6.5- Nutrients in Coastal and Marine Waters

This state indicator shows current nutrient concentrations in geographical changes and temporal trends. Discharges of nitrogen and phosphorus from land based sources like urban, industry or agricultural sources cause eutrophication.

Within the context of “Integrated Marine Pollution Monitoring Programme” of Turkey water quality was assessed in all seas of Turkey for the period 2014-2016.

 

GRAPH 46- MEDITERRANEAN SURFACE WATER NO2+NO3-N (NOX) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES (CWB).

 

GRAPH 47- AEGEAN SEA SURFACE WATER NO2+NO3-N (NOX) CONCENTRATION AVERAGES IN COASTAL WATER BODIES (CWB).

Sources: “Integrated Marine Pollution 2014-2016 Programme” Summary Reports (2017).

 

GRAPH 48- BLACK SEA SURFACE WATER NO2+NO3-N (NOX) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES (CWB). red line)

 

GRAPH 49- MARMARA SEA SURFACE WATER NO2+NO3-N (NOX) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES: winter (blue line), summer (red line)

 

Sources: “Integrated Marine Pollution 2014-2016 Programme” Summary Reports (2017).

 

In Mediterranean Sea, high NOX (NO2+NO3-N) concentrations were observed in 2015 winter season due to high precipitations in winter and high riverine discharges. However, for 2016 winter having less precipitation average, NOx values were as low as in summer seasons. Main reason of these annual changes is that nitrate ion-rich rainfall and riverine water entrance were in low levels in 2016 February and surface water NOx was consumed by photosynthesis.

Aegean Sea surface NOX (NO2+NO3-N) concentrations did not show significant differences among seasons. However, in 2016 high concentrations were observed in both summer and winter.

NOx concentrations in Black Sea coasts and at open sea stations showed significant differences among seasons. Winter NOX concentrations were approximately four times of summer values, because of loss by photosynthesis until summer. Especially in winter times, both the high concentrations of NOX and these concentration distributions implies the land based pressures in water bodies. In 2016 Eastern Black Sea showed apparently high concentrations of NOX due to the high levels of precipitation above the average values.

Surface NOX concentrations in Marmara Sea was higher in winter than in summer. However there were also differences among years. Being an inland sea Marmara is exposed to more pressures compared to other seas. Winter season concentration differences could be resulted by precipitation causing increased loads of rivers and meteorological conditions like wind direction and speed.

 

 

 

GRAPH 50- MEDITERRANEAN SEA SURFACE WATER TOTAL PHOSPHORUS (TP) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES: winter (blue line), summer (red line)

 

GRAPH 51- AEGEAN SEA SURFACE WATER TOTAL PHOSPHORUS (TP) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES: winter (blue line), summer (red line)

Sources: “Integrated Marine Pollution 2014-2016 Programme” Summary Reports (2017).

 

GRAPH 52- BLACK SEA SURFACE WATER TOTAL PHOSPHORUS (TP) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES: winter (blue line), summer (red line)

 

GRAPH 53- MARMARA SEA SURFACE WATER TOTAL PHOSPHORUS (TP) AVERAGE CONCENTRATIONS IN COASTAL WATER BODIES: winter (blue line), summer (red line)

Sources: “Integrated Marine Pollution 2014-2016 Programme” Summary Reports (2017).

 

Total phosphorus (TP) concentrations were high especially in inner bays having riverine and household discharges in Mediterranean Sea between 2014-2016. TP summer concentrations were higher than winter concentrations. The lowest concentration was observed in 2016 winter season. In Aegean Sea, winter TP concentrations values were higher than the summer values because of high river load entrance to the sea due to high precipitation. Black Sea TP concentrations in water bodies in 2014-2016 period were between 0.07-5.07 µM/l, and did not show significant changes among seasons. High concentrations of TP along the coast implies the land based pressures. In 2015, TP concentrations were higher than the other monitoring periods.