D5

5.1 Nutrients level

5.1.1 Nutrient concentration

5.2 Direct effects of nutrient enrichment

5.2.1 Chlorophyll concentration

5.2.2 Water transparency

5.2.3 Abundance of macroalgae

5.2.4 Shift in floristic species composition

5.3 Indirect effects of nutrient enrichment

5.3.1 Abundance of seaweeds and seagrasses

5.3.2 Dissolved oxygen

MAL-EL-MS-AL: For descriptors 3, 5, 6, 8 and 9 it is attempted to approach GES quantitatively using environmental thresholds/limits to describe the desired state of GES. For descriptors 1, 2, 4,7 and 10 a qualitative description of what GES will be like is provided.

MAL-EL-MS-AL: For descriptors 3, 5, 6, 8 and 9 it is attempted to approach GES quantitatively using environmental thresholds/limits to describe the desired state of GES. For descriptors 1, 2, 4,7 and 10 a qualitative description of what GES will be like is provided.

MAL-EL-MS-AL: For descriptors 3, 5, 6, 8 and 9 it is attempted to approach GES quantitatively using environmental thresholds/limits to describe the desired state of GES. For descriptors 1, 2, 4,7 and 10 a qualitative description of what GES will be like is provided.

MAL-EL-MS-AL: For descriptors 3, 5, 6, 8 and 9 it is attempted to approach GES quantitatively using environmental thresholds/limits to describe the desired state of GES. For descriptors 1, 2, 4,7 and 10 a qualitative description of what GES will be like is provided.

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion
• It constitutes the assessment area South Aegean Sea belonging in the subregion Mediterranean sea:Aegean-Levantine sea

• InputN_Psubst
• InputOrganics
• LitRock
• LitSed
• MarineCoast
• NutrientLevels
• NutrientOrgEnrich
• OxygenLevels
• RedSalinity
• ShallCoarseSed
• ShallMxdSed
• ShallRock
• ShallSand
• Transparency
• Turbidity (silt/sediment loads)
• VarSalinity

• InputN_Psubst
• InputOrganics
• LitRock
• LitSed
• MarineCoast
• NutrientLevels
• NutrientOrgEnrich
• OxygenLevels
• RedSalinity
• ShallCoarseSed
• ShallMxdSed
• ShallRock
• ShallSand
• Transparency
• Turbidity (silt/sediment loads)
• VarSalinity

• InputN_Psubst
• InputOrganics
• LitRock
• LitSed
• MarineCoast
• NutrientLevels
• NutrientOrgEnrich
• OxygenLevels
• RedSalinity
• ShallCoarseSed
• ShallMxdSed
• ShallRock
• ShallSand
• Transparency
• Turbidity (silt/sediment loads)
• VarSalinity

• InputN_Psubst
• InputOrganics
• LitRock
• LitSed
• MarineCoast
• NutrientLevels
• NutrientOrgEnrich
• OxygenLevels
• RedSalinity
• ShallCoarseSed
• ShallMxdSed
• ShallRock
• ShallSand
• Transparency
• Turbidity (silt/sediment loads)
• VarSalinity

D5

5.1

5.1.1

5.2

5.2.1

5.2.2

5.2.3

5.2.4

5.3

5.3.1

5.3.2

In order to achieve GES in the marine environment, it is necessary to keep nutrients -compounds of nitrogen and phosphorus – in the water column at levels which do not accelerate primary production. If there is no excess organic matter and increased suspended algae, water transparency will be satisfactory allowing photosynthesis process to evolve naturally and allow perennial seaweeds and sea grasses to grow. In addition, chlorophyll concentration in the water column will not be increased and oxygen levels will establish a satisfactorily oxygenated environment without anoxic or hypoxic conditions. When an ecosystem is in GES the nutrients are preserved at moderate levels and any human-induced eutrophication phenomena are prevented. Hence, the floristic composition of the marine environment is not altered disturbing the diatom to flagellate ratio, or causing toxic algal blooms. As a result, the ecosystems retain their balance and biodiversity is preserved. Therefore, the overall quality of the marine environment is maintained.In the subregion examined it is deemed that only a maximum proportion of 5% of the assessment area is not in Good Environmental Condition, and as a result occasionally presents eutrophication phenomena due to anthropogenic intervention. There are particular hot spots in coastal areas, mainly enclosed gulfs, where nutrients concentrations exceed threshold values as a result of land –based or sea based human activities; Amvrakikos Gulf and Patraikos Gulf.

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion = To achieve GES, nutrients should be kept at moderate levels. Therefore, the suggested threshold values (limit reference points) are based on Karydis (1999) and Wasmund et al (2001) eutroficaton criteria.

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion = NO3 <1μM PO4 <0,5μM

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion = Chl-a<1.5μg/l, water transparency should be at least 5 m

• Hellenic Republic's marine waters part of the Aegean-Levantine subregion = DO>80%, There should be no occurrence of toxic algal blooms, or increase of toxic floristic species

5%

5%

LimitReferencePoint

LimitReferencePoint

TargetReferencePoint

The baseline used to establish the threshold values is that of the pristine state of open sea surface waters.NO3 = 0.6 μM PO4 =0,2 μM

The baseline used to establish the threshold values is that of the pristine state of open sea surface waters. Chl-a=0.4 μg/l, Water transparency should be at 10 m

The baseline used to establish the threshold values is that of the pristine state of open sea surface waters. DO=95% .

The asessment method involves the monitoring of the paramaters mentioned and the comparison of the measured values to the thresholds set.

The asessment method involves the monitoring of the paramaters mentioned and the comparison of the measured values to the thresholds set.

The asessment method involves the monitoring of the paramaters mentioned and the comparison of the measured values to the thresholds set.