Details of the hauls and the numbers of each of the different species caught in series I to III given in Tables 1, 2 and 3. In these tables Y.F.T. stands for the Young Fish Trawl, C.V.T. stands for Commercial Vendace Trawl and the asterisk indicated that the depth of the headline was controlled by suspending the trawl from floats at the surface on a line 6 m long. The whitefish were not identified to species and in the tables are given as C. lavaretus +.
Table 1
Details of the hauls made in series I on 5–6 September 1980, and the number of each species caught
Haul | 1 | 2 | 3 | 4 | 5 |
Trawl | Y.F.T. | Y.F.T. | Y.F.T. | Y.F.T. | Y.F.T. |
Time shot | 22.45 | 23.27 | 00.11 | 00.47 | 01.34 |
Time hauled | 22.58 | 23.43 | 00.26 | 01.07 | 01.55 |
Duration (min) | 13 | 16 | 15 | 20 | 21 |
Towing warp length (m) | 75 | 100 | 125 | 150 | 75 |
Depth of headline (m) | 9 | 13 | 17 | 20 | 4 |
Distance between boats (m) | 60 | 60 | 75 | 75 | 60 |
Catch | |||||
Lampetra fluviatilis | 2 | 1 | 18 | 4 | - |
Coregonus albula | 4 | 1 | 10 | 47 | - |
C. lavaretus + | 1 | 1 | 12 | - | |
Osmerus eperlanus | 34 | 30 | 168 | 204 | 795 |
Perca fluviatilis | 2 | 6 | - | 16 | 6 |
Gymnocephalus cernua | 1 | 4 | 4 | 227 | 2 |
Cottus gobio | - | - | - | 15 | - |
Total fish | 43 | 43 | 201 | 525 | 803 |
Fish/1 000 m3 | 1.40 | 1.36 | 6.31 | 14.17 | 16.13 |
Table 2
Details of the hauls made in series II on 7–8 September 1980, and the number of each species caught
Haul | 6 | 7 | 8 | 9 |
Trawl | C.V.T. | C.V.T. | Y.F.T. | Y.F.T. |
Time shot | 20.43 | 22.00 | 23.02 | 00.21 |
Time hauled | 21.04 | 22.20 | 23.15 | 00.35 |
Duration (min) | 17 | 20 | 13 | 14 |
Towing warp length (m) | 150 | 100* | 125 | 100* |
Depth of headline (m) | 16 | 6 | 17 | 6 |
Distance between boats (m) | 75 | 60 | 75 | 60 |
Catch | ||||
Lampetra fluviatilis | - | - | 24 | - |
Coregonus albula | 152 | 2 | 20 | 1 |
C. lavaretus + | 40 | 2 | - | |
Osmerus eperlanus | - | 25 | 69 | 757 |
Salmo trutta | - | 1 | - | - |
Perca fluviatilis | 1 | 1 | - | 3 |
Gymnocephalus cernua | 4 | - | - | - |
Cottus gobio | 3 | - | - | - |
Total fish | 200 | 29 | 115 | 761 |
Fish/1 000 m3 | 2.79 | 0.33 | 4.16 | 27.51 |
Table 3
Details of the hauls made in series III on 8–9 September 1980, and the number of species caught
Haul | 10 | 11 | 12 | 13 | 14 |
Trawl | C.V.T. | C.V.T. | C.V.T. | Y.F.T. | Y.F.T. |
Time shot | 20.53 | 21.35 | 22.19 | 23.22 | 23.59 |
Time hauled | 21.04 | 21.48 | 22.35 | 23.38 | 00.10 |
Duration (min) | 11 | 13 | 16 | 16 | 11 |
Towing warp length (m) | 150 | 100* | 150 | 125 | 100* |
Depth of headline (m) | 16 | 6 | 16 | 17 | 6 |
Distance between boats (m) | 75 | 60 | 75 | 75 | 60 |
Catch | |||||
Lampetra fluviatilis | - | - | - | 16 | - |
Coregonus albula | 70 | 9 | 90 | 12 | 1 |
C. lavaretus + | 10 | 3 | 16 | 3 | - |
Osmerus eperlanus | - | 5 | 1 | 164 | 810 |
Salmo trutta | - | - | 1 | - | - |
Perca fluviatilis | - | - | - | 2 | 5 |
Gymnocephalus cernua | - | - | - | 3 | - |
Total fish | 80 | 17 | 108 | 200 | 816 |
Fish/1 000 m3 | 1.72 | 0.30 | 1.60 | 5.89 | 37.54 |