The objectives of this study were to indicate the relationship between chlorophyll levels, dissolved metal group minerals and phosphates in the studied area of the Central Polish Coastal Waters and to relate these data to the influence of the terrestrial environment. In 2020, in the Central Polish Coastal Waters (PLB990002), which is a special area for the protection of birds, tests were carried out on the concentrations of chlorophyll, phosphates, dissolved microelements: zinc, cobalt, nickel and iron, and electrolytic conductivity. For the analysis of dissolved microelements, a graphite cuvette version of atomic absorption spectrophotometer (AAS-GF) was used. Chlorophyll and phosphates were studied using UV-VIS spectrophotometer. The concentrations obtained in coastal sea water in the spring after the wintering of waterfowl and in the autumn were compared. Microelement and phosphate concentrations were higher in spring than in autumn. The relationship between the level of chlorophyll and phosphates and the tested microelements in coastal waters was demonstrated, and the results were linked to the possible sources of these chemical substances, such as wintering of birds, tourism, municipal and port management. It was also observed that the upwelling effects occurred in the study area, which significantly influenced changes in the chemical composition of sea water.