To estimate the annual variability of the sedimentation flux of photosynthesis
zone deep water area of the Black Sea used two variants of calculation. The first is
based on the use of long-term data measured total primary production. The basis of
the model analysis of the monthly mean values of the “new” primary production
were laid as its value corresponds to the amount of organic matter exported from the
zone of photosynthesis in the deep layers of the sea (Eppley and Peterson 1979).
Average values of the “new” primary production is determined by the difference
between the measured average monthly amount of the total primary production
(TPP) in the period (1973–1995) (Vedernikov and Demidov 1997) and the values of
regenerative products, calculated in accordance with the integral value of the
regeneration of phosphorus flux over the same time period (Parkhomenko 2005),
taking into account the uptake of phosphate by bacteria (Parkhomenko 2009).
Sedimentation flux of P POM was integral monthly average of the “new” primary
production and the weight ratio C: P ¼ 106: 1 (Table 19.1). According to the data in
Table 19.1 P POM flux values during the year varied over a wide range
(0.019–0.336 mg-atP∙m
À2
∙day
À1 ). The highest values of this indicator varied in
the range (0.065–0.336 mg-atP∙m
À2
∙day
À1 ) and consistent with the cold season
(November–March). In the warm season (April–October), they decreased and
ranged from 0.021 to 0.147 mg-atP∙m
À2
∙day
À1 , and the average value of the flux
was equal to 44.89 mg-atP∙m
À2
∙year
À1 .
The second variant of the sedimentation flux P POM annual variability assessment
is based on the measured and calculated average concentrations of photosynthesis
zone (Parkhomenko and Kukushkin 2015). Sedimentation P POM flux was calculated
as the product of the average concentration in the P POM in photosynthesis zone and
deposition rate (Table 19.2). The deposition rate P POM calculated by dividing the
monthly average flux sedimentation, resulting in model calculations (Table 19.2)
and its weighted average concentrations in the photic layer of pelagial the Black
Sea. As shown in Table 19.2 the value of this indicator during the year varied over a
wide range (0.021–0.341 mg-atP∙m
À2
∙day
À1 ). The highest values of this flux
(0.065–0.341 mg-atP∙m
À2
∙day
À1 ) correspond to the cold season (November–
March), they decreased and varied from 0.021 to 0.147 mg-atP∙m
À2
∙day
À1 in the
warm season (April–October), and the average value of the flux was 46 mg-atP∙m
À2
∙year
À1 .
Annual variability of sedimentation P POM flux generally was in line with the
seasonal changes to the annual weighted average concentration of P POM of chlorophyll “a” and phytoplankton biomass in the photosynthetic zone, indicating a key
role not only seasonal variability of phytoplankton and of hydro-physical and
sedimentary processes on the intensity of the sedimentation flux of P POM . Similar
results were obtained in C POM and N POM in the photosynthesis zone sedimentation
flux studies central western cyclonic gyre in the Black Sea (Gulin et al. 1995). The
seasonal changes of the sedimentation flux P POM , calculated on the average
monthly values of the “new” primary production are well matched with the annual
variability of the sedimentation flux P POM , calculated on a weighted average of its
concentration in the photic layer. Average annual values were almost identical and
were, respectively, 44.9 and 46 mg-atP∙m
À2
∙year
À1 , which indicates a high
19 Phosphorus Fluxes in the Pelagic Zone of the Black Sea
347
zone deep water area of the Black Sea used two variants of calculation. The first is
based on the use of long-term data measured total primary production. The basis of
the model analysis of the monthly mean values of the “new” primary production
were laid as its value corresponds to the amount of organic matter exported from the
zone of photosynthesis in the deep layers of the sea (Eppley and Peterson 1979).
Average values of the “new” primary production is determined by the difference
between the measured average monthly amount of the total primary production
(TPP) in the period (1973–1995) (Vedernikov and Demidov 1997) and the values of
regenerative products, calculated in accordance with the integral value of the
regeneration of phosphorus flux over the same time period (Parkhomenko 2005),
taking into account the uptake of phosphate by bacteria (Parkhomenko 2009).
Sedimentation flux of P POM was integral monthly average of the “new” primary
production and the weight ratio C: P ¼ 106: 1 (Table 19.1). According to the data in
Table 19.1 P POM flux values during the year varied over a wide range
(0.019–0.336 mg-atP∙m
À2
∙day
À1 ). The highest values of this indicator varied in
the range (0.065–0.336 mg-atP∙m
À2
∙day
À1 ) and consistent with the cold season
(November–March). In the warm season (April–October), they decreased and
ranged from 0.021 to 0.147 mg-atP∙m
À2
∙day
À1 , and the average value of the flux
was equal to 44.89 mg-atP∙m
À2
∙year
À1 .
The second variant of the sedimentation flux P POM annual variability assessment
is based on the measured and calculated average concentrations of photosynthesis
zone (Parkhomenko and Kukushkin 2015). Sedimentation P POM flux was calculated
as the product of the average concentration in the P POM in photosynthesis zone and
deposition rate (Table 19.2). The deposition rate P POM calculated by dividing the
monthly average flux sedimentation, resulting in model calculations (Table 19.2)
and its weighted average concentrations in the photic layer of pelagial the Black
Sea. As shown in Table 19.2 the value of this indicator during the year varied over a
wide range (0.021–0.341 mg-atP∙m
À2
∙day
À1 ). The highest values of this flux
(0.065–0.341 mg-atP∙m
À2
∙day
À1 ) correspond to the cold season (November–
March), they decreased and varied from 0.021 to 0.147 mg-atP∙m
À2
∙day
À1 in the
warm season (April–October), and the average value of the flux was 46 mg-atP∙m
À2
∙year
À1 .
Annual variability of sedimentation P POM flux generally was in line with the
seasonal changes to the annual weighted average concentration of P POM of chlorophyll “a” and phytoplankton biomass in the photosynthetic zone, indicating a key
role not only seasonal variability of phytoplankton and of hydro-physical and
sedimentary processes on the intensity of the sedimentation flux of P POM . Similar
results were obtained in C POM and N POM in the photosynthesis zone sedimentation
flux studies central western cyclonic gyre in the Black Sea (Gulin et al. 1995). The
seasonal changes of the sedimentation flux P POM , calculated on the average
monthly values of the “new” primary production are well matched with the annual
variability of the sedimentation flux P POM , calculated on a weighted average of its
concentration in the photic layer. Average annual values were almost identical and
were, respectively, 44.9 and 46 mg-atP∙m
À2
∙year
À1 , which indicates a high
19 Phosphorus Fluxes in the Pelagic Zone of the Black Sea
347