Danish Institute for Fisheries Research Sea trout Country report - Denmark Baltic Sea Trout Workshop in Kotka, 31. May 2. June 26
Danish part of the Baltic Populations of trout from outside the Baltic area are known to move south into the Baltic Jutland Funen Zealand 23 Sweden 24 25 Bornholm 22 Germany Poland
Example from Karup Å Limfjord River Karup Kattegat North Sea Baltic Sea 3 6 12 Kilometer
Recapture positions of trout tagged in Karup Å Symbols F1 F1_smolt Wild Events Hatchery Damsmolt Events Wild Vildsmolt Events Adults Havorred Events 45 9 18 Kilometer
Official landings of sea trout Danish catches of sea trout in the Baltic 12 1 8 6 199-1998 Incl.rainbow trout 1985-1998 Including catch by non-professionals 4 2 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 21 23 25
Official catches of sea trout 1997-25 12 16 1 14 12 8 1 Kg 6 8 Value (DKK) Baltic Total Denmark Value Baltic 4 6 4 2 2 1997 1998 1999 2 21 22 23 24 25
Distribution of landed Baltic sea trout 3 25 25 2 2 Kg 15 15 1 Price (DKK)/Kg Landing Avg. price 1 5 5 Bornholm Zealand Funen South Jutland East Jutland Other
Catch of sea trout in sports fishery
Catch of sea trout in sport fishery Sport fishery landings index 2,5 2 Number 1,5 1 Kolding (1991-25=1) Horsens (1994-24=1) Vejle (1988-24=1),5 1988 199 1992 1994 1996 1998 2 22 24
Catch of sea trout in broodstock fishery
Catch of sea trout in broodstock fishery N 4 35 3 25 2 15 1 5 Karup - Number / index of sea trout in broodstock-fishery 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 Note sample only. Post fishing spawner abundance in 1996-97 approx. 9
Sea trout size distribution Karup - Length of sea trout in broodstock fishery 12 1 8 6 4 2 1985 199 1995 2 25
Regulations a few of them Minimum size 4 cm total length Mature and maturing seatrout closed season 16 Nov 15 Jan. Recreational fishery only for own use 5 m closed area around river mouths + many local regulations No nets -1 m from coast Stop nets (for otter) in fyke-nets Grids in entrances to fish-farms Upper edge of pound net below surface in spring
Regulations closed area Width of river > 2m: all year Width of river < 2 m: 16. Sep. 15. March
Regulations rivers + gear Entrance not in upstream direction March - May Recreational fishery only
Regulations recreational fishery
Regulations Case Simested å Dk kort gælder fra 1 aug 94 Permanent fra 98 Closed area extended from august 1994
Regulations - Case Simested å. 6 5 Number / index of sea trout 4 3 2 1 Extended area closed for fishing 1982 1984 1986 1988 199 1992 1994 1996 1998 2 Sea trout caugth by electric fishing
Regulations - Case Karup å. Fredning udvidet fra 1986 Fra 89 permanent Closed area extended June 1986
Size distribution of sea trout in broodstock fishery Karup Å 1986 1999.25.25.2.2.15.15.1.1.5.5 3 35 4 45 5 55 6 65 7 75 8 85 9 95 1 15 11 115 3 35 4 45 5 55 6 65 7 75 8 85 9 95 1 15 11 115 Karup - Number / index of sea trout in broodstock-fishery 4 35 3 25 N 2 15 1 5 1986 1987 1988 1989 199 1991 1992 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 1 m line closed area all year from 1986 - closed in winter months from 1978-1986
Stocking of fish Trout stockings in Denmark, 1987-25 (Thousands) 2 18 16 14 Numbers 12 1 8 6 4 2 1987 1989 1991 1993 1995 1997 1999 21 23 25 Year Fry ½-yearlings Yearlings 2-years River Mouth Coast
Improvement measures habitat examples
Origin of sea trout - Baltic Total smolt production 8 7 6 5 4 3 2 1 2 21 22 23 24 25 Wild River released as fry, ½ - and 1 year old River mouth rel.
Wild production by area Wild production 25 2 15 1 Jutland Funen Zealand Bornholm 5 2 21 22 23 24 25
Origin - river releases by area Smolt from river releases of fry, ½- and 1 - year old 7 6 5 4 3 Jutland Funen Zealand 2 1 2 21 22 23 24 25
Origin - river mouth releases by area River mouth releases 6 5 4 3 2 Jutland Funen Zealand 1 2 21 22 23 24 25
Status of rivers by area Bornholm Zealand 14 3 12 25 1 8 6 4 Good Satisf Poor 2 15 1 Good Satisf Poor 2 5 2 21 22 23 24 25 2 21 22 23 24 25 Funen Jutland 2 8 18 16 14 12 1 8 6 4 2 Good Satisf Poor 7 6 5 4 3 2 1 Good Satisf Poor 2 21 22 23 24 25 2 21 22 23 24 25
Monitoring of rivers in Baltic area Bornholm 18 streams 36 sites annually Zealand 253 streams 734 sites 7 year interval Funen 7 streams 411 sites 7 year interval Jutland 176 streams 16 sites 7 year interval Zealand, Funen and Jutland: additional monitoring by counties and municipalities
Threats Flow lack of habitat Eastern part (Bornholm, Zealand) Bird predation All areas (heron) western part (heron, cormorant) Habitat quality Western part: silting of spawning grounds, modification of habitats, maintenance of streams
Threats Illegal fishing All areas recently proven in Jutland and Funen Access to spawning grounds Diminishing - mostly western part (Jutland) Downstream passage Fish farms, water mills, lakes mostly western part (Jutland)
Outcome of releases - taggings
Outcome of releases - Gudenå River and river related releases 8 7 6 Recapture % 5 4 3 Fjord River Mouth River Upper River 2 1 198 1985 199 1995 2
Outcome of releases various rivers Various rivers 16 14 12 Recapture % 1 8 6 4 2 1975 198 1985 199 1995 2
Outcome of releases sea releases Various sea releases 18 16 14 12 Rec % 1 8 6 4 2 1981 1982 1983 1984 1985 1986 1987 1988 1989 199 1991
Research present and recent areas of work Habitats Origin (wild vs hatchery) - Genetics Negotiation of: Weirs Fjords Predators
Needs for research Index river: smolt production of stocked and wild trout Spawning escapement Model for sea- and freshwater survival Sea trout biology in the sea (black/grey box) Modelling habitat quality (possibly by RHYHABSIM) Habitat work: natural and regulated rivers; rivers with differing discharge pattern Development of methods to tag small fish Exchange of experience in restoring populations and habitats in rivers Exchange of research knowledge / methods
Danish Institute for Fisheries Research