Trends in dissolved inorganic nitrogen and orthophosphate concentrations in Europe’s transitional, coastal and marine waters, 1980-2021

Units

The trends have no units

Additional information

- DIN refers to the sum of ammonium, nitrite and nitrate concentrations, although in many samples not all three forms of nitrogen were measured.

- Data were aggregated into squares with sides of squares with sides of 1,375km for coastal stations within 20km from the coastline (m=80) and 5.5km for open water station more than 20km away from the coastline (m=20). A masking of 5km inwards from the coast was also applied.

- Temporal trends were estimated with the non-parametric Mann-Kendall test. Only stations having data of at least 5 years and having at least data in the last 5-year period (2017-2021) were considered. A p-value < 0.05 was used to consider a statistically significant trend.

- SLPG was considered for the winter months: January-March for stations within Baltic Sea and east of 15 E longitude. Period from January–February was used for all other stations.