Table 1
Volume of Lake Tegel 5 to 16 m under surface Northeastern area limited by the islands Scharfenberg and Reiswerder.
Depth (m) | Area (106m2) | Volume (106m3) |
5 | 1,862 | 1,866 |
6 | 1,769 | 1,674 |
7 | 1.612 | 1.531 |
8 | 1.450 | 1.313 |
9 | 1.175 | 1.087 |
10 | 1.0 | 0.916 |
11 | 0.831 | 0.763 |
12 | 0.694 | 0.597 |
13 | 0.5 | 0.381 |
14 | 0.262 | 0.168 |
15 | 0.075 | 0.047 |
16 | 0.019 | 0.010 |
∑10.353 |
Table 2
Percentage composition of commercial fishes from Lake Tegel in 1982 to 1985 and yield of Lake Tegel plus upper Havel, total area of 700 ha.
Fish species | % of valuable fish | Stocking | ||||
1982 | 1983 | 1984 | 1985 | 1984 | 1985 | |
Eel (Anguilla anguilla) | 27 | 31 | 28 | 34 | 890 kg = 44 500 ind. | 890 kg = 44 500 ind. |
Roach (Rutilus rutilus) | 37 | 34 | 41 | 28 | ||
Pikeperch (Stizostedion lucioperca) | 13 | 16 | 20 | 23 | ||
Bream (Abramis brama) and White bream (Blicca björkna) | 16 | 12 | 5 | 7 | ||
Pike (Esox lucius) | 3 | 3 | 2 | 2 | 3 350 ind. | 2 520 ind. |
Perch (Perca fluviatilis) | 1 | 1 | 1 | 3 | ||
Tench (Tinca tinca) | 1 | 1 | 1 | 1 | 100 kg | 300 kg |
Carp (Cyprinus carpio) | 1 | 1 | - | - | ||
European catfish (Silurus glanis) | 1 | 1 | 1 | 1 | 400 kg | 350 kg |
Valuable fish (kg) | 17 392 | 18 956 | 19 863 | 18 102 | ||
Coarse fish (kg) | 69 380 | 48 725 | 71 360 | 54 020 | ||
Total yield (kg) | 86 772 | 67 681 | 91 223 | 72 122 |
Table 3
Trawl catches during the EIFAC Intercalibration Exercise on Lake Tegel
Trawl haul No. | Towing course | depth | Stizostedion lucioperca | Aspius aspius | Hypophthalmichthys molitrix | Alburnus alburnus | Abramis brama | Acerina cernua | Blicca bjorkna | Anguilla anguilla | Type of trawl | Osmerus eperlanus | Perca fluviatilis | Rutilus rutilus |
1 | Greenwich | 0 | - | - | - | - | 25 | - | 11 | - | PMT | - | - | - |
2 | Hasselwerder-Sees. | 0 | 2 | - | - | - | 19 | - | 247 | - | PMT | - | - | 3 |
3 | Hasselwerder | 0 | - | - | - | - | 52 | 12 | 33 | - | YFT | - | - | - |
4 | Greenwich | 0 | - | - | - | 1 | 9 | 15 | - | - | YFT | 1 | - | 2 |
5 | Greenwich | 0 | - | - | - | - | 8 | 2 | 3 | - | CVT | - | 1 | - |
6 | Hasselwerder-Sees. | 0 | - | - | - | - | 12 | 2 | 17 | - | CVT | 1 | 1 | 1 |
7 | Greenwich | 5 | 1 | - | - | 1 | 110 | 23 | 66 | - | CVT | - | 2 | 1 |
8 | Hasselwerder | 5 | 1 | - | - | - | 231 | 31 | 671 | - | CVT | - | 3 | 4 |
9 | Hasselwerder | 5 | - | - | - | 1 | 71 | 21 | 59 | - | YFT | - | - | - |
10 | Greenwich | 5 | 1 | - | - | - | 59 | 210 | 19 | - | YFT | 1 | 1 | - |
11 | Greenwich | 5 | - | - | - | - | 46 | 1 | 27 | - | PMT | - | 1 | 2 |
12 | Hasselwerder | 5 | - | - | - | - | 29 | - | 143 | - | PMT | - | - | - |
13 | Hasselwerder | 10 | - | - | - | - | 17 | - | 16 | - | PMT | - | - | - |
14 | Greenwich | 10 | - | - | - | - | 31 | - | 36 | - | PMT | - | - | - |
15 | Greenwich | 10 | - | - | - | - | 15 | 8 | 1 | - | YFT | - | - | - |
16 | Hasselwerder | 10 | 3 | - | - | - | 9 | 5 | - | 1 | YFT | - | 1 | - |
17 | Hasselwerder | 10 | - | - | - | - | 9 | - | 4 | - | CVT | - | - | - |
18 | Greenwich | 10 | 1 | - | - | - | 25 | 66 | 11 | 3 | CVT | - | 1 | - |
19 | Reiswerder | 5 | 4 | - | 1 | - | 480 | - | 3792 | 1 | CVT | - | 1 | - |
20 | " | 5 | - | - | - | - | 36 | 107 | 61 | - | YFT | 1 | 3 | - |
21 | " | 5 | 1 | - | - | - | 42 | - | 426 | - | PMT | - | - | 3 |
22 | " | 0 | - | 1 | - | - | 33 | - | 450 | - | PMT | - | - | 12 |
23 | " | 0 | - | - | - | 2 | 18 | 4 | 32 | - | YFT | 1 | - | - |
24 | " | 0 | - | - | 1 | 1 | 19 | 4 | 100 | - | CVT | - | - | 3 |
25 | " | 10 | 3 | - | 1 | - | 216 | 1 | 81 | - | CVT | - | - | 1 |
26 | " | 10 | 1 | - | - | - | 23 | 7 | 13 | - | YFT | 1 | 1 | - |
27 | " | 10 | - | - | - | - | 51 | - | 105 | - | PMT | - | 1 | 1 |
18 | 1 | 3 | 6 | 1695 | 519 | 6424 | 5 | 6 | 17 | 35 |
Total: 8729 fishes
Table 4
Arrangement of the 8 different mesh sizes (mm) in the gill net from the type “Latin Square”.
17 | 56 | 44 | 13 | 27 | 21 | 10 | 34 |
27 | 13 | 10 | 21 | 34 | 56 | 44 | 17 |
10 | 34 | 56 | 17 | 13 | 44 | 27 | 21 |
44 | 21 | 27 | 34 | 17 | 10 | 13 | 56 |
Table 5
Mark-recapture data for all catches cumulated.
m = numbers of marked fish; c = fish checked for marks;
r = recaptured fish; N = population estimate for all length groups
of marked fish; s = standard deviation of N;
Ncm = population estimates for single cm-groups; B = biomass
Bream | White Bream | Roach | sum/mean | |
3 126 | 14 498 | 10 583 | 28 207 | |
8 765 | 26 502 | 581 | 35 848 | |
132 | 947 | 78 | 1 157 | |
0.048 | 0.073 | 0.009 | 0.048 | |
181 956 | 361 768 | 61 343 | 605 067 | |
15 590 | ** | 6 360 | ||
159 888 | 362 253 | 66 581 | 588 722 | |
B (kg) | 41 571 | 43 479 | 10 115 | 95 165 |
B (kg/ha) | 139 | 145 | 34 | 317 |
* 8 % mortality calculated
** a single standard deviation is not available because the estimate is calculated from 3 independent estimates
Table 6
Numbers of caught fish
Young Fish Trawl | Key of hauls | A. cernua | B. björkna | A. brama | others |
} T1 – T27 | 388 | 218 | 293 | 24 | |
P. Midwater Trawl | 1 | 1460 | 293 | 39 | |
C. Vendace Trawl | 129 | 4745 | 1110 | 39 | |
Seine | S1 | 214 | 5077 | 1477 | 401 |
Gill-net | G1 – G3 | 126 | 348 | 80 | 70 |
Total | 858 | 11848 | 3253 | 573 |
Table 7
Modal length (cm) of the fishes from different nets
A. cernua | B. björkna | A. brama | Total fish | |
Young Fish Trawl | 5 | 17 | 21 | 5 ; 17 |
PM-Trawl | - | 17 | ? | 17 |
C. Vendace Trawl | 9 | 17 | 20.5 | 8 ; 18 |
Seine 1 | 8.5 | 17 | 22.5 | 17 |
Gill net | 6 | 16 | ? | 6 ; 16.5 |
Table 8
Mean sizes of 3 fish species from hauls differing in respect to gear, trawling depth and region of Lake Tegel
Duration of trawling (min.) | A. brama 11 – 31 cm | A. cernua 4 – 10 cm | B. björkna 12 – 21 cm | |
Young Fish Trawl | 135 | 20.2 ± 4.2 | 6.1 ± 1.5 | (17.1 ± 1.8) |
PM -Trawl | 158 | 20.8 ± 5.0 | 16.8 ± 1.8 | |
C. Vendace Trawl | 157 | (21.1 ± 3.1) | (8.1 ± 1.2) | (17.2 ± 2.6) |
Surface | 188 | 21.4 ± 5.1 | 6.4 ± 1.6 | (16.6 ± 1.9) |
5 m | 160 | (20.4 ± 4.2) | 5.9 ± 1.5 | 17.0 ± 1.8 |
10 m | 102 | (20.8 ± 3.3) | 7.3 ± 1.8 | 17.9 ± 1.6 |
Trawl-transect 1 | 157 | 21.2 ± 5.5 | 6.6 ± 1.7 | 17.3 ± 1.7 |
Trawl-transect 2 | 130 | 19.8 ± 4.0 | (7.0 ± 3.7) | 17.0 ± 1.7 |
Trawl-transect 3 | 163 | 20.0 ± 5.8 | (5.9 ± 1.3) | (16.6 ± 2.9) |
( ) = size distribution deviates from normality
Table 9
Regional fish density from the single-beam system. Compare Figure 7
Transect | Fish/ha | Date (Nov.) |
1 | 1361 | 13 |
2 | 3682x | 13 |
3 | 2148 | 13 |
I-J | 925 | 13 |
G-H | 2775 | 13 |
H-J | 582 | 13 |
D-C | 362 | 14 |
F-E | 1769 | 14 |
H-G | 2374 | 14 |
J-I | 2969 | 14 |
L-K | 606 | 14 |
Table 10
Population estimates of fish in Lake Tegel from dual-beam system. Density estimates scaled by depth (vertical stratification). TS ≥ -58 dB
Date | Day/Night | Frequency kHz | Population Size n × 103 | 95% Confidence Limits n × 103 |
11/12 | D | 420 | 483 | 226 |
11/12 | N | 420 | 213 | 93 |
11/13 | N | 420 | 385 | 198 |
11/12–13 | N | 420 | 310 | 115 |
11/14 | N | 120 | 624 | 312 |
Table 11
Selected estimates of overall-fish population in Lake Tegel in November 1985
Method | Fish size ≥ cm | Mortality % | Fish Population n × 10 3 | Confidence Limits | excluding | |
n × 103 | level % | |||||
dual-beam | 2 | 310 | 195 – 425 | 5 | surface layer, | |
single-beam | 4 | 393 | 226 – 682 | 5 | inshore, bottom | |
mark - recapture | 13;11;16 | 8 | 605 | 521 – 689 | 20 | others than bream, |
2 | 645 | 554 – 736 | 20 | white bream, roach |