Patterns and trends in nutrients and phytoplankton in Dutch coastal waters: comparison of time-series analysis, ecological model simulation, and mesocosm experiments

In the Dutch coastal zone, nutrient and chlorophyll concentrations show gradients of up to one order of magnitude perpendicular to the coast within the first 30–50 km offshore. Time-series analysis reveals significant decreasing trends for dissolved inorganic phosphorus (40%) and total phosphorus (35%) and an increase in the dissolved inorganic N:P ratio from 25–30 to 40–55 over the period 1988–1995. Trends in nitrogen (−15%), silicate (stable), and chlorophyll are smaller and generally not statistically significant. The trends in phosphorus reflect a proportional and immediate response to dec... Mehr ...