Since the Quality Status Report 2010 there have only been small changes in chlorophyll concentrations in the Greater North Sea (Region II), Celtic Seas (Region III) and Bay of Biscay and Iberian Coast (Region IV). Eleven assessment areas, all in OSPAR Region II show concentrations exceeding the threshold in the fourth application of the Common Procedure (COMP4) assessment period 2015 to 2020. This applies to 46% of the surface area of river plumes and 22% of the surface area of coastal areas (total surface area in Regions II, III, IV).

Since the Quality Status Report 2010, winter concentrations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) have continued to decrease, mainly in coastal and some shelf areas in the Greater North Sea (Region II), Celtic Seas (Region III) and Bay of Biscay and Iberian Coast (Region IV). In the assessment period for the fourth application of the common procedure (COMP4) 2015-2020, 61% of the river plumes, 24% of coastal waters and less than 1% of shelf waters in the OSPAR area assessed (surface area km²) were not in good status for DIN. For DIP 38% of the river plumes and 11% of coastal waters were not in good status.

In most areas assessed, concentrations of dissolved oxygen near the seafloor are above the threshold value of 6mg/l. However, oxygen depletion has been observed in the Eastern North Sea, Kattegat coastal and Kattegat Deep, though improvements in levels of dissolved oxygen concentrations have been observed in the Kattegat areas.

These assessments were produced under OSPAR's Hazardous Substances and Eutrophication Committee currently Chaired by Philip Axe (Sweden). Please visit our website for more information.