Arev employees wrote an article in Vísbendingu about the distribution of salmon this year after a release event in Kvígindisdal last summer. It turned out that salmon spread west and east from Patreksfjörður.
In the picture you can see which salmons were distributed in fishing places (years), but the picture shows 457 salmon caught and their distribution is obtained from http://www.strokulax.is. About 22% of the salmon went west and 78% went east. The median distance of salmon going east was 268 km, while those going west was 171 km. Much more fertile rivers are on the east side and at the same time ocean currents run clockwise around the country.
Arev's previous article in Evidence on the risk assessment of genetic mixing