Table 1 The river length and lake area that support anadromous brown trout, as well as the catchment area of each study population, all of which drain into Sognefjorden, Norway. An overview of the Salmo trutta smolts and veteran migrants marked with acoustic tags, during the sampling years 2012 – 2015 is also stated
River | Aurland | Lærdal | Årdal | Fortun | Mørkrid |
|---|---|---|---|---|---|
Catchment area (km2) | 804 | 1184 | 981 | 508 | 288 |
Mean annual discharge (m3 s−1) | 37.6 | 36.4 | 46.1 | 28.5 | 12 |
River length (km) | 10 | 25 | 30 | 16 | 9.5 |
Lake area (km2) | 1.9 | 0 | 7.5 | 0.62 | 0 |
Distance from river mouth to outermost receiver (km) | 160 | 167 | 181 | 209 | 209 |
Number smolts detected (%) | 69 (81) | 12 (63) | 42 (84) | 40 (80) | 12 (80) |
Number migrant smolts (%) | 37 (54) | 11 (92) | 22 (52) | 23 (58) | 7 (58) |
Total length (cm) (mean, range) | 20.1, 12 – 29 | 19.5, 12 – 27 | 15.6, 12 – 27 | 18.2, 11 – 26 | 19.6, 15 – 24 |
Fulton's K (mean ± SD (N)) | 0.80 ± 0.16 (34) | 0.78 ± 0.07 (6) | 0.79 ± 0.11 (10) | 0.86 ± 0.08 (16) | NA (0) |
N veteran migrant brown trout detected (%) | 85 (96) | 118 (98) | 76 (99) | 63 (91) | NA |
N migrant veteran brown trout (%) | 49 (58) | 63 (54) | 52 (68) | 41 (65) | NA |
N return to freshwater (%) | 41 (84) | 53 (84) | 45 (87) | 23 (56) | NA |
Total length (cm) (mean, range) | 39.9, 24 –76 | 44.3, 22 – 74 | 40.7, 25 – 69 | 48.9, 26 – 86 | NA |