The vast majority of Marine Reporting Units were found to represent subGES with regard to benthic communities. This was due to subGES values of the B zoobenthos index as well as subGES values of SM1 and ESMIz macrophyte indexes. The B zoobenthos index has been shown to be strongly dependent on total nitrogen concentrations near the bottom. These concentrations are in turn a manifestation of eutrophication. Macrophyte communities are also known to be dependent on nutrient concentration levels, although the relationships in this case are more complex. Nevertheless, it is clear that lasting improvement of the quality of benthic communities will not be possible without major reductions of nutrient inputs. As explained in the case of Exception XX (Non-achievement of GES with regard to descriptor D5 ""Eutrophication""), the required reductions of nutrient levels in Polish Marine Waters will be impossible without significant efforts on the part of other countries of the Baltic Sea Basin, i.e. Denmark, Estonia, Finland, Germany, Lithuaniam, Latvia, Russia and Sweden, but also Belarus, the Czech Republic and Ukraine.

The vast majority of Marine Reporting Units were found to represent subGES with regard to benthic communities. This was due to subGES values of the B zoobenthos index as well as subGES values of SM1 and ESMIz macrophyte indexes. The B zoobenthos index has been shown to be strongly dependent on total nitrogen concentrations near the bottom. These concentrations are in turn a manifestation of eutrophication. Macrophyte communities are also known to be dependent on nutrient input levels, although the relationships in this case are more complex. Nevertheless, it is clear that lasting improvement of the quality of benthic communities will not be possible without major reductions of nutrient inputs. As explained in the case of Exception XX (Non-achievement of GES with regard to descriptor D5 ""Eutrophication""), the reqiured reductions of nutrient levels are very unlikely before 2050.

No EU or regional GES indices have been adopted with regard to physical loss of seabed (D6C1). However, three transitional water bodies of Polish Marine Waters have been found to represent subGES status basing on a national indicator. The reason for the subGES status is existing infrastructure related to, among others, inland navigation, tourism and recreation, fisheries and other interests. Restoration of GES in these water bodies would require the dismantling of some of this infrastructure and would therefore be detrimental to legitimate economic interests of local and regional importance. In some cases, as in the case of the Vistula river mouth, which is actually a man-made outlet built over a century ago, the dismantling of existing hydroengineering structures and restoring the river's original course would not only have serious economic consequences, including greatly increased risk of flooding in Gdansk, but would actually destroy important habitats which currently host a number of threatened bird species and Poland's only grey seal haul-out site. For these reasons, Poland believes restoring GES with regard to criterion D6C1 in the three water bodies concerned would be against public interest.