Study of the Dynamics of Phosphorus
263
Ae r---------~--------~~~----~
1.5
1.2
0.9
0.6
0.3
Fig.S.1S. Examples of calculation P04-P regeneretion rates in water column (Ae) after
measured rates of its uptake by the microplankton (At) and changes of its absolute
content in water (±L\ P) in bottle experiments; the measurements were accomplished
in the Okhotsk Sea in summer; all numbers are given as ~g P 1-1 day-l
above, we have the possibility to calculate also the regeneration rate (Sorokin
1996; Fig. 5.18).
Radioactive phosphorus 32p was initially applied for the study of nutrition
in aquatic animals (see Sect. 3.1). The first attempts to use labeled phosphate
32P04 to estimate P04P in situ consumption rates were made already in the
1960s (Pomeroy 1961; Johannes 1964; Rigler 1966). At present, significant
experience has been acquired in its application for characterization of phosphorus metabolism in aquatic ecosystems (Fedorov and Sorokin 1977;
Harrison et al. 1977; Taylor and Lean 1981; Krempin et al. 1981; Berman 1985;
Sorokin 1985, 1990a).
5.7.2 Measuring P04P Uptake-Rates by Microplankton
5.7.2.1 Preparation of the Isotope Working Solution
The radioisotopes 32p or 33p are used for labeling inorganic phosphate. The
latter, while being more expensive than 32p, is much more convenient for field
work. It has about twice as long a half-life and significantly softer ~-radiation
(see Table 1.1). When working with these radioisotopes, some precautions
must be taken in the preparation of the working solution from the batch. This
operation should be carried out behind a clear Plexiglas sheet about 1 cm
thick. Operations with ready-for-use working solutions, which have rather low
radioactivity (2-3 /-lei ml- 1 ), can be done without such precautions, with only
goggles to protect the eyes.
263
Ae r---------~--------~~~----~
1.5
1.2
0.9
0.6
0.3
Fig.S.1S. Examples of calculation P04-P regeneretion rates in water column (Ae) after
measured rates of its uptake by the microplankton (At) and changes of its absolute
content in water (±L\ P) in bottle experiments; the measurements were accomplished
in the Okhotsk Sea in summer; all numbers are given as ~g P 1-1 day-l
above, we have the possibility to calculate also the regeneration rate (Sorokin
1996; Fig. 5.18).
Radioactive phosphorus 32p was initially applied for the study of nutrition
in aquatic animals (see Sect. 3.1). The first attempts to use labeled phosphate
32P04 to estimate P04P in situ consumption rates were made already in the
1960s (Pomeroy 1961; Johannes 1964; Rigler 1966). At present, significant
experience has been acquired in its application for characterization of phosphorus metabolism in aquatic ecosystems (Fedorov and Sorokin 1977;
Harrison et al. 1977; Taylor and Lean 1981; Krempin et al. 1981; Berman 1985;
Sorokin 1985, 1990a).
5.7.2 Measuring P04P Uptake-Rates by Microplankton
5.7.2.1 Preparation of the Isotope Working Solution
The radioisotopes 32p or 33p are used for labeling inorganic phosphate. The
latter, while being more expensive than 32p, is much more convenient for field
work. It has about twice as long a half-life and significantly softer ~-radiation
(see Table 1.1). When working with these radioisotopes, some precautions
must be taken in the preparation of the working solution from the batch. This
operation should be carried out behind a clear Plexiglas sheet about 1 cm
thick. Operations with ready-for-use working solutions, which have rather low
radioactivity (2-3 /-lei ml- 1 ), can be done without such precautions, with only
goggles to protect the eyes.