Farmed Atlantic salmon Salmo salar L. parr may reduce early survival of wild fish.
The study examined the density-mediated effects on growth, survival and dispersal of wild and farmed Atlantic salmon Salmo salar offspring in the period immediately following emergence, using a substitutive design. In small confined stream channels, wild parr coexisting with farmed parr had a significantly poorer survival, than wild parr alone. Density did not affect this relationship. In larger unconfined stream channels, wild parr coexisting with farmed parr entered a downstream trap in higher numbers than wild parr in allopatry. The results suggests that during the earliest life stages, farmed S. salar can outcompete wild S. salar, resulting in a reduced survival of wild S. salar.
Norwegian Institute for Nature Research (NINA), N-7485 Trondheim, Norway.
L
L
Sundt-Hansen
Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
J
J
Huisman
Laboratory of Freshwater Ecology and Inland Fisheries (LFI-Uni Environment), Uni Research, N-5006 Bergen, Norway.
H
H
Skoglund
Norwegian Institute for Nature Research (NINA), N-7485 Trondheim, Norway.
K
K
Hindar
D000818:Animals; D000835:Animals, Wild / Q000254:growth & development*; D017756:Aquaculture; D018533:Biomass; D049628:Body Size; D003163:Competitive Behavior; D003247:Conservation of Natural Resources; D011156:Population Density; D020317:Salmo salar / Q000254:growth & development*
aquaculture; competition; density dependence; juvenile; salmonids; survival