Biologia, Bratislava, 61/Suppl. 18: S203—S212, 2006
Section Zoology
DOI: 10.2478/s11756-006-0132-7
Seasonal dynamics of chironomids in the profundal zone
of a mountain lake (Ľadové pleso, the Tatra Mountains, Slovakia)
Jolana Tátosová1 & Evžen Stuchlík2
1
Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benátská 2, CZ-12801 Prague 2,
Czech Republic; e-mail: [email protected]
2
Hydrobiological Station, Institute for Environmental Studies, Charles University in Prague, P.O. Box 47, CZ-38801 Blatná,
Czech Republic; e-mail: [email protected]
Abstract: The profundal community of Ľadové pleso (an oligotrophic high mountain seepage lake at an altitude of 2,057
m with a max. depth of 18 m and an ice-cover period from October – July) was studied from December 2000 – October
2001. Chironomidae, the most significant part of the studied community, are represented by four taxa and dominated by
Micropsectra radialis Goetghebuer, 1939 and Pseudodiamesa nivosa (Goethgebuer, 1928). These two species showed a 1-year
life cycle. The total densities of chironomids varied from 0 to 5,927 ind. m−2 ; no chironomids, or very low densities, were
found during the winter/spring period, probably due to low oxygen concentrations in the medial part of the lake. These low
oxygen concentrations probably caused the relocation of larvae from the medial part of the sedimentary area at the same
time.
Key words: Non-biting midges, Chironomidae, life history, distribution, migration, environmental parameters, Slovakia.
Introduction
High mountain glacial lakes represent a very special environment for water organisms because of their low average annual temperature, oligotrophic character and
the minor impact of human activities. These special
properties aroused interest in lakes in the High Tatra
Mountains (Mts), although the accessibility of lakes was
difficult, which especially complicated the investigation
of the profundal sediments. The first investigation of
profudnal fauna was carried out in the 1930s by Hrabě
and Zavřel. In contrast to lowland lakes or ponds, the
fauna of the deepest part of high mountain lakes was
very poor and was usually formed only by oligochaetes
and the larvae of chironomids (Hrabě, 1939, 1942; Zavřel, 1937). Later, the study of chironomids was connected with research of trophic status changes in some
Tatra lakes (Ertlová, 1964), and since the 1980s the
chironomid fauna has been studied mainly with an emphasis on the process of acidification (Ertlová, 1987;
Tátosová, 2002; Bitušík et al., 2006). The sampling
of chironomid larvae is often an important part of systematic limnological research because of their very sensitive reaction to the amount and quality of available
food, as well as temperature, concentration of dissolved
oxygen, and pH (Sæther, 1979; Raddum & Sæther,
1981). Not only their abundances or taxonomic composition, but also their life history, can reflect inclement
c
2006
Institute of Zoology, Slovak Academy of Sciences
conditions of the mountain climate (Armitage et al.,
1995). Ľadové pleso was chosen as the key lake in the
Tatra Mts for the Fifth Framework Program of European Union: project EMERGE, which made possible
systematic investigations of biota life cycles and seasonal variations in lake water chemistry.
This paper summarizes results of the first complete
round-year study of chironomids in the profundal zone
of an oligotrophic high mountain Tatra lake. The main
aim of the presented study is to describe the population
dynamics of chironomids in Ľadové pleso in relation to
environmental factors and phytoplankton production.
Study site
Ľadové pleso (49◦ 18 41 N, 20◦ 16 29 E) is located in the
Veľká Studená dolina valley on the southern slope of the
High Tatra Mts at 2,057 m a.s.l. The lake area is 1.72 ha,
catchment area 12.3 ha, and maximum depth 18 m. Granite
dominates in the catchment, and bare rocks cover 85% of
its area (KOPÁČEK et al., 2006). The lake has no visible
inflow or outflow, and the lake water level oscillates in-depth
by more than 5 m during the year because of its seepage
character (TUREK, 2002; KŘEČEK et al., 2006). Majority of
the lake bottom consists of rocks, and fine-grained sediment
is localized in the deepest part of the lake (Fig. 1). There
are no fish in the lake.
Ľadové pleso is situated at high elevation, which influences the duration of ice-cover and average annual temperaUnauthenticated
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J. Tátosová & E. Stuchlík
Fig. 1. Bathymetry of Ľadové pleso. The stars indicate the coring sites and the arrows show the shift of the sample sites during the
investigated period. The circles ⊗ indicate the positions of the emergence traps. The triangle marks the place of the sedimentary
traps location.
ture. Despite its location and generally oligotrophic character, this lake is one of the most productive lakes in the High
Tatra Mts, probably due to its seepage character (FOTT
et al., 1987). This lake remained non-acidified during the
peak of acidification in this area (STUCHLÍK et al., 1985;
FOTT et al., 1994; KOPÁČEK et al., 2000); nevertheless,
a temporary and partial acidification of the upper part of
the water column (to a depth of ∼5 m) has been repeatedly
recorded at the end of the snow/ ice melting period, when
pH dropped below 6 in this part of the lake water volume
(DARGOCKÁ et al., 1997; KNESLOVÁ et al., 1997; TUREK,
2002).
Methods
Three sampling stations were chosen in the profundal zone
at depths varying from 15 to 18 m. Sites A and C were
situated at the edges of the sedimentary area, site B in the
middle of this area (Fig. 1). This location of sample sites was
chosen so that the spatial distribution of the chironomid larvae would be recorded. The sample sites were moved slightly
in a clockwise direction at each sampling in order not to
take samples from the same places and to obtain samples
from the whole sedimentary area. Sediment was obtained
by a Kajak corer with a sampling area of 28 cm2 . Four core
samples were taken at each site, seven times in the period
from December 2000 to October 2001. In total, 84 samples
were taken and processed; each sample was sieved through
a 100 µm polypropylene mesh in the shape of a plankton
net (DAVIS, 1984) and stored in 4% formalin. Animals were
sorted by hand in the laboratory, and head capsules were
photographed and measured using LUCIA software (Olympus C&S). They were then divided into four instar groups
based on size groups formed from the capsule width and
length measurements (Tab. 1).
Six emergence traps were installed above different lake
depths (Fig. 1). Traps with fixing solution could not be used
in Ľadové pleso because of concurrent analyses of organic
pollutants in the lake water. The “live” emergence traps
used instead require daily control that was not possible at
this site, therefore the time of the trap exposition varied
and the results are not suitable for the inference of chironomid biomass production. These installed traps were used
with the aim to obtain chironomid imagoes for more reliable identification.
Vertical stratification of physical and chemical parameters (temperature, pH and dissolved oxygen) was measured
in situ by a Hydrolab H2O multi-parameter probe and data
logger Surveyor 3, (Hydrolab, USA) in 2 week intervals. Vertical samples for analyses of chlorophyll-a and total volume
of seston were taken 9 times from September 2000 to October 2001, and during the winter period surface and bottom
samples were also taken on the following dates: 15 March,
6 April, 11 May and 20 June. The water samples for determination of chlorophyll-a were filtered through Whatman GF/C glass fiber filters, and after hot extraction in
a 5 : 1 mixture of acetone : methanol (PECHAR, 1987)
analyzed fluorometrically on a Turner TD-700 (Turner,
USA). For more details of the procedure see FOTT et al.
(1999). Samples were analyzed for total volume of seston
(TVP3.3-16800 , mm3 L−1 ) by filtration through a 40 µm
mesh and determination with a Coulter Counter model ZB
with a tube of 70 µm aperture size (DARGOCKÁ et al., 1997).
The amount of particulate matter accumulated at the
lake bottom was taken using a sediment trap, which was
suspended at a depth of 13 m (Fig. 1). The trap was formed
by four 50 cm long tubes with a diameter of 6 cm. Durations
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Table 1. Measured parameters of larval head capsules of M. radialis and P. nivosa.
Width (µm)
M. radialis
Instar: 1
2
3
4
P. nivosa
Instar: 1
2
3
4
Length (µm)
n
Mean
Min
Max
SE
n
Mean
Min
Max
SE
5
50
84
122
79.26
131.75
208.27
318.51
64.28
104.65
163.15
251.64
96.06
154.48
240.94
376.91
11.83
9.80
15.17
21.20
6
49
87
124
83.36
134.43
214.10
327.51
74.74
108.32
174.48
260.85
93.25
150.73
242.03
388.94
7.50
11.71
13.56
24.20
1
6
8
14
181.66
282.40
492.33
765.56
181.66
261.48
429.24
668.86
181.66
301.08
551.15
859.74
16.67
44.32
48.63
1
6
9
14
182.68
306.19
526.36
903.04
182.68
293.73
451.03
760.38
182.68
329.58
589.73
1100.42
12.86
45.39
82.78
Key: n – number of measurements; Max – maximum, Min – minimum, SE – standard error.
Table 2. Time intervals of the sedimentary traps exposure.
Start of
an exposure
End of
an exposure
Trap
depth
Duration of
an exposure (days)
8.12.2000
15.2.2001
24.5.2001
3.7.2001
3.8.2001
31.8.2001
30.9.2001
14.2.2001
23.5.2001
30.6.2001
2.8.2001
29.8.2001
27.9.2001
26.10.2001
13
13
13
13
13
13
13
68
97
37
30
26
27
26
0
-3
-6
of exposure are summarized in Table 2. TPV was analyzed
from this material by the method described above.
-9
-12
-15
-18
O
N
D
J
F
M
A
M
J
J
A
S
O
O
N
D
J
F
M
A
M
J
J
A
S
O
0
-3
Results
-6
-9
Physical parameters and food supply of Ľadové pleso
Ľadové pleso is a dimictic lake with a long period of
winter ice cover and a short period of summer stratification (Fig. 2). The study period began during the
autumn circulation (about 24.10.2000), that lasted 14
days. Winter stratification followed with a duration of
245 days; a stable ice cover was created in early December and lasted 214 days, with a maximal thickness of
270 cm in the spring. Ice melting started in the littoral
part of the lake in the middle of May, and the final disappearance of ice from the lake surface took place at the
beginning of July. The following spring circulation proceeded for 13 days and then the summer stratification
developed at the beginning of August (47 days duration); the maximum summer surface temperature was
13.6 ◦C in the lake littoral. In the middle of September
the homometry (3.9 ◦C) was already recorded. The temperature profiles of Tatra lakes were studied in detail
by Šporka et al. (2006).
The amount of dissolved oxygen did not decrease
below 10 mg L−1 to the 12 m depth during the study period and the maximum concentration was 14.5 mg L−1
at a depth of 10 m in December. Closer to the bot-
-12
-15
-18
Fig. 2. Contour diagrams of the temperature (upper panel, ◦C)
and the concentrations of dissolved oxygen (lower panel, mg L−1 )
in Ľadové pleso during the years 2000–2001. Source: Hydrolab.
tom, these values were reached during the autumn and
spring circulations and summer stratification, but the
concentrations were much lower during the winter stratification: 0.11–6 mg L−1 , with the maximum in January
(Fig. 2).
The annual value of pH varied mostly from 6.6 to
7.0 in the whole water column. The minimal pH of 5.4–
5.8 was measured in interval from the middle of May to
the beginning of June and reached down to the depth
of 4 m. This episodic acidification of the upper layers
was caused by melting of the winter snow/ ice cover.
A maximum value of 8 was first recorded at the depth
of 10–12 m in December, and a second more prolonged
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S206
X
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
6000
4000
10
3000
2000
5
1000
0
0
IX
X
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
TPV [ mm 3 . L -1 ]
5000
Chironomidae
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
7000
TPV (0 m)
TPV (5 m)
TPV (8 m)
TPV (bottom)
2,5
Chironomidae [ ind.m -2 ]
15
X
3,0
7000
Chlorophyll-a (0 m)
Chlorophyll-a (5 m)
Chlorophyll-a (8 m)
Chlorophyll-a (bottom)
Chlorophyll- a [ µg. L -1 ]
IX
XI
20
6000
5000
Chironomidae
2,0
4000
1,5
3000
1,0
2000
0,5
1000
0
0,0
IX
XI
Chironomidae [ ind. m -2 ]
IX
J. Tátosová & E. Stuchlík
X
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
Date
Date
Fig. 3. Seasonal and vertical variability of the concentrations of chlorophyll-a and total volume of particles (TVP) in relation to seasonal
dynamics of chironomid density. Horizontal black and gray bars denote durations of the compact ice cover (black) and melting period
(gray).
60
TPV 13 m
50
TPV [mm-3.m-2.day-1]
maximum was found at the same depth in the middle
of August.
We used the concentration of chlorophyll-a and total volume of seston (TVP) for an expression of the
amount of available food in the lake. Concentrations of
chlorophyll-a in the water column generally fluctuated
between 0 and 5.5 µg L−1 , although an extreme peak
of 18.6 µg L−1 was found in December (Fig. 3.). A second much lower peak was recorded in early July and in
early August in the deeper layers of the water column.
The lowest values of 0–1.8 µg L−1 were observed during the period of winter stratification. For more details
see Nedbalová et al. (2006). The amount of seston expressed as the total volume of particles (TVP) oscillated
between 0.2–1.2 mm3 L−1 in the whole water profile of
Ľadové pleso, but the same December extremely high
peak of 2.6 mm3 L−1 was recoded at the depth of 8 m
and a second lower one just under the water surface at
the end of June. The lowest amount of particles was
found during the winter ice cover period (Fig. 3).
A sedimentary rate of TPV calculated from the
amount of a material captured in the sediment trap
is displayed in Fig. 4. In spite of the December peak
recorded at the 8 m depth, no particles were accumulated in the depth of 13 m over the period December–
February, and in addition, the rest of the winter season
was followed by a very low accumulation of TPV (0.2
mm3 m−2 day−1 ) (Fig. 4). A small increase of TPV
sedimentation (6 mm3 m−2 day−1 ) was first recorded
at the end of winter stratification and the highest values were reached during the spring circulation and
the summer stratification (July – early September) (55
and 41 mm3 m−2 day−1 , respectively). During the autumn overturn, the amount of accumulated material decreased by half values.
40
30
20
10
0
X
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
XII
Date
Fig. 4. Variations of the amount of TPV accumulated in sediment
trap at depth 13 m during the single part of the observed season.
For more details about time intervals of the exposure see Table 2.
Chironomid fauna
In total, four chironomid taxa were identified in the
quantitative samples. Micropsectra radialis Goetghebuer, 1939 dominated the whole year, whereas larvae
of Pseudodiamesa nivosa (Goetghebuer, 1928) were less
abundant overall and were absent in the April and
May samples. Larvae of Procladius (Holotanypus) sp.
were observed in very low densities of 89 ind. m−2 at
the beginning of August and at the end of September
2001. Heterotrissocladius marcidus (Walker, 1856) was
recorded only once in December 2000, with a density of
531 ind. m−2 (Fig. 5).
We obtained 14 chironomid adults, 8 pupae and 12
pupal exuviae of M. radialis and 1 pupal exuvia of P.
nivosa from emergence traps (Tab. 3).
The average density during the sampling period
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7000
7000
Micropsetra radialis
Pseudodiamesa nivosa
Procladius sp.
Heterotrissocladius marcidus
6000
Sampling site A
Sampling site B
Sampling site C
6000
5000
4000
ind m-2
ind. m-2
5000
3000
2000
4000
3000
2000
1000
1000
0
XI
XII
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
0
XI
XII
I
II
Date
III
IV
V
VI
VII
VIII
IX
X
XI
Date
Fig. 5. Changes in the species composition of chironomids in Ľadové pleso during the investigated year (left) and spatial distribution
of larvae in the sedimentary area (right). Sites A and C were situated at the edge of the sedimentary area, site B in the middle of this
area.
Table 3. Catches of emergence traps during the summer period.
Date of trap exposure (starting – final day)
No. of traps
1
2
3
4
5
6
Depth (m)
10
17
18
∼12
9
9
1.–2.VII.
2.–3.VIII.
4.–13.VIII.
13.–29.VIII.
19.–29.IX.
0
0
0
0
0
0
M. radialis (2 PE, 1 P, 1 M, 2 F)
M. radialis (2 PE, 1 P, 2 M, 1 F)
P. nivosa (1 PE), M. radialis (1 P)
M. radialis (3 P, 1 M)
M. radialis (1 PE)
M. radialis (2 P, 2 F)
0
0
0
0
0
0
0
M. radialis (3 PE, 4 F)
M. radialis (2 PE)
0
M. radialis (2 PE, 1 M)
0
0
0
0
0
0
0
Key: PE – pupal exuviae; P – pupae; M – male; F – female. Depth – lake depth above that the traps were installed.
was 1,470 ind. m−2 . At the beginning of the winter stratification in December 2000 the second highest amount of chironomid larvae was collected (2,477
ind. m−2 ); however, no larvae or very low densities of
30–60 ind. m−2 occurred during the rest of the winter
period (Fig. 3). The abundance increased during the
spring circulation (650 ind. m−2 ), doubled during summer stratification, and reached a maximum of 5,927 ind.
m−2 at the beginning of autumn circulation.
The spatial distribution of larvae also varied during the year; in the time of autumn circulations in December 2000 and October 2001 chironomid larvae were
concentrated in the central part of the sediment area,
whereas during the summer stratification in August
and September higher densities were found in marginal
parts of this area (Fig. 5). Several larvae were even observed in the sediment traps at a depth of 13 m in April.
Chironomid life history
Life dynamics could be inferred for the two most abundant taxa: Micropsectra radialis and Pseudodiamesa
nivosa (Fig. 6.). The younger instars of larvae did not
allow a thorough determination of Micropsectra to the
species level, but identification of emerged male and female adults and pupal exuviae suggest that only the
species M. radialis was present. This species reached
an average density of 1,243 ind. m−2 and was the most
abundant chironomid species in the lake. A total of 270
individuals of M. radialis were measured and used for
the analysis of larval instars. Instar analysis (Fig. 6)
suggests that there is one generation per year with
emergence in August (Tab. 3). According to this hypothesis, eggs from adults emerging in August probably hatched over September and reached the 3rd and
4th instars before winter, as evidenced by the presence
of 3rd and 4th instars in December 2000. Growth continued during the winter and spring, since only 4th instar
larvae were found in April and May. The presence of 1st ,
2nd and 3rd instars at the end of August and in September 2001 supports the hypothesis of August emergence
for this species.
We observed also swimming larvae of M. radialis
near the water surface under the ice in April – May.
They appeared a few minutes after we removed snow
cover from the sampling site and stayed there for approximately one hour.
The second most numerous species (an average
density of 126 ind. m−2 ) for which we inferred life
dynamics is Pseudodiamesa nivosa. We sampled and
measured only 30 individuals in total, therefore the reUnauthenticated
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J. Tátosová & E. Stuchlík
Ice
break
Ice
free
13.- 29.VIII
Ice
cover
2.- 3.VIII
Micropsectra radialis
Instars
4
3
2
1
X
XI
XII
I
II
III
IV
V
VI VII VIIIb
VIIIe
IX
%
Ice
Ice
break free
Ice
cover
2.- 3.VIII
Pseudodiamesa nivosa
Instars
4
3
2
1
X
XI
XII
I
II
III IV V
VI VII VIIIb
VIIIe
IX
%
Fig. 6. Instar analyses of Micropsectra radialis (upper panel) and
Pseudodiamesa nivosa (lower panel). Horizontal black and white
bars denote different generations. Black squares with arrows show
observed emergences (see Tab. 3), white square denotes supposed
time of emergence. Sampling months are underlined. (b) – the
beginning of month, (e) – the end of month.
sults of instar analysis provide only a rough estimate
of life history due to the low numbers of individuals.
Emergence probably took place after the ice break in
July, since 1st instar larvae were observed at the turn of
July/August and 2nd and 3rd instar larvae at the end of
August (Fig. 6). Larvae reached the 4th instar probably before winter as evidenced by presence of only these
larvae in December 2000 and September 2001.
Only a few specimens of Procladius sp. and Heterotrissocladius marcidus were found in the profundal
zone of Ľadové pleso, and this low number of individuals did not allow us to infer their life cycle in this lake.
Discussion
Food supply
The winter peak of chlorophyll-a concentration found in
Ľadové pleso is not unusual in high mountain lakes. In
the High Tatra Mts, the phytoplankton and concentrations of chlorophyll-a were studied in three alpine lakes
by Fott et al. (1999). They found high chlorophyll-a
concentrations during the ice-cover period as a result
of sufficient solar radiation penetrating the snowless ice
cover. We observed these conditions at Ľadové pleso at
the beginning of December, when a 30 cm thick layer
of clear ice was created, which allowed the development
of phytoplankton in the lake. The maximum concentration of chlorophyll-a at this time was at a depth of 8
m, possibly due to the high intensity of solar radiation.
This increase of the phytoplankton amount was responsible for a December high peak of TPV at the same
depth. The second peak of chlorophyll-a concentration
in the summer was much lower. This observation may
be explained by different species composition of phytoplankton and different specific chlorophyll-a content in
the phytoplankton cells as a reaction to actual underwater light conditions (Nedbalová et al., (2006). The
other higher value of TPV found in the surface sample at the end of June was connected with the melting
of the ice-cover, when a high amount of allochthonous
material from the ice and the snow entered the lake.
During sedimentation, this material is continuously decomposed, which is probably the reason for the lower
amount of TPV in deeper parts of the lake at the same
time.
Analyses of chlorophyll-a and TPV in vertical samples mainly provide current information on particulate
matter in the water column. Conversely, data from the
sediment traps gives us much more information on the
long-term food supply for benthic animals, because the
short-term increases of TPV recorded in the water column can be followed by a longer period of very low sedimentation, and on a long-term scale the food supply can
be low overall. This is one possible reason why a very
low amount of particles accumulated during the winter
season in spite of the December peak of TPV recorded
at 8 m. The increase of available food for chironomids
is connected with the increased input of allochthonous
material into the ice-free lake and its transport to the
bottom due to spring circulation, and with the development of phytoplankton during the summer season.
Chironomid fauna
The occurrence of Micropsectra radialis, which composed the major part of the profundal fauna in this
lake, is always restricted to cold oligotrophic lakes,
where larvae inhabit both the littoral and profundal
zones (Säwedal, 1982); therefore, the dominance of
this species is not unexpected. The second most abundant chironomid species Pseudodiamesa nivosa is also
considered to be an oligostenothermic species (SerraTosio, 1973) and is typical for ultraoligotrophic and
oligotrophic lakes (Sæther, 1979). In general, the larvae of Procladius often inhabit standing waters and
they are also common in Tatra lakes (Hrabě, 1939,
1942; Gowin & Zavřel, 1944). Although the larvae
of this species did not allow the determination to the
species level, Bitušík (2004) identified the pupal exuviae of just two species P. choreus (Meigen, 1804) and
P. tatrensis (Gowin, 1944) in Tatra lakes. It can be
assumed that larvae found in Ľadové pleso are Procladius tatrensis, which was described by Gowin &
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Seasonal dynamics of chironomids in Ľadové pleso
Zavřel (1944), who found pupae and imagoes only
from Tatra lakes situated above the tree line. The last
recorded species, Heterotrissocladius marcidus, is the
least cold stenothermic member of this genus, but it
is still restricted to relatively cold waters (Sæther,
1975) and together with Procladius are the most common taxa in the High Tatra Mts (Zavřel, 1937), even
though its larvae occur in very low densities (Hrabě,
1939). Paleolimnological studies of Tatra lakes support
that H. marcidus is a stable but not numerous component of the chironomid fauna (Stuchlík et al., 2002,
Šporka et al., 2002; Kubovčík et al., 2003).
Chironomid taxa known from the profundal part
of Ľadové pleso are also found in other high mountain
lakes in Europe. For example, the dominant species in
Ľadové pleso Micropsectra radialis was the only species
found in the profundal part of high mountain Lago di
Latte Lake in the Alps (Cameron et al., 1997). M. radialis together with Heterotrissocladius marcidus, formed
the profundal chironomid assemblage in Lake Redo in
the Pyrenees, and together with Corynoneura arctica
were the only species in the deepest part of Lake La
Caldera (at 3,050 m a.s.l.) in the Sierra Nevada Mts.
(SE Spain) (Rieradevall & Prat, 1999). Similar chironomid compositions are found in deep high mountain
lakes above the tree line in Austria (Bretschko, 1974).
Not only a similar species composition but also low diversity in general is known for high mountain and subarctic lakes. Low numbers of chironomid taxa as were
recorded in Ľadové pleso were also found in the profundal of several north Norwegian lakes (Aagaard, 1986);
for example, in the similarly deep lakes (about 20 m)
Austerdalsvatn and Haukvatn, Heterotrissocladius subpilosus was the only species recorded in the profundal part. Only Procladius sagittalis was collected in the
Pyrenean Aguilo Lake (Cameron et al., 1997). Both
the species composition and low diversity reflect the
specific nature of the altitude and latitude of extremely
located lakes.
The abundance of chironomid larvae usually does
not reach very high values in high mountain lakes
mainly due to the low productivity of these lakes. The
average chironomid abundance of 1,470 ind. m−2 in
the profundal zone of Ľadové pleso is similar to that
recorded by Brundin (1956) in the arctic ultraoligotrophic Lake Kattejaure in northern Sweden, and Lindegaard & Mæhl (1992) found the same density of
1,400 ind. m−2 in the profundal zone of arctic Lake
95 in South Greenland. In the profundal part of the
mentioned north Norwegian lakes, the total number of
chironomids didn’t exceed 1,000 ind. m−2 (Aagaard,
1986). Similarly, high mountain lakes in other parts of
Central Europe have shown chironomid densities of this
magnitude. For example Steinböck (1955) recorded
from 300 to 2,800 ind. m−2 in eight Austrian mountain lakes situated from 2,000 to 2,800 m a.s.l., and
Bretschko (1974) found 2,100 ind. m−2 of chironomids in the Vorderer Finstertaler See (2,237 m a.s.l.).
S209
Seasonal variations
The variability of chironomid abundance was considerable during the study period (from 0 to 5,927 ind. m−2 ),
with the lowest densities recorded within the period
of the winter stratification (November – the beginning
of July), when the concentration of dissolved oxygen
as well as the supply of available food were very low
(in spite of the high concentrations of chlorophyll-a at
the early winter stratification in December). These winter minima of both parameters are in close relationship. As mentioned above, the high concentrations of
chlorophyll-a recorded in December (18.6 µg L−1 ) are
common in mountain lakes (Fott et al., 1999) and
they occur when compact ice cover without snow is
formed, which transmits enough light. The sedimentation and subsequent decomposition of high amounts of
phytoplankton can then cause a decline in the oxygen
content at the bottom of oligotrophic lakes. This low
winter oxygen concentration probably caused the migration of larvae from the sediment to the upper layer
of the water column, as evidenced by the observation
of swimming larvae, and relocation of larvae from the
sedimentary area to the upper part of the lake bottom.
Combined, these effects are probably the reason such
low winter densities of chironomids were found in this
lake. This migrational behavior of chironomid larvae
is one of many adaptations to low oxygen conditions
(Heinis & Crommentuijn, 1992). Such behavior of
chironomids in a lowland Spanish lake has been published by Prat & Rieradevall (1995), but it has not
been described in a mountain lake before.
At the end of the winter stratification the increased
amount of the seston coming from the melting ice cover
entered the lake and the dissolved oxygen concentrations at the lake bottom increased during the following spring circulation. Chironomid fauna responded to
these events with a slight increase in their abundance
from 59 to 649 ind. m−2 at the beginning of August.
This rise of abundance probably occurred due to reversed migration of chironomids to the sedimentary
area as evidenced by the presence of only overwintering
4th instars of the dominant species Micropsectra radialis. Also, the spatial chironomid distribution showed
higher abundances in the marginal part of the sedimentary area then in the central part during this time period. To confirm this migrational hypothesis, a detailed
study would be necessary with the possibility to take
samples from the sublittoral part of the lake bottom,
which is composed of large boulders.
The stable higher concentrations of chlorophyll-a,
TPV and dissolved oxygen and good temperature conditions following the period of summer stratification
established suitable conditions for the development of
the chironomid fauna that reached the maximum abundance (5,927 ind. m−2 ) at the end of September, when
the chironomid populations were composed of individuals of the new generation.
Also, the presence of single species changed durUnauthenticated
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S210
ing the investigated season. As mentioned above, larvae
of M. radialis are typical dwellers of cold oligotrophic
lakes, where they inhabit both the littoral and profundal zones (Säwedal, 1982). Therefore, their stable occurrence in the profundal part of Ľadové pleso during
the whole year was expected. The species Pseudodiamesa nivosa is also a typical inhabitant of ultraoligotrophic and oligotrophic lakes, has been often found in
the littoral part of Tatra lakes (Hrabě, 1939, 1942;
Ertlová, 1987); we also recorded them in abundance
in the littoral of Ľadové pleso. The absence of these
larvae in the profundal zone during winter was presumably a result of the reaction to worsened oxygen conditions as well as to insufficient food supply. P. nivosa
as a predator usually preys on smaller chironomids and
other small organisms. As the littoral part of lakes is
typically colonized by invertebrates more than the deep
profundal zone, it is possible to assume that larvae of
P. nivosa migrated from the profundal zone to the littoral during the winter period, where they stayed until
the time of their emergence in July. This could also be
one reason why we found so few specimens of the 1st
instar in the profundal at the beginning of August.
Even though the larvae of Procladius are common
in Tatra lakes (Zavřel, 1937), very low densities and
only the sporadic presence of this species were recorded
in Ľadové pleso. There is one possible explanation: as
Brooks & Birks (2001) published, the temperature
optimum of this species is about 11 ◦C, which is a temperature that was measured in Ľadové pleso only over
a very short time in the summer and only in the littoral part of the lake. Ľadové pleso probably lies on the
border of the distribution area of this species, and its
densities are affected by inter-annual air temperature
variations.
Life histories
We inferred life cycles for the two most abundant chironomid taxa in Ľadové pleso. Preliminary results of
instar analyses suggest that there is one generation
per year, with emergence of P. nivosa in the July
and M. radialis in the August. According to published
data, this hypothesis could be correct. Moore (1979)
found that chironomids in the subarctic Great Slave
Lake were all univoltine, and the same was reported
by Wiederholm et al. (1977) from a shallow subarctic
lake in northern Sweden. Also, chironomids from other
high mountain lakes in C Europe are univoltine, as observed by Pechlaner et al. (1972) in Vorderer Finstertaler See (2237 m a.s.l.) and Laville & Gaini (1974)
in Lake Port Biehl (Central Pyrenees, 2285 m a.s.l.).
Through the use of ash free dry weight measured
for individual larvae, Lindegaard & Mæhl (1992)
discovered two different cohorts of Micropsetra with
emergence in June and September, which belonged,
however, to the different univoltine species M. brundini and M. groenlandica. On the other hand, it is
known that some species from the cold Holarctic re-
J. Tátosová & E. Stuchlík
gion need more than one year to complete their development (Armitage et al., 1995). For instance, Welch
(1976) found a long life cycle of 3 years for Heterotrissocladius oliveri in the high arctic Lake Char. In subarctic Lake Thingvallavatn in Greenland, Lindegaard
(1992) assumed a 2-year life cycle for Chironomus islandicus, whose 4th instar larvae of both younger and
older generations were distinguished by their average
larval weight. Even though we didn’t weigh collected
animals to confirm or disprove either the bivoltine or
semivoltine life cycle of Micropsectra, that only 4th instar larvae of M. radialis were found in the ice-cover
period and that there was only the one August period
of the M. radialis emergence suggest that there was only
one generation of this species. In addition, the ice free
period of Ľadové pleso lasts 5–6 months, which means
a relatively long growth season for chironomids every
year.
Because of the disappearance of Pseudodiamesa
nivosa larvae from the profundal part of the lake we
have no information about their winter development.
We assume that P. nivosa migrated from the profundal zone to the littoral due to worsening life conditions,
where they probably stayed until the time of their emergence in July. We found a few specimens of the 1st instar in the profundal at the beginning of August, which
suggests that a majority of the population lived in the
littoral after hatching. As was found by Lindegaard
(1992), the growth of the littoral population of this
species can be very fast after hatching. This fast growth
rate in the littoral zone and relatively long ice-free period can support the univoltine life cycle of this species;
however, a more detailed study is necessary to confirm
this hypothesis.
Acknowledgements
We wish to thank P. BITUŠÍK for identifying the Micropsectra species and for revision of the identified chironomid
taxa. We also wish to thank our colleagues for technical assistance during field work and D. HARDEKOPF for linguistic
correction of the manuscript. This study was enabled by the
FP 5 EC project EMERGE (EVK1-CT 1999-00032, address:
www.mountain-lakes.org).
References
AAGAARD, K. 1986. The chironomid fauna of North Norwegian
lakes, with a discussion on methods of community classification. Holarctic Ecology 9: 1–12.
ARMITAGE, P.D., CRASTON, P.S. & PINDER, L.V.C. 1995. The
Chironomidae: Biology and ecology of non-biting midges.
Chapman & Hall, London, 572 pp.
BITUŠÍK, P. 2004. Chironomids (Diptera: Chironomidae) of the
mountain lakes in the Tatra Mts. (Slovakia). A review.
Dipterologica Bohemoslovaca 12, Acta Fac. Ecol., Zvolen 12,
Suppl. 1: 25–33.
BITUŠÍK, P., SVITOK, M., KOLOŠTA, P. & HUBKOVÁ, M. 2006.
Classification of the Tatra Mountain lakes (Slovakia) using
chironomids (Diptera, Chironomidae). Biologia, Bratislava
61, Suppl. 18: S191–S201.
Unauthenticated
Download Date | 6/17/17 7:46 PM
Seasonal dynamics of chironomids in Ľadové pleso
BRETSCHKO, G. 1974. The chironomid fauna of high alpine lake
(Vorderer Finstertaler See, Tyrol, Austria, 2237 m a.s.l.). Entomol. Tidskr., Supplement 95: 22–33.
BROOKS, S.J. & BIRKS, H.J.B. 2001. Chironomid-inferred air
temperatures from Lateglacial and Holocene sites in northwest Europe: progress and problems. Quaternary Science Reviews 20: 1723–1741
BRUNDIN, L. 1956. Die bodenfaunistischen Seetypen und ihre
Anwendbarkeit auf der Südhalbkugel. Zugleich eine Theorie
der produktionsbiologischen Bedeutung der glazialen Erosion.
Rep. Inst. Freshwater Res. Drottingholm 37: 192–235.
CAMERON, N., FJELLHEIM, A., RIERADEVALL, M., RADDUM,
G.G., SCHNELL, O., FOTT, J., STUCHLÍK, E., ČERNÝ, M.
& KOPÁČEK, J. 1997. Contemporary biology, pp. 1–60. In:
WATHNE, B.M., PATRICK, S. & CAMERON, N. (eds) AL:PE –
Acidification of Mountain Lakes: Palaeolimnology and Ecology. Part 2 – Remote Mountain Lakes as Indicators of Air
Pollution and Climate Change, Norwegian Institute for Water Research Report No. 3638, 1997.
DARGOCKÁ, J., KNESLOVÁ, P. & STUCHLÍK, E. 1997. Phytoplankton of several high mountain lakes in different stage of
acidification. Štúdie TANAP 2: 41–62.
DAVIS, I.J. 1984. Sampling aquatic insect emergence, pp. 161–
227. In: DOWNING, J.A. & RIGLER, F.H. (eds) A manual on
methods for the assessment of secondary productivity in fresh
waters, Blackwell Scientific Publications, Oxford, England.
ERTLOVÁ, E. 1964. Príspevok k poznaniu zoobentosu Popradského plesa. Biologia, Bratislava 19: 666–674.
ERTLOVÁ, E. 1987. Chironomids (Chironomidae, Diptera) of the
littoral of the selected lakes in the High Tatras. Acta Fac.
Rerum Nat. Univ. Comen., Zool. 29: 53–66.
FOTT, J., BLAŽO, M., STUCHLÍK, E. & STRUNECKÝ, O. 1999.
Phytoplankton in three Tatra Mountain lakes with different
acidification status. J. Limnol. 52: 107–116.
FOTT, J., PRAŽÁKOVÁ, M., STUCHLÍK, E., & STUCHLÍKOVÁ Z.
1994. Acidification of lakes in Šumava (Bohemia) and in the
High Tatra Mountains (Slovakia). Hydrobiologia, 274: 37–47.
FOTT, J., STUCHLÍK, E. & STUCHLÍKOVÁ, Z. 1987. Acidification of lakes in Czechoslovakia, pp. 77–79. In: MOLDAN, B.
& PAČES, T. (eds) Extended abstracts of the International
workshop on geochemistry and monitoring in representative
basins, Geological Survey, Prague.
GOWIN, F. & ZAVŘEL, J. 1944. Nový Procladius z Vysokých
Tater. Folia Entomol. 7: 8–90.
HEINIS, F. & CROMMENTUIJN, T. 1992. Behavioural responses
to changing oxygen concentrations of deposit feeding chironomind larvae (Diptera) of littoral and profundal habitats.
Arch. Hydrobiol. 124: 173–185.
HRABĚ, S. 1939. Bentická zvířena tatranských jezer. Sborník
Klubu Přírodovědců v Brně 22: 1–13.
HRABĚ, S. 1942. O bentické zvířeně jezer ve Vysokých Tatrách.
Bohemica 25: 123–177.
KNESLOVÁ, P., DARGOCKÁ, J. & STUCHLÍK, E. 1997. Zooplankton of eight the Tatra Mountain lake in different stage of
acidification. Štúdie TANAP 2: 123–134.
KOPÁČEK, J., STUCHLÍK, E. & HARDEKOPF, D. 2006. Chemical composition of the Tatra Mountain lakes: Recovery from
acidification. Biologia, Bratislava 61, Suppl. 18: S21–S33.
KOPÁČEK, J., STUCHLÍK, E., STRAŠKRABOVÁ, V. & PŠENÁKOVÁ, P. 2000. Factors governing nutrient status of mountain
lakes in the Tatra Mountains. Freshwater Biol. 43: 369–383.
KŘEČEK, J., TUREK, J., LJUNGREN, E., STUCHLÍK, E. &
ŠPORKA, F. 2006. Hydrological processes in small catchments
of mountain headwater lakes: The Tatra Mountains. Biologia,
Bratislava 61, Suppl. 18: S1–S10.
KUBOVČÍK, V., BETÁK, M. & FEČKANINOVÁ, G. 2003. Subfosilná fauna pakomárov (Diptera: Chironomidae) Ľadového
plesa (Vysoké Tatry, Slovensko), pp. 201–203. In: BITUŠÍK,
P. & NOVIKMEC, M. (eds) Proc. 13th Conference of Slovak
Limnol. Soc. & Czech Limnol. Soc., Banská Štiavnica, June
2003, Acta Facultatis Ecologiae, Zvolen 10, Suppl. 1.
S211
LAVILLE, H. & GAINI, N. 1974. Phénologie et cycles biologiques
des chironomides de la zone littorale (0–7 m) du lac de PortBielh (Pyrénées centrales). Entomol. Tidskr., Suppl. 95: 139–
155.
LINDEGAARD, C. 1992. Zoobenthos ecology of Thingvallavatn:
vertical distribution, abundance, population dynamics and
production. Oikos 64: 257–304.
LINDEGAARD, C. & MÆHL P. 1992. Abundance, population
dynamics and production of Chironomidae (Diptera) in an
ultraoligotrophic lake in South Greenland. Netherlands J.
Aquat. Ecol. 26 (2–4): 297–308.
MOORE, J.W. 1979. Some factors influencing the distribution,
seasonal abundance and feeding of subarctic Chironomidae
(Diptera). Arch. Hydrobiol. 85: 302–325.
NEDBALOVÁ, L., STUCHLÍK, E. & STRUNECKÝ, O. 2006. Phytoplankton of a mountain lake (Ľadové pleso, the Tatra Mountains, Slovakia): Seasonal development and first indications of
a response to decreased acid deposition. Biologia, Bratislava
61, Suppl. 18: S91–S100.
PECHAR, L. 1987. Use on an acetone : methanol mixture
for the extraction and spectrophotometric determination of
chlorophyll-a in phytoplankton. Arch. Hydrobiol. Suppl. 78:
99–117.
PECHLANER, R., BRETSCHKO, G., GOLLMANN, P., PFEIFER, H.,
TILZER, M. & WEISSENBACH, H.P. 1972. The production
processes in two high-mountain lakes (Vorderer and Hinterer
Finstertaler See, Küthai, Austria), pp. 239–269. In: KAJAK,
Z. & HILLBRICHT-ILKOWSKA, A. (eds) Productivity problems of freshwaters, PWN Pol. Sci. Publ., Warsawa.
PRAT, N. & RIERADEVALL, M. 1995. Life cycle and production
of Chironomidae from the karstic Lake Banyoles (NE Spain).
Freshwater Biol. 33: 511–524.
RADDUM, G.G. & SÆTHER, O.A. 1981. Chironomid communities in Norwegian lakes with different degrees of acidification.
Verh. Int. Verein. Limnol. 21: 399–405.
RIERADEVALL, M. & PRAT, N. 1999. Chironomidae from high
mountain lakes in Spain and Portugal, pp. 605–613. In: HOFFRICHTER, O. (ed.) Late 20th century research on Chironomidae: An Anthology from the 13th International Symposium
on Chironomidae, Shaker Verlag, Aachen.
SÄWEDAL, L. 1982. Taxonomy, morphology, phylogenetic relationships and distribution of Micropsectra Kieffer, 1909
(Diptera: Chironomidae). Entomol. Scand. 13: 371–400.
SÆTHER, O.A. 1975. Nearctic and Palaearctic Heterotrissocladius (Diptera: Chironomidae). Bull. Fish. Res. Board Can.
139: 27–36.
SÆTHER, O.A. 1979. Chironomid communities as indicators of
lake typology. Verh. Int. Verein. Limnol. 19: 3127–3133.
SERRA-TOSIO, B. 1973. Ecologie et biogeography des Diamesini
d’Europe (Diptera, Chironomidae). Trav. Lab. Hydrobiol.
Piscic. Univ. Grenoble 63: 5–175.
STEINBÖCK, O. 1955. Über die Verhältnisse in der Hochgebirgsseen. Mem. Inst. Ital. Idrobiol., Suppl. 8: 311–343.
STUCHLÍK, E., APPLEBY, P., BITUŠÍK, P., CURTIS, C., FOTT, J.,
KOPÁČEK, J., PRAŽÁKOVÁ, M., ROSE, N., STRUNECKÝ, O.
& WRIGHT, R.F. 2002. Reconstruction of long-term changes
in lake water chemistry, zooplankton and benthos of a small,
acidified high-mountain lake: Magic modeling and paleolimnological analysis. Water Air Soil Poll.: Focus 2: 127–138.
STUCHLÍK, E., STUCHLÍKOVÁ, Z., FOTT, J., RŮŽIČKA, L. &
VRBA, J. 1985. Effect of acid precipitation on waters of the
TANAP territory. Zborník TANAP 26: 173–211.
ŠPORKA, F., LIVINGSTONE, D.M., STUCHLÍK, E., TUREK, J. &
GALAS, J. 2006. Water temperatures and ice cover in lakes
of the Tatra Mountains. Biologia, Bratislava 61, Suppl. 18:
S77–S90.
ŠPORKA, F., ŠTEFKOVÁ, E., BITUŠÍK, P., THOMPSON, A.R.,
AGUSTI-PANAREDA, A., APPLEBY, P., GRYTNES, J.A., KAMENIK, C., KRNO, I., LAMI, A., ROSE, N. & SHILLAND, N.E.
2002. The paleolimnological analysis of sediment from high
mountain lake Nižné Terianske pleso in the High Tatras (Slovakia). J. Paleolimnol. 28: 95–109.
Unauthenticated
Download Date | 6/17/17 7:46 PM
S212
TÁTOSOVÁ, J. 2002. Makrozoobentos profundálu jezer v oblasti
Vysokých Tater. Thesis, Faculty of Science, Charles University in Prague, 66 pp.
TUREK, J. 2002. Hydrologický režim vysokohorských jezer
v oblasti Vysokých Tater. Thesis, Faculty of Science, Charles
University in Prague, 82 pp.
J. Tátosová & E. Stuchlík
WELCH, H.E. 1976. Ecology of Chironomidae (Diptera) in a polar
lake. J. Fish. Res. Board Can. 33: 227–247.
WIEDERHOLM, T., DANELL, K. & SJÖBERG, K. 1977. Emergence
of chironomids from a small man-made lake in northern Sweden. Norw. J. Entomol. 24: 99–105.
ZAVŘEL, J. 1937. Orthocladiinen aus der Hohen Tatra. Verh. Int.
Verein. Limnol. 7: 483–496.
Received September 2, 2005
Accepted May 9, 2006
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