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International Journal of Marine Science 2014, Vol.4, No.17: 160-165
http://ijms.sophiapublisher.com
162
Table 1 The phytoplankton growth rate (µ), the concentration of chlorophyll-
a
(Chl
a
), specific
Primnesiophyta biovolume
(Bprim.),
Bacillariophyta biovolume
(Bbacil.) and
Dinophyta biovolume
(Bdinoph.) algae, nutrients in the studied waters of the Black Sea in
May 2013
Table 2 The microzooplankton grazing of phytoplankton (g), the net phytoplankton growth rate (µ – g) and ratio g/µ in the studied
waters of the Black Sea in May 2013
No. station
E. huxleyi
,
cell/l*10
6
g,
d
-1
µ – g,
d
-1
g/µ,
%
n
Western part of the sea, near-shore waters
26, 28, 35, 38, 39;
33
34
1.8–4.2
0.28
0.15
0,04–0,50
0.53
0.13
0.04–1.00
-0.27
0.84
4-96
200
13
5
1
1
Western part of the sea, open-sea waters
18(1), 21, 18(2), 22,
18(3)
1.3–2.7
0.19–0.99
0.44–0.84
18–72
5
Eastern part of the sea, near-shore waters
7, 9, 13, 14, 16
1.6–4.3
0.15–0.24
0.56–1.18
12–30
5
Nearly all of the seawater areas were blooming. The
numbers of
E. huxleyi
in the sea surface varied from
1.3 to 4.3·10
6
cell/l amounting on the average to 94 %
of the total phytoplankton abundance. The specific bio-
volume generated by this coccolithophore which domin-
ated among Primnesiophyta ranged between 60-90%
of the total phytoplankton biovolume (Table 1).
Chlorophyll-
а
concentration in the blooming sea water
was not large (0.10 – 0.18 mg/m
3
) and specific growth
rate of the phytoplankton varied inconsiderably (0.80
– 1.44 d
-1
). In the seawater areas receiving the Dnieper
input (st. 33 and 34) diatoms, primarily
Cerataulina
pelagica
,
Cyclotella caspia
and large
Pseudosolenia
calcar-avis
, were the major contributor to the total
phytoplankton abundance and biovolume. The
chlorophyll-
а
content measured in samples collected
in the brackish-water locations (st. 33 and 34) was
several times as large as in other areas – 1.10 and 0.33
mg/m
3
, correspondingly. Specific growth rate of the
total phytoplankton was relatively high (0.97 d
-1
) at st.
34 where seawater salinity was estimated 16.30 ‰, and
about 3-fold lesser at station 33 where the salinity
decreased to 15.50 ‰.
The specific rate of phytoplankton consumption by
microzooplankton measured in the sea surface usually
ranged from 0.04 to 0.99 d
-1
(Table 2). The predatory
activity was similarly low (0.15 – 0.24 d
-1
) in the
eastern Black Sea off the Crimean shore and increased
to the largest (0.19 – 0.99 d
-1
) in the deep-water part of
the sea. In the shallow-water areas occurring from the
NW Black Sea to the western coast of the Crimea
estimates of the microzooplankton predatory pressure
No. station
µ,
d
-1
Chl
а
,
mg/m
3
В
Prim.
,
%
В
Bacil.
,
%
В
Dinoph.
,
%
N-NO
3
,
mmol/m
3
N-NH
4
,
mmol/m
3
P-PO
4
,
mmol/m
3
Western part of the sea, near-shore waters (n =7)
26, 28, 35,
38, 39;
33
34
0.80–1.35
0.26
0.97
0.10–0.12
1.10
0.33
70.5–87.6
4.5
8.0
0–13.5
92.5
87.7
2.7–20.1
3.0
4.2
0.14–0.28
0.23
0.17
0.83–1.80
1.55
1.88
0.28–0.32
0.35
0.29
Western part of the sea, open-sea waters (n =5)
18(1),
21,
18(2),
22,
18(3)
0.94–1.44
0.10–0.13
60.0–84.7
0–10
14.2–30
0.10-0.29
0.54–1.33
0.27–0.37
Eastern part of the sea, near-shore waters (n = 5)
7, 9, 13, 14,
16
0.97–1.34
0.10–0.18
60–89.6
0–23.2
8.9–15.2
0.05–0.27
0.72–1.80
0.20–0.30