, water volume, permeability, organic matter content, chlorophyll a and EPS carbohydrate concentrations. The spatial distributions of the different parameters varied distinctly, which suggested a strongly diversified bottom environment. The results obtained were used to create spatial distribution maps, and statistical analyses of the results showed that the Gulf’s bottom can be divided into four areas impacted by different parameters: (1) the inner Puck Bay; (2) the outer Puck Bay; (3) the outer Gulf of Gdańsk; (4) the open sea. Distinct correlations between microbenthic activity, expressed as carbohydrate and chlorophyll concentrations, and sediment physical parameters were noted. The bottom of the Gulf of Gdańsk appeared to be strongly influenced by wave motion. This led to the conclusion that the most dynamic areas are the shallow coastal zones, which play important roles in water purification processes and in the proper functioning of the Gulf of Gdańsk ecosystem. This study of the spatial distribution of sediment parameters is the first of its kind, and the widest-ranging study of sediments ever to be conducted in this region.