Eutrophication of the Baltic Sea is a serious problem, and as such it is frequently raised in relevant literature, where potamic supply of nutrients is implicated as one of the causes. Coastal waters like the Puck Lagoon, an area protected within the Natura 2000 network, as well as watercourses in adjacent Coastal Landscape Park, are particularly vulnerable to such degradation. Hence, the aim of our study, which was to determine the volume and fluctuations of transported total nitrogen and phosphorus. Another objective was to try and relate these changes to the transport of nutrients and runoff in streams flowing through Coastal Landscape Park into the Puck Lagoon (the Płutnica, Potok Błądzikowski, Gizdepka, Reda, Zagórska Struga) and into the Baltic Sea (the Piaśnica, Karwianka, Czarna Wda). This research drew on field investigations and laboratory assays performed in the hydrological year of 2009, and had been designed accordingly, including measurements of the flow rate in the selected watercourses and water sampling for further chemical analyses, including determinations of total nitrogen and total phosphorus. In brief, the highest average annual flow rate and load of total nitrogen and total phosphorus were found in the Reda and Piaśnica. The largest load variation, of both nitrogen and phosphorus, occurred in the Zagórska Struga. In most of the watercourses, the load of biogenic substances was strongly correlated with the flow, but the actual power of correlation depended on a stream and biogenes. The strongest statistical relationships for both tested substances (r > 0.8) occurred in the Potok Błądzikowski, Reda, Zagórska Struga and Czarna Wda. The Płutnica was an exception in that there were no statistically significant relationships between the water flow and the load of nutrients. However, the low value of the relationship determined suggests that we should view that series with some caution.

21.2.2016