Environmental threats and conservation implications for Atlantic salmon and brown trout during their critical freshwater phases of spawning, egg development and juvenile emergence

Atlantic salmon Salmo salar L. and brown trout trutta fario are species of high socio-economic ecological value. Declining populations make them target fisheries management. This paper reviews the direct effects deficient longitudinal connectivity, changes in discharge, water temperatures, oxygen depletion, chemistry increasing loads fine sediment on critical life stages spawning, egg incubation emergence. It further provides an overview about basic autecological requirements summarises important thresholds physico-chemical tolerances. collection information baselines for assessing historical, ongoing new threats relevant management both fresh waters. Critical early-life almost identical, creating synergies conservation restoration. Seaward-migrating forms exposed to stressors, but improving starting conditions can also greatly improve their resilience.